/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2007 by Janne Karhu.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/physics/particle_edit.c
 *  \ingroup edphys
 */


#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <assert.h>

#include "MEM_guardedalloc.h"

#include "DNA_scene_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_view3d_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"

#include "BLI_math.h"
#include "BLI_lasso.h"
#include "BLI_listbase.h"
#include "BLI_string.h"
#include "BLI_kdtree.h"
#include "BLI_rand.h"
#include "BLI_utildefines.h"

#include "BKE_context.h"
#include "BKE_depsgraph.h"
#include "BKE_DerivedMesh.h"
#include "BKE_global.h"
#include "BKE_object.h"
#include "BKE_mesh.h"
#include "BKE_modifier.h"
#include "BKE_particle.h"
#include "BKE_report.h"
#include "BKE_bvhutils.h"
#include "BKE_pointcache.h"

#include "BIF_gl.h"
#include "BIF_glutil.h"

#include "ED_object.h"
#include "ED_physics.h"
#include "ED_mesh.h"
#include "ED_particle.h"
#include "ED_view3d.h"

#include "UI_resources.h"

#include "WM_api.h"
#include "WM_types.h"

#include "RNA_access.h"
#include "RNA_define.h"

#include "physics_intern.h"

void PE_create_particle_edit(Scene *scene, Object *ob, PointCache *cache, ParticleSystem *psys);
void PTCacheUndo_clear(PTCacheEdit *edit);
void recalc_lengths(PTCacheEdit *edit);
void recalc_emitter_field(Object *ob, ParticleSystem *psys);
void update_world_cos(Object *ob, PTCacheEdit *edit);

#define KEY_K					PTCacheEditKey *key; int k
#define POINT_P					PTCacheEditPoint *point; int p
#define LOOP_POINTS				for (p=0, point=edit->points; p<edit->totpoint; p++, point++)
#define LOOP_VISIBLE_POINTS		for (p=0, point=edit->points; p<edit->totpoint; p++, point++) if (!(point->flag & PEP_HIDE))
#define LOOP_SELECTED_POINTS	for (p=0, point=edit->points; p<edit->totpoint; p++, point++) if (point_is_selected(point))
#define LOOP_UNSELECTED_POINTS	for (p=0, point=edit->points; p<edit->totpoint; p++, point++) if (!point_is_selected(point))
#define LOOP_EDITED_POINTS		for (p=0, point=edit->points; p<edit->totpoint; p++, point++) if (point->flag & PEP_EDIT_RECALC)
#define LOOP_TAGGED_POINTS		for (p=0, point=edit->points; p<edit->totpoint; p++, point++) if (point->flag & PEP_TAG)
#define LOOP_KEYS				for (k=0, key=point->keys; k<point->totkey; k++, key++)
#define LOOP_VISIBLE_KEYS		for (k=0, key=point->keys; k<point->totkey; k++, key++) if (!(key->flag & PEK_HIDE))
#define LOOP_SELECTED_KEYS		for (k=0, key=point->keys; k<point->totkey; k++, key++) if ((key->flag & PEK_SELECT) && !(key->flag & PEK_HIDE))
#define LOOP_TAGGED_KEYS		for (k=0, key=point->keys; k<point->totkey; k++, key++) if (key->flag & PEK_TAG)

#define KEY_WCO					((key->flag & PEK_USE_WCO) ? key->world_co : key->co)

/**************************** utilities *******************************/

int PE_poll(bContext *C)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);

	if (!scene || !ob || !(ob->mode & OB_MODE_PARTICLE_EDIT))
		return 0;
	
	return (PE_get_current(scene, ob) != NULL);
}

int PE_hair_poll(bContext *C)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit;

	if (!scene || !ob || !(ob->mode & OB_MODE_PARTICLE_EDIT))
		return 0;
	
	edit= PE_get_current(scene, ob);

	return (edit && edit->psys);
}

int PE_poll_view3d(bContext *C)
{
	ScrArea *sa = CTX_wm_area(C);
	ARegion *ar = CTX_wm_region(C);

	return (PE_poll(C) &&
	        (sa && sa->spacetype == SPACE_VIEW3D) &&
	        (ar && ar->regiontype == RGN_TYPE_WINDOW));
}

void PE_free_ptcache_edit(PTCacheEdit *edit)
{
	POINT_P;

	if (edit==0) return;

	PTCacheUndo_clear(edit);

	if (edit->points) {
		LOOP_POINTS {
			if (point->keys)
				MEM_freeN(point->keys);
		}

		MEM_freeN(edit->points);
	}

	if (edit->mirror_cache)
		MEM_freeN(edit->mirror_cache);

	if (edit->emitter_cosnos) {
		MEM_freeN(edit->emitter_cosnos);
		edit->emitter_cosnos= 0;
	}

	if (edit->emitter_field) {
		BLI_kdtree_free(edit->emitter_field);
		edit->emitter_field= 0;
	}

	psys_free_path_cache(edit->psys, edit);

	MEM_freeN(edit);
}

/************************************************/
/*			Edit Mode Helpers					*/
/************************************************/

int PE_start_edit(PTCacheEdit *edit)
{
	if (edit) {
		edit->edited = 1;
		if (edit->psys)
			edit->psys->flag |= PSYS_EDITED;
		return 1;
	}

	return 0;
}

ParticleEditSettings *PE_settings(Scene *scene)
{
	return scene->toolsettings ? &scene->toolsettings->particle : NULL;
}

static float pe_brush_size_get(const Scene *UNUSED(scene), ParticleBrushData *brush)
{
	// here we can enable unified brush size, needs more work...
	// UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
	// float size = (ups->flag & UNIFIED_PAINT_SIZE) ? ups->size : brush->size;
	
	return brush->size * U.pixelsize;
}


/* always gets at least the first particlesystem even if PSYS_CURRENT flag is not set
 *
 * note: this function runs on poll, therefor it can runs many times a second
 * keep it fast! */
static PTCacheEdit *pe_get_current(Scene *scene, Object *ob, int create)
{
	ParticleEditSettings *pset= PE_settings(scene);
	PTCacheEdit *edit = NULL;
	ListBase pidlist;
	PTCacheID *pid;

	if (pset==NULL || ob==NULL)
		return NULL;

	pset->scene = scene;
	pset->object = ob;

	BKE_ptcache_ids_from_object(&pidlist, ob, NULL, 0);

	/* in the case of only one editable thing, set pset->edittype accordingly */
	if (BLI_listbase_is_single(&pidlist)) {
		pid = pidlist.first;
		switch (pid->type) {
			case PTCACHE_TYPE_PARTICLES:
				pset->edittype = PE_TYPE_PARTICLES;
				break;
			case PTCACHE_TYPE_SOFTBODY:
				pset->edittype = PE_TYPE_SOFTBODY;
				break;
			case PTCACHE_TYPE_CLOTH:
				pset->edittype = PE_TYPE_CLOTH;
				break;
		}
	}

	for (pid=pidlist.first; pid; pid=pid->next) {
		if (pset->edittype == PE_TYPE_PARTICLES && pid->type == PTCACHE_TYPE_PARTICLES) {
			ParticleSystem *psys = pid->calldata;

			if (psys->flag & PSYS_CURRENT) {
				if (psys->part && psys->part->type == PART_HAIR) {
					if (psys->flag & PSYS_HAIR_DYNAMICS && psys->pointcache->flag & PTCACHE_BAKED) {
						if (create && !psys->pointcache->edit)
							PE_create_particle_edit(scene, ob, pid->cache, NULL);
						edit = pid->cache->edit;
					}
					else {
						if (create && !psys->edit && psys->flag & PSYS_HAIR_DONE)
							PE_create_particle_edit(scene, ob, NULL, psys);
						edit = psys->edit;
					}
				}
				else {
					if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit)
						PE_create_particle_edit(scene, ob, pid->cache, psys);
					edit = pid->cache->edit;
				}

				break;
			}
		}
		else if (pset->edittype == PE_TYPE_SOFTBODY && pid->type == PTCACHE_TYPE_SOFTBODY) {
			if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit) {
				pset->flag |= PE_FADE_TIME;
				// NICE TO HAVE but doesn't work: pset->brushtype = PE_BRUSH_COMB;
				PE_create_particle_edit(scene, ob, pid->cache, NULL);
			}
			edit = pid->cache->edit;
			break;
		}
		else if (pset->edittype == PE_TYPE_CLOTH && pid->type == PTCACHE_TYPE_CLOTH) {
			if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit) {
				pset->flag |= PE_FADE_TIME;
				// NICE TO HAVE but doesn't work: pset->brushtype = PE_BRUSH_COMB;
				PE_create_particle_edit(scene, ob, pid->cache, NULL);
			}
			edit = pid->cache->edit;
			break;
		}
	}

	if (edit)
		edit->pid = *pid;

	BLI_freelistN(&pidlist);

	return edit;
}

PTCacheEdit *PE_get_current(Scene *scene, Object *ob)
{
	return pe_get_current(scene, ob, 0);
}

PTCacheEdit *PE_create_current(Scene *scene, Object *ob)
{
	return pe_get_current(scene, ob, 1);
}

void PE_current_changed(Scene *scene, Object *ob)
{
	if (ob->mode == OB_MODE_PARTICLE_EDIT)
		PE_create_current(scene, ob);
}

void PE_hide_keys_time(Scene *scene, PTCacheEdit *edit, float cfra)
{
	ParticleEditSettings *pset=PE_settings(scene);
	POINT_P; KEY_K;


	if (pset->flag & PE_FADE_TIME && pset->selectmode==SCE_SELECT_POINT) {
		LOOP_POINTS {
			LOOP_KEYS {
				if (fabsf(cfra - *key->time) < pset->fade_frames)
					key->flag &= ~PEK_HIDE;
				else {
					key->flag |= PEK_HIDE;
					//key->flag &= ~PEK_SELECT;
				}
			}
		}
	}
	else {
		LOOP_POINTS {
			LOOP_KEYS {
				key->flag &= ~PEK_HIDE;
			}
		}
	}
}

static int pe_x_mirror(Object *ob)
{
	if (ob->type == OB_MESH)
		return (((Mesh *)ob->data)->editflag & ME_EDIT_MIRROR_X);
	
	return 0;
}

/****************** common struct passed to callbacks ******************/

typedef struct PEData {
	ViewContext vc;
	bglMats mats;
	
	Scene *scene;
	Object *ob;
	DerivedMesh *dm;
	PTCacheEdit *edit;
	BVHTreeFromMesh shape_bvh;

	const int *mval;
	rcti *rect;
	float rad;
	float dist;
	float dval;
	int select;

	float *dvec;
	float combfac;
	float pufffac;
	float cutfac;
	float smoothfac;
	float weightfac;
	float growfac;
	int totrekey;

	int invert;
	int tot;
	float vec[3];

	int select_action;
	int select_toggle_action;
} PEData;

static void PE_set_data(bContext *C, PEData *data)
{
	memset(data, 0, sizeof(*data));

	data->scene= CTX_data_scene(C);
	data->ob= CTX_data_active_object(C);
	data->edit= PE_get_current(data->scene, data->ob);
}

static void PE_set_view3d_data(bContext *C, PEData *data)
{
	PE_set_data(C, data);

	view3d_set_viewcontext(C, &data->vc);
	/* note, the object argument means the modelview matrix does not account for the objects matrix, use viewmat rather than (obmat * viewmat) */
	view3d_get_transformation(data->vc.ar, data->vc.rv3d, NULL, &data->mats);

	if (V3D_IS_ZBUF(data->vc.v3d)) {
		if (data->vc.v3d->flag & V3D_INVALID_BACKBUF) {
			/* needed or else the draw matrix can be incorrect */
			view3d_operator_needs_opengl(C);

			ED_view3d_backbuf_validate(&data->vc);
			/* we may need to force an update here by setting the rv3d as dirty
			 * for now it seems ok, but take care!:
			 * rv3d->depths->dirty = 1; */
			ED_view3d_depth_update(data->vc.ar);
		}
	}
}

static bool PE_create_shape_tree(PEData *data, Object *shapeob)
{
	DerivedMesh *dm = shapeob->derivedFinal;
	
	memset(&data->shape_bvh, 0, sizeof(data->shape_bvh));
	
	if (!dm) {
		return false;
	}
	
	return (bvhtree_from_mesh_looptri(&data->shape_bvh, dm, 0.0f, 4, 8) != NULL);
}

static void PE_free_shape_tree(PEData *data)
{
	free_bvhtree_from_mesh(&data->shape_bvh);
}

/*************************** selection utilities *******************************/

static bool key_test_depth(PEData *data, const float co[3], const int screen_co[2])
{
	View3D *v3d= data->vc.v3d;
	ViewDepths *vd = data->vc.rv3d->depths;
	double ux, uy, uz;
	float depth;

	/* nothing to do */
	if (!V3D_IS_ZBUF(v3d))
		return true;

	/* used to calculate here but all callers have  the screen_co already, so pass as arg */
#if 0
	if (ED_view3d_project_int_global(data->vc.ar, co, screen_co,
	                                 V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN | V3D_PROJ_TEST_CLIP_NEAR) != V3D_PROJ_RET_OK)
	{
		return 0;
	}
#endif

	gluProject(co[0], co[1], co[2], data->mats.modelview, data->mats.projection,
	           (GLint *)data->mats.viewport, &ux, &uy, &uz);

	/* check if screen_co is within bounds because brush_cut uses out of screen coords */
	if (screen_co[0] >= 0 && screen_co[0] < vd->w && screen_co[1] >= 0 && screen_co[1] < vd->h) {
		BLI_assert(vd && vd->depths);
		/* we know its not clipped */
		depth = vd->depths[screen_co[1] * vd->w + screen_co[0]];
	}
	else
		return 0;

	if ((float)uz - 0.00001f > depth)
		return 0;
	else
		return 1;
}

static bool key_inside_circle(PEData *data, float rad, const float co[3], float *distance)
{
	float dx, dy, dist;
	int screen_co[2];

	/* TODO, should this check V3D_PROJ_TEST_CLIP_BB too? */
	if (ED_view3d_project_int_global(data->vc.ar, co, screen_co, V3D_PROJ_TEST_CLIP_WIN) != V3D_PROJ_RET_OK) {
		return 0;
	}

	dx= data->mval[0] - screen_co[0];
	dy= data->mval[1] - screen_co[1];
	dist = sqrtf(dx * dx + dy * dy);

	if (dist > rad)
		return 0;

	if (key_test_depth(data, co, screen_co)) {
		if (distance)
			*distance=dist;

		return 1;
	}
	
	return 0;
}

static bool key_inside_rect(PEData *data, const float co[3])
{
	int screen_co[2];

	if (ED_view3d_project_int_global(data->vc.ar, co, screen_co, V3D_PROJ_TEST_CLIP_WIN) != V3D_PROJ_RET_OK) {
		return 0;
	}

	if (screen_co[0] > data->rect->xmin && screen_co[0] < data->rect->xmax &&
	    screen_co[1] > data->rect->ymin && screen_co[1] < data->rect->ymax)
	{
		return key_test_depth(data, co, screen_co);
	}

	return 0;
}

static bool key_inside_test(PEData *data, const float co[3])
{
	if (data->mval)
		return key_inside_circle(data, data->rad, co, NULL);
	else
		return key_inside_rect(data, co);
}

static bool point_is_selected(PTCacheEditPoint *point)
{
	KEY_K;

	if (point->flag & PEP_HIDE)
		return 0;

	LOOP_SELECTED_KEYS {
		return 1;
	}
	
	return 0;
}

/*************************** iterators *******************************/

typedef void (*ForPointFunc)(PEData *data, int point_index);
typedef void (*ForKeyFunc)(PEData *data, int point_index, int key_index);
typedef void (*ForKeyMatFunc)(PEData *data, float mat[4][4], float imat[4][4], int point_index, int key_index, PTCacheEditKey *key);

static void for_mouse_hit_keys(PEData *data, ForKeyFunc func, int nearest)
{
	ParticleEditSettings *pset= PE_settings(data->scene);
	PTCacheEdit *edit= data->edit;
	POINT_P; KEY_K;
	int nearest_point, nearest_key;
	float dist= data->rad;

	/* in path select mode we have no keys */
	if (pset->selectmode==SCE_SELECT_PATH)
		return;

	nearest_point= -1;
	nearest_key= -1;

	LOOP_VISIBLE_POINTS {
		if (pset->selectmode == SCE_SELECT_END) {
			if (point->totkey) {
				/* only do end keys */
				key= point->keys + point->totkey-1;

				if (nearest) {
					if (key_inside_circle(data, dist, KEY_WCO, &dist)) {
						nearest_point= p;
						nearest_key= point->totkey-1;
					}
				}
				else if (key_inside_test(data, KEY_WCO))
					func(data, p, point->totkey-1);
			}
		}
		else {
			/* do all keys */
			LOOP_VISIBLE_KEYS {
				if (nearest) {
					if (key_inside_circle(data, dist, KEY_WCO, &dist)) {
						nearest_point= p;
						nearest_key= k;
					}
				}
				else if (key_inside_test(data, KEY_WCO))
					func(data, p, k);
			}
		}
	}

	/* do nearest only */
	if (nearest && nearest_point > -1)
		func(data, nearest_point, nearest_key);
}

static void foreach_mouse_hit_point(PEData *data, ForPointFunc func, int selected)
{
	ParticleEditSettings *pset= PE_settings(data->scene);
	PTCacheEdit *edit= data->edit;
	POINT_P; KEY_K;

	/* all is selected in path mode */
	if (pset->selectmode==SCE_SELECT_PATH)
		selected=0;

	LOOP_VISIBLE_POINTS {
		if (pset->selectmode==SCE_SELECT_END) {
			if (point->totkey) {
				/* only do end keys */
				key= point->keys + point->totkey - 1;

				if (selected==0 || key->flag & PEK_SELECT)
					if (key_inside_circle(data, data->rad, KEY_WCO, &data->dist))
						func(data, p);
			}
		}
		else {
			/* do all keys */
			LOOP_VISIBLE_KEYS {
				if (selected==0 || key->flag & PEK_SELECT) {
					if (key_inside_circle(data, data->rad, KEY_WCO, &data->dist)) {
						func(data, p);
						break;
					}
				}
			}
		}
	}
}

static void foreach_mouse_hit_key(PEData *data, ForKeyMatFunc func, int selected)
{
	PTCacheEdit *edit = data->edit;
	ParticleSystem *psys = edit->psys;
	ParticleSystemModifierData *psmd = NULL;
	ParticleEditSettings *pset= PE_settings(data->scene);
	POINT_P; KEY_K;
	float mat[4][4], imat[4][4];

	unit_m4(mat);
	unit_m4(imat);

	if (edit->psys)
		psmd= psys_get_modifier(data->ob, edit->psys);

	/* all is selected in path mode */
	if (pset->selectmode==SCE_SELECT_PATH)
		selected= 0;

	LOOP_VISIBLE_POINTS {
		if (pset->selectmode==SCE_SELECT_END) {
			if (point->totkey) {
				/* only do end keys */
				key= point->keys + point->totkey-1;

				if (selected==0 || key->flag & PEK_SELECT) {
					if (key_inside_circle(data, data->rad, KEY_WCO, &data->dist)) {
						if (edit->psys && !(edit->psys->flag & PSYS_GLOBAL_HAIR)) {
							psys_mat_hair_to_global(data->ob, psmd->dm_final, psys->part->from, psys->particles + p, mat);
							invert_m4_m4(imat, mat);
						}

						func(data, mat, imat, p, point->totkey-1, key);
					}
				}
			}
		}
		else {
			/* do all keys */
			LOOP_VISIBLE_KEYS {
				if (selected==0 || key->flag & PEK_SELECT) {
					if (key_inside_circle(data, data->rad, KEY_WCO, &data->dist)) {
						if (edit->psys && !(edit->psys->flag & PSYS_GLOBAL_HAIR)) {
							psys_mat_hair_to_global(data->ob, psmd->dm_final, psys->part->from, psys->particles + p, mat);
							invert_m4_m4(imat, mat);
						}

						func(data, mat, imat, p, k, key);
					}
				}
			}
		}
	}
}

static void foreach_selected_point(PEData *data, ForPointFunc func)
{
	PTCacheEdit *edit = data->edit;
	POINT_P;

	LOOP_SELECTED_POINTS {
		func(data, p);
	}
}

static void foreach_selected_key(PEData *data, ForKeyFunc func)
{
	PTCacheEdit *edit = data->edit;
	POINT_P; KEY_K;

	LOOP_VISIBLE_POINTS {
		LOOP_SELECTED_KEYS {
			func(data, p, k);
		}
	}
}

static void foreach_point(PEData *data, ForPointFunc func)
{
	PTCacheEdit *edit = data->edit;
	POINT_P;

	LOOP_POINTS {
		func(data, p);
	}
}

static int count_selected_keys(Scene *scene, PTCacheEdit *edit)
{
	ParticleEditSettings *pset= PE_settings(scene);
	POINT_P; KEY_K;
	int sel= 0;

	LOOP_VISIBLE_POINTS {
		if (pset->selectmode==SCE_SELECT_POINT) {
			LOOP_SELECTED_KEYS {
				sel++;
			}
		}
		else if (pset->selectmode==SCE_SELECT_END) {
			if (point->totkey) {
				key = point->keys + point->totkey - 1;
				if (key->flag & PEK_SELECT)
					sel++;
			}
		}
	}

	return sel;
}

/************************************************/
/*			Particle Edit Mirroring				*/
/************************************************/

static void PE_update_mirror_cache(Object *ob, ParticleSystem *psys)
{
	PTCacheEdit *edit;
	ParticleSystemModifierData *psmd;
	KDTree *tree;
	KDTreeNearest nearest;
	HairKey *key;
	PARTICLE_P;
	float mat[4][4], co[3];
	int index, totpart;

	edit= psys->edit;
	psmd= psys_get_modifier(ob, psys);
	totpart= psys->totpart;

	if (!psmd->dm_final)
		return;

	tree= BLI_kdtree_new(totpart);

	/* insert particles into kd tree */
	LOOP_PARTICLES {
		key = pa->hair;
		psys_mat_hair_to_orco(ob, psmd->dm_final, psys->part->from, pa, mat);
		copy_v3_v3(co, key->co);
		mul_m4_v3(mat, co);
		BLI_kdtree_insert(tree, p, co);
	}

	BLI_kdtree_balance(tree);

	/* lookup particles and set in mirror cache */
	if (!edit->mirror_cache)
		edit->mirror_cache= MEM_callocN(sizeof(int)*totpart, "PE mirror cache");
	
	LOOP_PARTICLES {
		key = pa->hair;
		psys_mat_hair_to_orco(ob, psmd->dm_final, psys->part->from, pa, mat);
		copy_v3_v3(co, key->co);
		mul_m4_v3(mat, co);
		co[0] = -co[0];

		index= BLI_kdtree_find_nearest(tree, co, &nearest);

		/* this needs a custom threshold still, duplicated for editmode mirror */
		if (index != -1 && index != p && (nearest.dist <= 0.0002f))
			edit->mirror_cache[p] = index;
		else
			edit->mirror_cache[p] = -1;
	}

	/* make sure mirrors are in two directions */
	LOOP_PARTICLES {
		if (edit->mirror_cache[p]) {
			index= edit->mirror_cache[p];
			if (edit->mirror_cache[index] != p)
				edit->mirror_cache[p] = -1;
		}
	}

	BLI_kdtree_free(tree);
}

static void PE_mirror_particle(Object *ob, DerivedMesh *dm, ParticleSystem *psys, ParticleData *pa, ParticleData *mpa)
{
	HairKey *hkey, *mhkey;
	PTCacheEditPoint *point, *mpoint;
	PTCacheEditKey *key, *mkey;
	PTCacheEdit *edit;
	float mat[4][4], mmat[4][4], immat[4][4];
	int i, mi, k;

	edit= psys->edit;
	i= pa - psys->particles;

	/* find mirrored particle if needed */
	if (!mpa) {
		if (!edit->mirror_cache)
			PE_update_mirror_cache(ob, psys);
		
		if (!edit->mirror_cache)
			return; /* something went wrong! */

		mi= edit->mirror_cache[i];
		if (mi == -1)
			return;
		mpa= psys->particles + mi;
	}
	else
		mi= mpa - psys->particles;

	point = edit->points + i;
	mpoint = edit->points + mi;

	/* make sure they have the same amount of keys */
	if (pa->totkey != mpa->totkey) {
		if (mpa->hair) MEM_freeN(mpa->hair);
		if (mpoint->keys) MEM_freeN(mpoint->keys);

		mpa->hair= MEM_dupallocN(pa->hair);
		mpa->totkey= pa->totkey;
		mpoint->keys= MEM_dupallocN(point->keys);
		mpoint->totkey= point->totkey;

		mhkey= mpa->hair;
		mkey= mpoint->keys;
		for (k=0; k<mpa->totkey; k++, mkey++, mhkey++) {
			mkey->co= mhkey->co;
			mkey->time= &mhkey->time;
			mkey->flag &= ~PEK_SELECT;
		}
	}

	/* mirror positions and tags */
	psys_mat_hair_to_orco(ob, dm, psys->part->from, pa, mat);
	psys_mat_hair_to_orco(ob, dm, psys->part->from, mpa, mmat);
	invert_m4_m4(immat, mmat);

	hkey=pa->hair;
	mhkey=mpa->hair;
	key= point->keys;
	mkey= mpoint->keys;
	for (k=0; k<pa->totkey; k++, hkey++, mhkey++, key++, mkey++) {
		copy_v3_v3(mhkey->co, hkey->co);
		mul_m4_v3(mat, mhkey->co);
		mhkey->co[0] = -mhkey->co[0];
		mul_m4_v3(immat, mhkey->co);

		if (key->flag & PEK_TAG)
			mkey->flag |= PEK_TAG;

		mkey->length = key->length;
	}

	if (point->flag & PEP_TAG)
		mpoint->flag |= PEP_TAG;
	if (point->flag & PEP_EDIT_RECALC)
		mpoint->flag |= PEP_EDIT_RECALC;
}

static void PE_apply_mirror(Object *ob, ParticleSystem *psys)
{
	PTCacheEdit *edit;
	ParticleSystemModifierData *psmd;
	POINT_P;

	if (!psys)
		return;

	edit= psys->edit;
	psmd= psys_get_modifier(ob, psys);

	if (!psmd->dm_final)
		return;

	if (!edit->mirror_cache)
		PE_update_mirror_cache(ob, psys);

	if (!edit->mirror_cache)
		return; /* something went wrong */

	/* we delay settings the PARS_EDIT_RECALC for mirrored particles
	 * to avoid doing mirror twice */
	LOOP_POINTS {
		if (point->flag & PEP_EDIT_RECALC) {
			PE_mirror_particle(ob, psmd->dm_final, psys, psys->particles + p, NULL);

			if (edit->mirror_cache[p] != -1)
				edit->points[edit->mirror_cache[p]].flag &= ~PEP_EDIT_RECALC;
		}
	}

	LOOP_POINTS {
		if (point->flag & PEP_EDIT_RECALC)
			if (edit->mirror_cache[p] != -1)
				edit->points[edit->mirror_cache[p]].flag |= PEP_EDIT_RECALC;
	}
}

/************************************************/
/*			Edit Calculation					*/
/************************************************/
/* tries to stop edited particles from going through the emitter's surface */
static void pe_deflect_emitter(Scene *scene, Object *ob, PTCacheEdit *edit)
{
	ParticleEditSettings *pset= PE_settings(scene);
	ParticleSystem *psys;
	ParticleSystemModifierData *psmd;
	POINT_P; KEY_K;
	int index;
	float *vec, *nor, dvec[3], dot, dist_1st=0.0f;
	float hairimat[4][4], hairmat[4][4];
	const float dist = ED_view3d_select_dist_px() * 0.01f;

	if (edit==NULL || edit->psys==NULL || (pset->flag & PE_DEFLECT_EMITTER)==0 || (edit->psys->flag & PSYS_GLOBAL_HAIR))
		return;

	psys = edit->psys;
	psmd = psys_get_modifier(ob, psys);

	if (!psmd->dm_final)
		return;

	LOOP_EDITED_POINTS {
		psys_mat_hair_to_object(ob, psmd->dm_final, psys->part->from, psys->particles + p, hairmat);
	
		LOOP_KEYS {
			mul_m4_v3(hairmat, key->co);
		}

		LOOP_KEYS {
			if (k==0) {
				dist_1st = len_v3v3((key+1)->co, key->co);
				dist_1st *= dist * pset->emitterdist;
			}
			else {
				index= BLI_kdtree_find_nearest(edit->emitter_field, key->co, NULL);
				
				vec=edit->emitter_cosnos +index*6;
				nor=vec+3;

				sub_v3_v3v3(dvec, key->co, vec);

				dot=dot_v3v3(dvec, nor);
				copy_v3_v3(dvec, nor);

				if (dot>0.0f) {
					if (dot<dist_1st) {
						normalize_v3(dvec);
						mul_v3_fl(dvec, dist_1st-dot);
						add_v3_v3(key->co, dvec);
					}
				}
				else {
					normalize_v3(dvec);
					mul_v3_fl(dvec, dist_1st-dot);
					add_v3_v3(key->co, dvec);
				}
				if (k==1)
					dist_1st*=1.3333f;
			}
		}
		
		invert_m4_m4(hairimat, hairmat);

		LOOP_KEYS {
			mul_m4_v3(hairimat, key->co);
		}
	}
}
/* force set distances between neighboring keys */
static void PE_apply_lengths(Scene *scene, PTCacheEdit *edit)
{
	
	ParticleEditSettings *pset=PE_settings(scene);
	POINT_P; KEY_K;
	float dv1[3];

	if (edit==0 || (pset->flag & PE_KEEP_LENGTHS)==0)
		return;

	if (edit->psys && edit->psys->flag & PSYS_GLOBAL_HAIR)
		return;

	LOOP_EDITED_POINTS {
		LOOP_KEYS {
			if (k) {
				sub_v3_v3v3(dv1, key->co, (key - 1)->co);
				normalize_v3(dv1);
				mul_v3_fl(dv1, (key - 1)->length);
				add_v3_v3v3(key->co, (key - 1)->co, dv1);
			}
		}
	}
}
/* try to find a nice solution to keep distances between neighboring keys */
static void pe_iterate_lengths(Scene *scene, PTCacheEdit *edit)
{
	ParticleEditSettings *pset=PE_settings(scene);
	POINT_P;
	PTCacheEditKey *key;
	int j, k;
	float tlen;
	float dv0[3] = {0.0f, 0.0f, 0.0f};
	float dv1[3] = {0.0f, 0.0f, 0.0f};
	float dv2[3] = {0.0f, 0.0f, 0.0f};

	if (edit==0 || (pset->flag & PE_KEEP_LENGTHS)==0)
		return;

	if (edit->psys && edit->psys->flag & PSYS_GLOBAL_HAIR)
		return;

	LOOP_EDITED_POINTS {
		for (j=1; j<point->totkey; j++) {
			float mul= 1.0f / (float)point->totkey;

			if (pset->flag & PE_LOCK_FIRST) {
				key= point->keys + 1;
				k= 1;
				dv1[0] = dv1[1] = dv1[2] = 0.0;
			}
			else {
				key= point->keys;
				k= 0;
				dv0[0] = dv0[1] = dv0[2] = 0.0;
			}

			for (; k<point->totkey; k++, key++) {
				if (k) {
					sub_v3_v3v3(dv0, (key - 1)->co, key->co);
					tlen= normalize_v3(dv0);
					mul_v3_fl(dv0, (mul * (tlen - (key - 1)->length)));
				}

				if (k < point->totkey - 1) {
					sub_v3_v3v3(dv2, (key + 1)->co, key->co);
					tlen= normalize_v3(dv2);
					mul_v3_fl(dv2, mul * (tlen - key->length));
				}

				if (k) {
					add_v3_v3((key-1)->co, dv1);
				}

				add_v3_v3v3(dv1, dv0, dv2);
			}
		}
	}
}
/* set current distances to be kept between neighbouting keys */
void recalc_lengths(PTCacheEdit *edit)
{
	POINT_P; KEY_K;

	if (edit==0)
		return;

	LOOP_EDITED_POINTS {
		key= point->keys;
		for (k=0; k<point->totkey-1; k++, key++) {
			key->length= len_v3v3(key->co, (key + 1)->co);
		}
	}
}

/* calculate a tree for finding nearest emitter's vertice */
void recalc_emitter_field(Object *ob, ParticleSystem *psys)
{
	DerivedMesh *dm=psys_get_modifier(ob, psys)->dm_final;
	PTCacheEdit *edit= psys->edit;
	float *vec, *nor;
	int i, totface /*, totvert*/;

	if (!dm)
		return;

	if (edit->emitter_cosnos)
		MEM_freeN(edit->emitter_cosnos);

	BLI_kdtree_free(edit->emitter_field);

	totface=dm->getNumTessFaces(dm);
	/*totvert=dm->getNumVerts(dm);*/ /*UNSUED*/

	edit->emitter_cosnos=MEM_callocN(totface*6*sizeof(float), "emitter cosnos");

	edit->emitter_field= BLI_kdtree_new(totface);

	vec=edit->emitter_cosnos;
	nor=vec+3;

	for (i=0; i<totface; i++, vec+=6, nor+=6) {
		MFace *mface=dm->getTessFaceData(dm, i, CD_MFACE);
		MVert *mvert;

		mvert=dm->getVertData(dm, mface->v1, CD_MVERT);
		copy_v3_v3(vec, mvert->co);
		VECCOPY(nor, mvert->no);

		mvert=dm->getVertData(dm, mface->v2, CD_MVERT);
		add_v3_v3v3(vec, vec, mvert->co);
		VECADD(nor, nor, mvert->no);

		mvert=dm->getVertData(dm, mface->v3, CD_MVERT);
		add_v3_v3v3(vec, vec, mvert->co);
		VECADD(nor, nor, mvert->no);

		if (mface->v4) {
			mvert=dm->getVertData(dm, mface->v4, CD_MVERT);
			add_v3_v3v3(vec, vec, mvert->co);
			VECADD(nor, nor, mvert->no);
			
			mul_v3_fl(vec, 0.25);
		}
		else
			mul_v3_fl(vec, 1.0f / 3.0f);

		normalize_v3(nor);

		BLI_kdtree_insert(edit->emitter_field, i, vec);
	}

	BLI_kdtree_balance(edit->emitter_field);
}

static void PE_update_selection(Scene *scene, Object *ob, int useflag)
{
	PTCacheEdit *edit= PE_get_current(scene, ob);
	HairKey *hkey;
	POINT_P; KEY_K;

	/* flag all particles to be updated if not using flag */
	if (!useflag)
		LOOP_POINTS
			point->flag |= PEP_EDIT_RECALC;

	/* flush edit key flag to hair key flag to preserve selection 
	 * on save */
	if (edit->psys) LOOP_POINTS {
		hkey = edit->psys->particles[p].hair;
		LOOP_KEYS {
			hkey->editflag= key->flag;
			hkey++;
		}
	}

	psys_cache_edit_paths(scene, ob, edit, CFRA, G.is_rendering);


	/* disable update flag */
	LOOP_POINTS
		point->flag &= ~PEP_EDIT_RECALC;
}

void update_world_cos(Object *ob, PTCacheEdit *edit)
{
	ParticleSystem *psys = edit->psys;
	ParticleSystemModifierData *psmd= psys_get_modifier(ob, psys);
	POINT_P; KEY_K;
	float hairmat[4][4];

	if (psys==0 || psys->edit==0 || psmd->dm_final==NULL)
		return;

	LOOP_POINTS {
		if (!(psys->flag & PSYS_GLOBAL_HAIR))
			psys_mat_hair_to_global(ob, psmd->dm_final, psys->part->from, psys->particles+p, hairmat);

		LOOP_KEYS {
			copy_v3_v3(key->world_co, key->co);
			if (!(psys->flag & PSYS_GLOBAL_HAIR))
				mul_m4_v3(hairmat, key->world_co);
		}
	}
}
static void update_velocities(PTCacheEdit *edit)
{
	/*TODO: get frs_sec properly */
	float vec1[3], vec2[3], frs_sec, dfra;
	POINT_P; KEY_K;

	/* hair doesn't use velocities */
	if (edit->psys || !edit->points || !edit->points->keys->vel)
		return;

	frs_sec = edit->pid.flag & PTCACHE_VEL_PER_SEC ? 25.0f : 1.0f;

	LOOP_EDITED_POINTS {
		LOOP_KEYS {
			if (k==0) {
				dfra = *(key+1)->time - *key->time;

				if (dfra <= 0.0f)
					continue;

				sub_v3_v3v3(key->vel, (key+1)->co, key->co);

				if (point->totkey>2) {
					sub_v3_v3v3(vec1, (key+1)->co, (key+2)->co);
					project_v3_v3v3(vec2, vec1, key->vel);
					sub_v3_v3v3(vec2, vec1, vec2);
					madd_v3_v3fl(key->vel, vec2, 0.5f);
				}
			}
			else if (k==point->totkey-1) {
				dfra = *key->time - *(key-1)->time;

				if (dfra <= 0.0f)
					continue;

				sub_v3_v3v3(key->vel, key->co, (key-1)->co);

				if (point->totkey>2) {
					sub_v3_v3v3(vec1, (key-2)->co, (key-1)->co);
					project_v3_v3v3(vec2, vec1, key->vel);
					sub_v3_v3v3(vec2, vec1, vec2);
					madd_v3_v3fl(key->vel, vec2, 0.5f);
				}
			}
			else {
				dfra = *(key+1)->time - *(key-1)->time;
				
				if (dfra <= 0.0f)
					continue;

				sub_v3_v3v3(key->vel, (key+1)->co, (key-1)->co);
			}
			mul_v3_fl(key->vel, frs_sec/dfra);
		}
	}
}

void PE_update_object(Scene *scene, Object *ob, int useflag)
{
	/* use this to do partial particle updates, not usable when adding or
	 * removing, then a full redo is necessary and calling this may crash */
	ParticleEditSettings *pset= PE_settings(scene);
	PTCacheEdit *edit = PE_get_current(scene, ob);
	POINT_P;

	if (!edit)
		return;

	/* flag all particles to be updated if not using flag */
	if (!useflag)
		LOOP_POINTS {
			point->flag |= PEP_EDIT_RECALC;
		}

	/* do post process on particle edit keys */
	pe_iterate_lengths(scene, edit);
	pe_deflect_emitter(scene, ob, edit);
	PE_apply_lengths(scene, edit);
	if (pe_x_mirror(ob))
		PE_apply_mirror(ob, edit->psys);
	if (edit->psys)
		update_world_cos(ob, edit);
	if (pset->flag & PE_AUTO_VELOCITY)
		update_velocities(edit);
	PE_hide_keys_time(scene, edit, CFRA);

	/* regenerate path caches */
	psys_cache_edit_paths(scene, ob, edit, CFRA, G.is_rendering);

	/* disable update flag */
	LOOP_POINTS {
		point->flag &= ~PEP_EDIT_RECALC;
	}

	if (edit->psys)
		edit->psys->flag &= ~PSYS_HAIR_UPDATED;
}

/************************************************/
/*			Edit Selections						*/
/************************************************/

/*-----selection callbacks-----*/

static void select_key(PEData *data, int point_index, int key_index)
{
	PTCacheEdit *edit = data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	PTCacheEditKey *key = point->keys + key_index;

	if (data->select)
		key->flag |= PEK_SELECT;
	else
		key->flag &= ~PEK_SELECT;

	point->flag |= PEP_EDIT_RECALC;
}

static void select_keys(PEData *data, int point_index, int UNUSED(key_index))
{
	PTCacheEdit *edit = data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	KEY_K;

	LOOP_KEYS {
		if (data->select)
			key->flag |= PEK_SELECT;
		else
			key->flag &= ~PEK_SELECT;
	}

	point->flag |= PEP_EDIT_RECALC;
}

static void extend_key_select(PEData *data, int point_index, int key_index)
{
	PTCacheEdit *edit = data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	PTCacheEditKey *key = point->keys + key_index;

	key->flag |= PEK_SELECT;
	point->flag |= PEP_EDIT_RECALC;
}

static void deselect_key_select(PEData *data, int point_index, int key_index)
{
	PTCacheEdit *edit = data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	PTCacheEditKey *key = point->keys + key_index;

	key->flag &= ~PEK_SELECT;
	point->flag |= PEP_EDIT_RECALC;
}

static void toggle_key_select(PEData *data, int point_index, int key_index)
{
	PTCacheEdit *edit = data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	PTCacheEditKey *key = point->keys + key_index;

	key->flag ^= PEK_SELECT;
	point->flag |= PEP_EDIT_RECALC;
}

/************************ de select all operator ************************/

static void select_action_apply(PTCacheEditPoint *point, PTCacheEditKey *key, int action)
{
	switch (action) {
	case SEL_SELECT:
		if ((key->flag & PEK_SELECT) == 0) {
			key->flag |= PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC;
		}
		break;
	case SEL_DESELECT:
		if (key->flag & PEK_SELECT) {
			key->flag &= ~PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC;
		}
		break;
	case SEL_INVERT:
		if ((key->flag & PEK_SELECT) == 0) {
			key->flag |= PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC;
		}
		else {
			key->flag &= ~PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC;
		}
		break;
	}
}

static int pe_select_all_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	POINT_P; KEY_K;
	int action = RNA_enum_get(op->ptr, "action");

	if (action == SEL_TOGGLE) {
		action = SEL_SELECT;
		LOOP_VISIBLE_POINTS {
			LOOP_SELECTED_KEYS {
				action = SEL_DESELECT;
				break;
			}

			if (action == SEL_DESELECT)
				break;
		}
	}

	LOOP_VISIBLE_POINTS {
		LOOP_VISIBLE_KEYS {
			select_action_apply(point, key, action);
		}
	}

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_all(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "(De)select All";
	ot->idname = "PARTICLE_OT_select_all";
	ot->description = "(De)select all particles' keys";
	
	/* api callbacks */
	ot->exec = pe_select_all_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	WM_operator_properties_select_all(ot);
}

/************************ pick select operator ************************/

int PE_mouse_particles(bContext *C, const int mval[2], bool extend, bool deselect, bool toggle)
{
	PEData data;
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	POINT_P; KEY_K;
	
	if (!PE_start_edit(edit))
		return OPERATOR_CANCELLED;

	if (!extend && !deselect && !toggle) {
		LOOP_VISIBLE_POINTS {
			LOOP_SELECTED_KEYS {
				key->flag &= ~PEK_SELECT;
				point->flag |= PEP_EDIT_RECALC;
			}
		}
	}

	PE_set_view3d_data(C, &data);
	data.mval= mval;
	data.rad = ED_view3d_select_dist_px();

	/* 1 = nearest only */
	if (extend)
		for_mouse_hit_keys(&data, extend_key_select, 1);
	else if (deselect)
		for_mouse_hit_keys(&data, deselect_key_select, 1);
	else
		for_mouse_hit_keys(&data, toggle_key_select, 1);

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

/************************ select root operator ************************/

static void select_root(PEData *data, int point_index)
{
	PTCacheEditPoint *point = data->edit->points + point_index;
	PTCacheEditKey *key = point->keys;

	if (point->flag & PEP_HIDE)
		return;
	
	if (data->select_action != SEL_TOGGLE)
		select_action_apply(point, key, data->select_action);
	else if (key->flag & PEK_SELECT)
		data->select_toggle_action = SEL_DESELECT;
}

static int select_roots_exec(bContext *C, wmOperator *op)
{
	PEData data;
	int action = RNA_enum_get(op->ptr, "action");

	PE_set_data(C, &data);

	if (action == SEL_TOGGLE) {
		data.select_action = SEL_TOGGLE;
		data.select_toggle_action = SEL_SELECT;

		foreach_point(&data, select_root);

		action = data.select_toggle_action;
	}

	data.select_action = action;
	foreach_point(&data, select_root);

	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_roots(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Roots";
	ot->idname = "PARTICLE_OT_select_roots";
	ot->description = "Select roots of all visible particles";
	
	/* api callbacks */
	ot->exec = select_roots_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	WM_operator_properties_select_action(ot, SEL_SELECT);
}

/************************ select tip operator ************************/

static void select_tip(PEData *data, int point_index)
{
	PTCacheEditPoint *point = data->edit->points + point_index;
	PTCacheEditKey *key;

	if (point->totkey == 0) {
		return;
	}

	key = &point->keys[point->totkey - 1];
	
	if (point->flag & PEP_HIDE)
		return;
	
	if (data->select_action != SEL_TOGGLE)
		select_action_apply(point, key, data->select_action);
	else if (key->flag & PEK_SELECT)
		data->select_toggle_action = SEL_DESELECT;
}

static int select_tips_exec(bContext *C, wmOperator *op)
{
	PEData data;
	int action = RNA_enum_get(op->ptr, "action");

	PE_set_data(C, &data);

	if (action == SEL_TOGGLE) {
		data.select_action = SEL_TOGGLE;
		data.select_toggle_action = SEL_SELECT;

		foreach_point(&data, select_tip);

		action = data.select_toggle_action;
	}

	data.select_action = action;
	foreach_point(&data, select_tip);

	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_tips(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Tips";
	ot->idname = "PARTICLE_OT_select_tips";
	ot->description = "Select tips of all visible particles";

	/* api callbacks */
	ot->exec = select_tips_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	WM_operator_properties_select_action(ot, SEL_SELECT);
}

/*********************** select random operator ************************/

enum { RAN_HAIR, RAN_POINTS };

static EnumPropertyItem select_random_type_items[] = {
	{RAN_HAIR, "HAIR", 0, "Hair", ""},
	{RAN_POINTS, "POINTS", 0, "Points", ""},
	{0, NULL, 0, NULL, NULL}
};

static int select_random_exec(bContext *C, wmOperator *op)
{
	PEData data;
	int type;
	Scene *scene;
	Object *ob;

	/* used by LOOP_VISIBLE_POINTS, LOOP_VISIBLE_KEYS and LOOP_KEYS */
	PTCacheEdit *edit;
	PTCacheEditPoint *point;
	PTCacheEditKey *key;
	int p;
	int k;

	const float randfac = RNA_float_get(op->ptr, "percent") / 100.0f;
	const int seed = WM_operator_properties_select_random_seed_increment_get(op);
	const bool select = (RNA_enum_get(op->ptr, "action") == SEL_SELECT);
	RNG *rng;

	type = RNA_enum_get(op->ptr, "type");

	PE_set_data(C, &data);
	data.select_action = SEL_SELECT;
	scene = CTX_data_scene(C);
	ob = CTX_data_active_object(C);
	edit = PE_get_current(scene, ob);

	rng = BLI_rng_new_srandom(seed);

	switch (type) {
		case RAN_HAIR:
			LOOP_VISIBLE_POINTS {
				int flag = ((BLI_rng_get_float(rng) < randfac) == select) ? SEL_SELECT : SEL_DESELECT;
				LOOP_KEYS {
					select_action_apply (point, key, flag);
				}
			}
			break;
		case RAN_POINTS:
			LOOP_VISIBLE_POINTS {
				LOOP_VISIBLE_KEYS {
					int flag = ((BLI_rng_get_float(rng) < randfac) == select) ? SEL_SELECT : SEL_DESELECT;
					select_action_apply (point, key, flag);
				}
			}
			break;
	}

	BLI_rng_free(rng);

	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_random(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Random";
	ot->idname = "PARTICLE_OT_select_random";
	ot->description = "Select a randomly distributed set of hair or points";

	/* api callbacks */
	ot->exec = select_random_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	WM_operator_properties_select_random(ot);
	ot->prop = RNA_def_enum (ot->srna, "type", select_random_type_items, RAN_HAIR,
	                         "Type", "Select either hair or points");
}

/************************ select linked operator ************************/

static int select_linked_exec(bContext *C, wmOperator *op)
{
	PEData data;
	int mval[2];
	int location[2];

	RNA_int_get_array(op->ptr, "location", location);
	mval[0] = location[0];
	mval[1] = location[1];

	PE_set_view3d_data(C, &data);
	data.mval= mval;
	data.rad=75.0f;
	data.select= !RNA_boolean_get(op->ptr, "deselect");

	for_mouse_hit_keys(&data, select_keys, 1);  /* nearest only */
	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

static int select_linked_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
	RNA_int_set_array(op->ptr, "location", event->mval);
	return select_linked_exec(C, op);
}

void PARTICLE_OT_select_linked(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Linked";
	ot->idname = "PARTICLE_OT_select_linked";
	ot->description = "Select nearest particle from mouse pointer";
	
	/* api callbacks */
	ot->exec = select_linked_exec;
	ot->invoke = select_linked_invoke;
	ot->poll = PE_poll_view3d;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	RNA_def_boolean(ot->srna, "deselect", 0, "Deselect", "Deselect linked keys rather than selecting them");
	RNA_def_int_vector(ot->srna, "location", 2, NULL, 0, INT_MAX, "Location", "", 0, 16384);
}

/************************ border select operator ************************/
void PE_deselect_all_visible(PTCacheEdit *edit)
{
	POINT_P; KEY_K;

	LOOP_VISIBLE_POINTS {
		LOOP_SELECTED_KEYS {
			key->flag &= ~PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC;
		}
	}
}

int PE_border_select(bContext *C, rcti *rect, bool select, bool extend)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	PEData data;

	if (!PE_start_edit(edit))
		return OPERATOR_CANCELLED;

	if (extend == 0 && select)
		PE_deselect_all_visible(edit);

	PE_set_view3d_data(C, &data);
	data.rect= rect;
	data.select= select;

	for_mouse_hit_keys(&data, select_key, 0);

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

/************************ circle select operator ************************/

int PE_circle_select(bContext *C, int selecting, const int mval[2], float rad)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	PEData data;

	if (!PE_start_edit(edit))
		return OPERATOR_FINISHED;

	PE_set_view3d_data(C, &data);
	data.mval= mval;
	data.rad= rad;
	data.select= selecting;

	for_mouse_hit_keys(&data, select_key, 0);

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

/************************ lasso select operator ************************/

int PE_lasso_select(bContext *C, const int mcords[][2], const short moves, bool extend, bool select)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	ARegion *ar= CTX_wm_region(C);
	ParticleEditSettings *pset= PE_settings(scene);
	PTCacheEdit *edit = PE_get_current(scene, ob);
	ParticleSystem *psys = edit->psys;
	ParticleSystemModifierData *psmd = psys_get_modifier(ob, psys);
	POINT_P; KEY_K;
	float co[3], mat[4][4];
	int screen_co[2];

	PEData data;

	unit_m4(mat);

	if (!PE_start_edit(edit))
		return OPERATOR_CANCELLED;

	if (extend == 0 && select)
		PE_deselect_all_visible(edit);

	/* only for depths */
	PE_set_view3d_data(C, &data);

	LOOP_VISIBLE_POINTS {
		if (edit->psys && !(psys->flag & PSYS_GLOBAL_HAIR))
			psys_mat_hair_to_global(ob, psmd->dm_final, psys->part->from, psys->particles + p, mat);

		if (pset->selectmode==SCE_SELECT_POINT) {
			LOOP_KEYS {
				copy_v3_v3(co, key->co);
				mul_m4_v3(mat, co);
				if ((ED_view3d_project_int_global(ar, co, screen_co, V3D_PROJ_TEST_CLIP_WIN) == V3D_PROJ_RET_OK) &&
				    BLI_lasso_is_point_inside(mcords, moves, screen_co[0], screen_co[1], IS_CLIPPED) &&
				    key_test_depth(&data, co, screen_co))
				{
					if (select) {
						if (!(key->flag & PEK_SELECT)) {
							key->flag |= PEK_SELECT;
							point->flag |= PEP_EDIT_RECALC;
						}
					}
					else {
						if (key->flag & PEK_SELECT) {
							key->flag &= ~PEK_SELECT;
							point->flag |= PEP_EDIT_RECALC;
						}
					}
				}
			}
		}
		else if (pset->selectmode==SCE_SELECT_END) {
			if (point->totkey) {
				key= point->keys + point->totkey - 1;

				copy_v3_v3(co, key->co);
				mul_m4_v3(mat, co);
				if ((ED_view3d_project_int_global(ar, co, screen_co, V3D_PROJ_TEST_CLIP_WIN) == V3D_PROJ_RET_OK) &&
				    BLI_lasso_is_point_inside(mcords, moves, screen_co[0], screen_co[1], IS_CLIPPED) &&
				    key_test_depth(&data, co, screen_co))
				{
					if (select) {
						if (!(key->flag & PEK_SELECT)) {
							key->flag |= PEK_SELECT;
							point->flag |= PEP_EDIT_RECALC;
						}
					}
					else {
						if (key->flag & PEK_SELECT) {
							key->flag &= ~PEK_SELECT;
							point->flag |= PEP_EDIT_RECALC;
						}
					}
				}
			}
		}
	}

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

/*************************** hide operator **************************/

static int hide_exec(bContext *C, wmOperator *op)
{
	Object *ob= CTX_data_active_object(C);
	Scene *scene= CTX_data_scene(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	POINT_P; KEY_K;
	
	if (RNA_enum_get(op->ptr, "unselected")) {
		LOOP_UNSELECTED_POINTS {
			point->flag |= PEP_HIDE;
			point->flag |= PEP_EDIT_RECALC;

			LOOP_KEYS
				key->flag &= ~PEK_SELECT;
		}
	}
	else {
		LOOP_SELECTED_POINTS {
			point->flag |= PEP_HIDE;
			point->flag |= PEP_EDIT_RECALC;

			LOOP_KEYS
				key->flag &= ~PEK_SELECT;
		}
	}

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_hide(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Hide Selected";
	ot->idname = "PARTICLE_OT_hide";
	ot->description = "Hide selected particles";
	
	/* api callbacks */
	ot->exec = hide_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* props */
	RNA_def_boolean(ot->srna, "unselected", 0, "Unselected", "Hide unselected rather than selected");
}

/*************************** reveal operator **************************/

static int reveal_exec(bContext *C, wmOperator *UNUSED(op))
{
	Object *ob= CTX_data_active_object(C);
	Scene *scene= CTX_data_scene(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	POINT_P; KEY_K;

	LOOP_POINTS {
		if (point->flag & PEP_HIDE) {
			point->flag &= ~PEP_HIDE;
			point->flag |= PEP_EDIT_RECALC;

			LOOP_KEYS
				key->flag |= PEK_SELECT;
		}
	}

	PE_update_selection(scene, ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_reveal(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Reveal";
	ot->idname = "PARTICLE_OT_reveal";
	ot->description = "Show hidden particles";
	
	/* api callbacks */
	ot->exec = reveal_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************ select less operator ************************/

static void select_less_keys(PEData *data, int point_index)
{
	PTCacheEdit *edit= data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	KEY_K;

	LOOP_SELECTED_KEYS {
		if (k==0) {
			if (((key+1)->flag&PEK_SELECT)==0)
				key->flag |= PEK_TAG;
		}
		else if (k==point->totkey-1) {
			if (((key-1)->flag&PEK_SELECT)==0)
				key->flag |= PEK_TAG;
		}
		else {
			if ((((key-1)->flag & (key+1)->flag) & PEK_SELECT)==0)
				key->flag |= PEK_TAG;
		}
	}

	LOOP_KEYS {
		if (key->flag&PEK_TAG) {
			key->flag &= ~(PEK_TAG|PEK_SELECT);
			point->flag |= PEP_EDIT_RECALC; /* redraw selection only */
		}
	}
}

static int select_less_exec(bContext *C, wmOperator *UNUSED(op))
{
	PEData data;

	PE_set_data(C, &data);
	foreach_point(&data, select_less_keys);

	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_less(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Less";
	ot->idname = "PARTICLE_OT_select_less";
	ot->description = "Deselect boundary selected keys of each particle";
	
	/* api callbacks */
	ot->exec = select_less_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************ select more operator ************************/

static void select_more_keys(PEData *data, int point_index)
{
	PTCacheEdit *edit= data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	KEY_K;

	LOOP_KEYS {
		if (key->flag & PEK_SELECT) continue;

		if (k==0) {
			if ((key+1)->flag&PEK_SELECT)
				key->flag |= PEK_TAG;
		}
		else if (k==point->totkey-1) {
			if ((key-1)->flag&PEK_SELECT)
				key->flag |= PEK_TAG;
		}
		else {
			if (((key-1)->flag | (key+1)->flag) & PEK_SELECT)
				key->flag |= PEK_TAG;
		}
	}

	LOOP_KEYS {
		if (key->flag&PEK_TAG) {
			key->flag &= ~PEK_TAG;
			key->flag |= PEK_SELECT;
			point->flag |= PEP_EDIT_RECALC; /* redraw selection only */
		}
	}
}

static int select_more_exec(bContext *C, wmOperator *UNUSED(op))
{
	PEData data;

	PE_set_data(C, &data);
	foreach_point(&data, select_more_keys);

	PE_update_selection(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_SELECTED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_select_more(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select More";
	ot->idname = "PARTICLE_OT_select_more";
	ot->description = "Select keys linked to boundary selected keys of each particle";
	
	/* api callbacks */
	ot->exec = select_more_exec;
	ot->poll = PE_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************ rekey operator ************************/

static void rekey_particle(PEData *data, int pa_index)
{
	PTCacheEdit *edit= data->edit;
	ParticleSystem *psys= edit->psys;
	ParticleSimulationData sim= {0};
	ParticleData *pa= psys->particles + pa_index;
	PTCacheEditPoint *point = edit->points + pa_index;
	ParticleKey state;
	HairKey *key, *new_keys, *okey;
	PTCacheEditKey *ekey;
	float dval, sta, end;
	int k;

	sim.scene= data->scene;
	sim.ob= data->ob;
	sim.psys= edit->psys;

	pa->flag |= PARS_REKEY;

	key= new_keys= MEM_callocN(data->totrekey * sizeof(HairKey), "Hair re-key keys");

	okey = pa->hair;
	/* root and tip stay the same */
	copy_v3_v3(key->co, okey->co);
	copy_v3_v3((key + data->totrekey - 1)->co, (okey + pa->totkey - 1)->co);

	sta= key->time= okey->time;
	end= (key + data->totrekey - 1)->time= (okey + pa->totkey - 1)->time;
	dval= (end - sta) / (float)(data->totrekey - 1);

	/* interpolate new keys from old ones */
	for (k=1, key++; k<data->totrekey-1; k++, key++) {
		state.time= (float)k / (float)(data->totrekey-1);
		psys_get_particle_on_path(&sim, pa_index, &state, 0);
		copy_v3_v3(key->co, state.co);
		key->time= sta + k * dval;
	}

	/* replace keys */
	if (pa->hair)
		MEM_freeN(pa->hair);
	pa->hair= new_keys;

	point->totkey=pa->totkey=data->totrekey;


	if (point->keys)
		MEM_freeN(point->keys);
	ekey= point->keys= MEM_callocN(pa->totkey * sizeof(PTCacheEditKey), "Hair re-key edit keys");
		
	for (k=0, key=pa->hair; k<pa->totkey; k++, key++, ekey++) {
		ekey->co= key->co;
		ekey->time= &key->time;
		ekey->flag |= PEK_SELECT;
		if (!(psys->flag & PSYS_GLOBAL_HAIR))
			ekey->flag |= PEK_USE_WCO;
	}

	pa->flag &= ~PARS_REKEY;
	point->flag |= PEP_EDIT_RECALC;
}

static int rekey_exec(bContext *C, wmOperator *op)
{
	PEData data;

	PE_set_data(C, &data);

	data.dval= 1.0f / (float)(data.totrekey-1);
	data.totrekey= RNA_int_get(op->ptr, "keys_number");

	foreach_selected_point(&data, rekey_particle);
	
	recalc_lengths(data.edit);
	PE_update_object(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_rekey(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Rekey";
	ot->idname = "PARTICLE_OT_rekey";
	ot->description = "Change the number of keys of selected particles (root and tip keys included)";
	
	/* api callbacks */
	ot->exec = rekey_exec;
	ot->invoke = WM_operator_props_popup;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	RNA_def_int(ot->srna, "keys_number", 2, 2, INT_MAX, "Number of Keys", "", 2, 100);
}

static void rekey_particle_to_time(Scene *scene, Object *ob, int pa_index, float path_time)
{
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ParticleSystem *psys;
	ParticleSimulationData sim= {0};
	ParticleData *pa;
	ParticleKey state;
	HairKey *new_keys, *key;
	PTCacheEditKey *ekey;
	int k;

	if (!edit || !edit->psys) return;

	psys = edit->psys;

	sim.scene= scene;
	sim.ob= ob;
	sim.psys= psys;

	pa= psys->particles + pa_index;

	pa->flag |= PARS_REKEY;

	key= new_keys= MEM_dupallocN(pa->hair);
	
	/* interpolate new keys from old ones (roots stay the same) */
	for (k=1, key++; k < pa->totkey; k++, key++) {
		state.time= path_time * (float)k / (float)(pa->totkey-1);
		psys_get_particle_on_path(&sim, pa_index, &state, 0);
		copy_v3_v3(key->co, state.co);
	}

	/* replace hair keys */
	if (pa->hair)
		MEM_freeN(pa->hair);
	pa->hair= new_keys;

	/* update edit pointers */
	for (k=0, key=pa->hair, ekey=edit->points[pa_index].keys; k<pa->totkey; k++, key++, ekey++) {
		ekey->co= key->co;
		ekey->time= &key->time;
	}

	pa->flag &= ~PARS_REKEY;
}

/************************* utilities **************************/

static int remove_tagged_particles(Object *ob, ParticleSystem *psys, int mirror)
{
	PTCacheEdit *edit = psys->edit;
	ParticleData *pa, *npa=0, *new_pars=0;
	POINT_P;
	PTCacheEditPoint *npoint=0, *new_points=0;
	ParticleSystemModifierData *psmd;
	int i, new_totpart= psys->totpart, removed= 0;

	if (mirror) {
		/* mirror tags */
		psmd= psys_get_modifier(ob, psys);

		LOOP_TAGGED_POINTS {
			PE_mirror_particle(ob, psmd->dm_final, psys, psys->particles + p, NULL);
		}
	}

	LOOP_TAGGED_POINTS {
		new_totpart--;
		removed++;
	}

	if (new_totpart != psys->totpart) {
		if (new_totpart) {
			npa= new_pars= MEM_callocN(new_totpart * sizeof(ParticleData), "ParticleData array");
			npoint= new_points= MEM_callocN(new_totpart * sizeof(PTCacheEditPoint), "PTCacheEditKey array");

			if (ELEM(NULL, new_pars, new_points)) {
				/* allocation error! */
				if (new_pars)
					MEM_freeN(new_pars);
				if (new_points)
					MEM_freeN(new_points);
				return 0;
			}
		}

		pa= psys->particles;
		point= edit->points;
		for (i=0; i<psys->totpart; i++, pa++, point++) {
			if (point->flag & PEP_TAG) {
				if (point->keys)
					MEM_freeN(point->keys);
				if (pa->hair)
					MEM_freeN(pa->hair);
			}
			else {
				memcpy(npa, pa, sizeof(ParticleData));
				memcpy(npoint, point, sizeof(PTCacheEditPoint));
				npa++;
				npoint++;
			}
		}

		if (psys->particles) MEM_freeN(psys->particles);
		psys->particles= new_pars;

		if (edit->points) MEM_freeN(edit->points);
		edit->points= new_points;

		if (edit->mirror_cache) {
			MEM_freeN(edit->mirror_cache);
			edit->mirror_cache= NULL;
		}

		if (psys->child) {
			MEM_freeN(psys->child);
			psys->child= NULL;
			psys->totchild=0;
		}

		edit->totpoint= psys->totpart= new_totpart;
	}

	return removed;
}

static void remove_tagged_keys(Object *ob, ParticleSystem *psys)
{
	PTCacheEdit *edit= psys->edit;
	ParticleData *pa;
	HairKey *hkey, *nhkey, *new_hkeys=0;
	POINT_P; KEY_K;
	PTCacheEditKey *nkey, *new_keys;
	ParticleSystemModifierData *psmd;
	short new_totkey;

	if (pe_x_mirror(ob)) {
		/* mirror key tags */
		psmd= psys_get_modifier(ob, psys);

		LOOP_POINTS {
			LOOP_TAGGED_KEYS {
				PE_mirror_particle(ob, psmd->dm_final, psys, psys->particles + p, NULL);
				break;
			}
		}
	}

	LOOP_POINTS {
		new_totkey= point->totkey;
		LOOP_TAGGED_KEYS {
			new_totkey--;
		}
		/* we can't have elements with less than two keys*/
		if (new_totkey < 2)
			point->flag |= PEP_TAG;
	}
	remove_tagged_particles(ob, psys, pe_x_mirror(ob));

	LOOP_POINTS {
		pa = psys->particles + p;
		new_totkey= pa->totkey;

		LOOP_TAGGED_KEYS {
			new_totkey--;
		}

		if (new_totkey != pa->totkey) {
			nhkey= new_hkeys= MEM_callocN(new_totkey*sizeof(HairKey), "HairKeys");
			nkey= new_keys= MEM_callocN(new_totkey*sizeof(PTCacheEditKey), "particle edit keys");

			hkey= pa->hair;
			LOOP_KEYS {
				while (key->flag & PEK_TAG && hkey < pa->hair + pa->totkey) {
					key++;
					hkey++;
				}

				if (hkey < pa->hair + pa->totkey) {
					copy_v3_v3(nhkey->co, hkey->co);
					nhkey->editflag = hkey->editflag;
					nhkey->time= hkey->time;
					nhkey->weight= hkey->weight;
					
					nkey->co= nhkey->co;
					nkey->time= &nhkey->time;
					/* these can be copied from old edit keys */
					nkey->flag = key->flag;
					nkey->ftime = key->ftime;
					nkey->length = key->length;
					copy_v3_v3(nkey->world_co, key->world_co);
				}
				nkey++;
				nhkey++;
				hkey++;
			}

			if (pa->hair)
				MEM_freeN(pa->hair);

			if (point->keys)
				MEM_freeN(point->keys);
			
			pa->hair= new_hkeys;
			point->keys= new_keys;

			point->totkey= pa->totkey= new_totkey;

			/* flag for recalculating length */
			point->flag |= PEP_EDIT_RECALC;
		}
	}
}

/************************ subdivide opertor *********************/

/* works like normal edit mode subdivide, inserts keys between neighboring selected keys */
static void subdivide_particle(PEData *data, int pa_index)
{
	PTCacheEdit *edit= data->edit;
	ParticleSystem *psys= edit->psys;
	ParticleSimulationData sim= {0};
	ParticleData *pa= psys->particles + pa_index;
	PTCacheEditPoint *point = edit->points + pa_index;
	ParticleKey state;
	HairKey *key, *nkey, *new_keys;
	PTCacheEditKey *ekey, *nekey, *new_ekeys;

	int k;
	short totnewkey=0;
	float endtime;

	sim.scene= data->scene;
	sim.ob= data->ob;
	sim.psys= edit->psys;

	for (k=0, ekey=point->keys; k<pa->totkey-1; k++, ekey++) {
		if (ekey->flag&PEK_SELECT && (ekey+1)->flag&PEK_SELECT)
			totnewkey++;
	}

	if (totnewkey==0) return;

	pa->flag |= PARS_REKEY;

	nkey= new_keys= MEM_callocN((pa->totkey+totnewkey)*(sizeof(HairKey)), "Hair subdivide keys");
	nekey= new_ekeys= MEM_callocN((pa->totkey+totnewkey)*(sizeof(PTCacheEditKey)), "Hair subdivide edit keys");
	
	key = pa->hair;
	endtime= key[pa->totkey-1].time;

	for (k=0, ekey=point->keys; k<pa->totkey-1; k++, key++, ekey++) {

		memcpy(nkey, key, sizeof(HairKey));
		memcpy(nekey, ekey, sizeof(PTCacheEditKey));

		nekey->co= nkey->co;
		nekey->time= &nkey->time;

		nkey++;
		nekey++;

		if (ekey->flag & PEK_SELECT && (ekey+1)->flag & PEK_SELECT) {
			nkey->time = (key->time + (key + 1)->time) * 0.5f;
			state.time = (endtime != 0.0f) ? nkey->time / endtime: 0.0f;
			psys_get_particle_on_path(&sim, pa_index, &state, 0);
			copy_v3_v3(nkey->co, state.co);

			nekey->co= nkey->co;
			nekey->time = &nkey->time;
			nekey->flag |= PEK_SELECT;
			if (!(psys->flag & PSYS_GLOBAL_HAIR))
				nekey->flag |= PEK_USE_WCO;

			nekey++;
			nkey++;
		}
	}
	/*tip still not copied*/
	memcpy(nkey, key, sizeof(HairKey));
	memcpy(nekey, ekey, sizeof(PTCacheEditKey));

	nekey->co= nkey->co;
	nekey->time= &nkey->time;

	if (pa->hair)
		MEM_freeN(pa->hair);
	pa->hair= new_keys;

	if (point->keys)
		MEM_freeN(point->keys);
	point->keys= new_ekeys;

	point->totkey = pa->totkey = pa->totkey + totnewkey;
	point->flag |= PEP_EDIT_RECALC;
	pa->flag &= ~PARS_REKEY;
}

static int subdivide_exec(bContext *C, wmOperator *UNUSED(op))
{
	PEData data;

	PE_set_data(C, &data);
	foreach_point(&data, subdivide_particle);
	
	recalc_lengths(data.edit);
	PE_update_object(data.scene, data.ob, 1);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_subdivide(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Subdivide";
	ot->idname = "PARTICLE_OT_subdivide";
	ot->description = "Subdivide selected particles segments (adds keys)";
	
	/* api callbacks */
	ot->exec = subdivide_exec;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************ remove doubles opertor *********************/

static int remove_doubles_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ParticleSystem *psys = edit->psys;
	ParticleSystemModifierData *psmd;
	KDTree *tree;
	KDTreeNearest nearest[10];
	POINT_P;
	float mat[4][4], co[3], threshold= RNA_float_get(op->ptr, "threshold");
	int n, totn, removed, totremoved;

	if (psys->flag & PSYS_GLOBAL_HAIR)
		return OPERATOR_CANCELLED;

	edit= psys->edit;
	psmd= psys_get_modifier(ob, psys);
	totremoved= 0;

	do {
		removed= 0;

		tree=BLI_kdtree_new(psys->totpart);
			
		/* insert particles into kd tree */
		LOOP_SELECTED_POINTS {
			psys_mat_hair_to_object(ob, psmd->dm_final, psys->part->from, psys->particles+p, mat);
			copy_v3_v3(co, point->keys->co);
			mul_m4_v3(mat, co);
			BLI_kdtree_insert(tree, p, co);
		}

		BLI_kdtree_balance(tree);

		/* tag particles to be removed */
		LOOP_SELECTED_POINTS {
			psys_mat_hair_to_object(ob, psmd->dm_final, psys->part->from, psys->particles+p, mat);
			copy_v3_v3(co, point->keys->co);
			mul_m4_v3(mat, co);

			totn = BLI_kdtree_find_nearest_n(tree, co, nearest, 10);

			for (n=0; n<totn; n++) {
				/* this needs a custom threshold still */
				if (nearest[n].index > p && nearest[n].dist < threshold) {
					if (!(point->flag & PEP_TAG)) {
						point->flag |= PEP_TAG;
						removed++;
					}
				}
			}
		}

		BLI_kdtree_free(tree);

		/* remove tagged particles - don't do mirror here! */
		remove_tagged_particles(ob, psys, 0);
		totremoved += removed;
	} while (removed);

	if (totremoved == 0)
		return OPERATOR_CANCELLED;

	BKE_reportf(op->reports, RPT_INFO, "Removed %d double particles", totremoved);

	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_remove_doubles(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove Doubles";
	ot->idname = "PARTICLE_OT_remove_doubles";
	ot->description = "Remove selected particles close enough of others";
	
	/* api callbacks */
	ot->exec = remove_doubles_exec;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	RNA_def_float(ot->srna, "threshold", 0.0002f, 0.0f, FLT_MAX,
	              "Merge Distance", "Threshold distance withing which particles are removed", 0.00001f, 0.1f);
}


static int weight_set_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	ParticleEditSettings *pset= PE_settings(scene);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ParticleSystem *psys = edit->psys;
	POINT_P;
	KEY_K;
	HairKey *hkey;
	float weight;
	ParticleBrushData *brush= &pset->brush[pset->brushtype];
	float factor= RNA_float_get(op->ptr, "factor");

	weight= brush->strength;
	edit= psys->edit;

	LOOP_SELECTED_POINTS {
		ParticleData *pa= psys->particles + p;

		LOOP_SELECTED_KEYS {
			hkey= pa->hair + k;
			hkey->weight= interpf(weight, hkey->weight, factor);
		}
	}

	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_weight_set(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Weight Set";
	ot->idname = "PARTICLE_OT_weight_set";
	ot->description = "Set the weight of selected keys";

	/* api callbacks */
	ot->exec = weight_set_exec;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	RNA_def_float(ot->srna, "factor", 1, 0, 1, "Factor",
	              "Interpolation factor between current brush weight, and keys' weights", 0, 1);
}

/************************ cursor drawing *******************************/

static void brush_drawcursor(bContext *C, int x, int y, void *UNUSED(customdata))
{
	Scene *scene = CTX_data_scene(C);
	ParticleEditSettings *pset= PE_settings(scene);
	ParticleBrushData *brush;

	if (pset->brushtype < 0)
		return;

	brush= &pset->brush[pset->brushtype];

	if (brush) {
		glPushMatrix();

		glTranslatef((float)x, (float)y, 0.0f);

		glColor4ub(255, 255, 255, 128);
		glEnable(GL_LINE_SMOOTH);
		glEnable(GL_BLEND);
		glutil_draw_lined_arc(0.0, M_PI*2.0, pe_brush_size_get(scene, brush), 40);
		glDisable(GL_BLEND);
		glDisable(GL_LINE_SMOOTH);
		
		glPopMatrix();
	}
}

static void toggle_particle_cursor(bContext *C, int enable)
{
	ParticleEditSettings *pset= PE_settings(CTX_data_scene(C));

	if (pset->paintcursor && !enable) {
		WM_paint_cursor_end(CTX_wm_manager(C), pset->paintcursor);
		pset->paintcursor = NULL;
	}
	else if (enable)
		pset->paintcursor= WM_paint_cursor_activate(CTX_wm_manager(C), PE_poll_view3d, brush_drawcursor, NULL);
}

/*************************** delete operator **************************/

enum { DEL_PARTICLE, DEL_KEY };

static EnumPropertyItem delete_type_items[] = {
	{DEL_PARTICLE, "PARTICLE", 0, "Particle", ""},
	{DEL_KEY, "KEY", 0, "Key", ""},
	{0, NULL, 0, NULL, NULL}};

static void set_delete_particle(PEData *data, int pa_index)
{
	PTCacheEdit *edit= data->edit;

	edit->points[pa_index].flag |= PEP_TAG;
}

static void set_delete_particle_key(PEData *data, int pa_index, int key_index)
{
	PTCacheEdit *edit= data->edit;

	edit->points[pa_index].keys[key_index].flag |= PEK_TAG;
}

static int delete_exec(bContext *C, wmOperator *op)
{
	PEData data;
	int type= RNA_enum_get(op->ptr, "type");

	PE_set_data(C, &data);

	if (type == DEL_KEY) {
		foreach_selected_key(&data, set_delete_particle_key);
		remove_tagged_keys(data.ob, data.edit->psys);
		recalc_lengths(data.edit);
	}
	else if (type == DEL_PARTICLE) {
		foreach_selected_point(&data, set_delete_particle);
		remove_tagged_particles(data.ob, data.edit->psys, pe_x_mirror(data.ob));
		recalc_lengths(data.edit);
	}

	DAG_id_tag_update(&data.ob->id, OB_RECALC_DATA);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, data.ob);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_delete(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Delete";
	ot->idname = "PARTICLE_OT_delete";
	ot->description = "Delete selected particles or keys";
	
	/* api callbacks */
	ot->exec = delete_exec;
	ot->invoke = WM_menu_invoke;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	ot->prop = RNA_def_enum(ot->srna, "type", delete_type_items, DEL_PARTICLE, "Type", "Delete a full particle or only keys");
}

/*************************** mirror operator **************************/

static void PE_mirror_x(Scene *scene, Object *ob, int tagged)
{
	Mesh *me= (Mesh *)(ob->data);
	ParticleSystemModifierData *psmd;
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ParticleSystem *psys = edit->psys;
	ParticleData *pa, *newpa, *new_pars;
	PTCacheEditPoint *newpoint, *new_points;
	POINT_P; KEY_K;
	HairKey *hkey;
	int *mirrorfaces = NULL;
	int rotation, totpart, newtotpart;

	if (psys->flag & PSYS_GLOBAL_HAIR)
		return;

	psmd= psys_get_modifier(ob, psys);
	if (!psmd->dm_final)
		return;

	const bool use_dm_final_indices = (psys->part->use_modifier_stack && !psmd->dm_final->deformedOnly);

	/* NOTE: this is not nice to use tessfaces but hard to avoid since pa->num uses tessfaces */
	BKE_mesh_tessface_ensure(me);

	/* Note: In case psys uses DM tessface indices, we mirror final DM itself, not orig mesh. Avoids an (impossible)
	 *       dm -> orig -> dm tessface indices conversion... */
	mirrorfaces = mesh_get_x_mirror_faces(ob, NULL, use_dm_final_indices ? psmd->dm_final : NULL);

	if (!edit->mirror_cache)
		PE_update_mirror_cache(ob, psys);

	totpart= psys->totpart;
	newtotpart= psys->totpart;
	LOOP_VISIBLE_POINTS {
		pa = psys->particles + p;

		if (!tagged) {
			if (point_is_selected(point)) {
				if (edit->mirror_cache[p] != -1) {
					/* already has a mirror, don't need to duplicate */
					PE_mirror_particle(ob, psmd->dm_final, psys, pa, NULL);
					continue;
				}
				else
					point->flag |= PEP_TAG;
			}
		}

		if ((point->flag & PEP_TAG) && mirrorfaces[pa->num*2] != -1)
			newtotpart++;
	}

	if (newtotpart != psys->totpart) {
		MFace *mtessface = use_dm_final_indices ? psmd->dm_final->getTessFaceArray(psmd->dm_final) : me->mface;

		/* allocate new arrays and copy existing */
		new_pars= MEM_callocN(newtotpart*sizeof(ParticleData), "ParticleData new");
		new_points= MEM_callocN(newtotpart*sizeof(PTCacheEditPoint), "PTCacheEditPoint new");

		if (psys->particles) {
			memcpy(new_pars, psys->particles, totpart*sizeof(ParticleData));
			MEM_freeN(psys->particles);
		}
		psys->particles= new_pars;

		if (edit->points) {
			memcpy(new_points, edit->points, totpart*sizeof(PTCacheEditPoint));
			MEM_freeN(edit->points);
		}
		edit->points= new_points;

		if (edit->mirror_cache) {
			MEM_freeN(edit->mirror_cache);
			edit->mirror_cache= NULL;
		}

		edit->totpoint= psys->totpart= newtotpart;
			
		/* create new elements */
		newpa= psys->particles + totpart;
		newpoint= edit->points + totpart;

		for (p=0, point=edit->points; p<totpart; p++, point++) {
			pa = psys->particles + p;
			const int pa_num = pa->num;

			if (point->flag & PEP_HIDE)
				continue;

			if (!(point->flag & PEP_TAG) || mirrorfaces[pa_num * 2] == -1)
				continue;

			/* duplicate */
			*newpa= *pa;
			*newpoint= *point;
			if (pa->hair) newpa->hair= MEM_dupallocN(pa->hair);
			if (point->keys) newpoint->keys= MEM_dupallocN(point->keys);

			/* rotate weights according to vertex index rotation */
			rotation= mirrorfaces[pa_num * 2 + 1];
			newpa->fuv[0] = pa->fuv[2];
			newpa->fuv[1] = pa->fuv[1];
			newpa->fuv[2] = pa->fuv[0];
			newpa->fuv[3] = pa->fuv[3];
			while (rotation--) {
				if (mtessface[pa_num].v4) {
					SHIFT4(float, newpa->fuv[0], newpa->fuv[1], newpa->fuv[2], newpa->fuv[3]);
				}
				else {
					SHIFT3(float, newpa->fuv[0], newpa->fuv[1], newpa->fuv[2]);
				}
			}

			/* assign face index */
			/* NOTE: mesh_get_x_mirror_faces generates -1 for non-found mirror, same as DMCACHE_NOTFOUND... */
			newpa->num = mirrorfaces[pa_num * 2];

			if (use_dm_final_indices) {
				newpa->num_dmcache = DMCACHE_ISCHILD;
			}
			else {
				newpa->num_dmcache = psys_particle_dm_face_lookup(
				                         psmd->dm_final, psmd->dm_deformed, newpa->num, newpa->fuv, NULL);
			}

			/* update edit key pointers */
			key= newpoint->keys;
			for (k=0, hkey=newpa->hair; k<newpa->totkey; k++, hkey++, key++) {
				key->co= hkey->co;
				key->time= &hkey->time;
			}

			/* map key positions as mirror over x axis */
			PE_mirror_particle(ob, psmd->dm_final, psys, pa, newpa);

			newpa++;
			newpoint++;
		}
	}

	LOOP_POINTS {
		point->flag &= ~PEP_TAG;
	}

	MEM_freeN(mirrorfaces);
}

static int mirror_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	
	PE_mirror_x(scene, ob, 0);

	update_world_cos(ob, edit);
	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_mirror(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Mirror";
	ot->idname = "PARTICLE_OT_mirror";
	ot->description = "Duplicate and mirror the selected particles along the local X axis";
	
	/* api callbacks */
	ot->exec = mirror_exec;
	ot->poll = PE_hair_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************* brush edit callbacks ********************/

static void brush_comb(PEData *data, float UNUSED(mat[4][4]), float imat[4][4], int point_index, int key_index, PTCacheEditKey *key)
{
	ParticleEditSettings *pset= PE_settings(data->scene);
	float cvec[3], fac;

	if (pset->flag & PE_LOCK_FIRST && key_index == 0) return;

	fac= (float)pow((double)(1.0f - data->dist / data->rad), (double)data->combfac);

	copy_v3_v3(cvec, data->dvec);
	mul_mat3_m4_v3(imat, cvec);
	mul_v3_fl(cvec, fac);
	add_v3_v3(key->co, cvec);

	(data->edit->points + point_index)->flag |= PEP_EDIT_RECALC;
}

static void brush_cut(PEData *data, int pa_index)
{
	PTCacheEdit *edit = data->edit;
	ARegion *ar= data->vc.ar;
	Object *ob= data->ob;
	ParticleEditSettings *pset= PE_settings(data->scene);
	ParticleCacheKey *key= edit->pathcache[pa_index];
	float rad2, cut_time= 1.0;
	float x0, x1, v0, v1, o0, o1, xo0, xo1, d, dv;
	int k, cut, keys= (int)pow(2.0, (double)pset->draw_step);
	int screen_co[2];

	/* blunt scissors */
	if (BLI_frand() > data->cutfac) return;

	/* don't cut hidden */
	if (edit->points[pa_index].flag & PEP_HIDE)
		return;

	if (ED_view3d_project_int_global(ar, key->co, screen_co, V3D_PROJ_TEST_CLIP_NEAR) != V3D_PROJ_RET_OK)
		return;

	rad2= data->rad * data->rad;

	cut=0;

	x0 = (float)screen_co[0];
	x1 = (float)screen_co[1];

	o0= (float)data->mval[0];
	o1= (float)data->mval[1];
	
	xo0= x0 - o0;
	xo1= x1 - o1;

	/* check if root is inside circle */
	if (xo0*xo0 + xo1*xo1 < rad2 && key_test_depth(data, key->co, screen_co)) {
		cut_time= -1.0f;
		cut= 1;
	}
	else {
		/* calculate path time closest to root that was inside the circle */
		for (k=1, key++; k<=keys; k++, key++) {

			if ((ED_view3d_project_int_global(ar, key->co, screen_co, V3D_PROJ_TEST_CLIP_NEAR) != V3D_PROJ_RET_OK) ||
			    key_test_depth(data, key->co, screen_co) == 0)
			{
				x0 = (float)screen_co[0];
				x1 = (float)screen_co[1];

				xo0= x0 - o0;
				xo1= x1 - o1;
				continue;
			}

			v0 = (float)screen_co[0] - x0;
			v1 = (float)screen_co[1] - x1;

			dv= v0*v0 + v1*v1;

			d= (v0*xo1 - v1*xo0);
			
			d= dv * rad2 - d*d;

			if (d > 0.0f) {
				d= sqrtf(d);

				cut_time= -(v0*xo0 + v1*xo1 + d);

				if (cut_time > 0.0f) {
					cut_time /= dv;

					if (cut_time < 1.0f) {
						cut_time += (float)(k-1);
						cut_time /= (float)keys;
						cut= 1;
						break;
					}
				}
			}

			x0 = (float)screen_co[0];
			x1 = (float)screen_co[1];

			xo0= x0 - o0;
			xo1= x1 - o1;
		}
	}

	if (cut) {
		if (cut_time < 0.0f) {
			edit->points[pa_index].flag |= PEP_TAG;
		}
		else {
			rekey_particle_to_time(data->scene, ob, pa_index, cut_time);
			edit->points[pa_index].flag |= PEP_EDIT_RECALC;
		}
	}
}

static void brush_length(PEData *data, int point_index)
{
	PTCacheEdit *edit= data->edit;
	PTCacheEditPoint *point = edit->points + point_index;
	KEY_K;
	float dvec[3], pvec[3] = {0.0f, 0.0f, 0.0f};

	LOOP_KEYS {
		if (k==0) {
			copy_v3_v3(pvec, key->co);
		}
		else {
			sub_v3_v3v3(dvec, key->co, pvec);
			copy_v3_v3(pvec, key->co);
			mul_v3_fl(dvec, data->growfac);
			add_v3_v3v3(key->co, (key-1)->co, dvec);
		}
	}

	point->flag |= PEP_EDIT_RECALC;
}

static void brush_puff(PEData *data, int point_index)
{
	PTCacheEdit *edit = data->edit;
	ParticleSystem *psys = edit->psys;
	PTCacheEditPoint *point = edit->points + point_index;
	KEY_K;
	float mat[4][4], imat[4][4];

	float onor_prev[3];  /* previous normal (particle-space) */
	float ofs_prev[3];  /* accumulate offset for puff_volume (particle-space) */
	float co_root[3], no_root[3];  /* root location and normal (global-space) */
	float co_prev[3], co[3];  /* track key coords as we loop (global-space) */
	float fac = 0.0f, length_accum = 0.0f;
	bool puff_volume = false;
	bool changed = false;

	zero_v3(ofs_prev);

	{
		ParticleEditSettings *pset= PE_settings(data->scene);
		ParticleBrushData *brush= &pset->brush[pset->brushtype];
		puff_volume = (brush->flag & PE_BRUSH_DATA_PUFF_VOLUME) != 0;
	}

	if (psys && !(psys->flag & PSYS_GLOBAL_HAIR)) {
		psys_mat_hair_to_global(data->ob, data->dm, psys->part->from, psys->particles + point_index, mat);
		invert_m4_m4(imat, mat);
	}
	else {
		unit_m4(mat);
		unit_m4(imat);
	}

	LOOP_KEYS {
		float kco[3];

		if (k==0) {
			/* find root coordinate and normal on emitter */
			copy_v3_v3(co, key->co);
			mul_m4_v3(mat, co);
			mul_v3_m4v3(kco, data->ob->imat, co); /* use 'kco' as the object space version of worldspace 'co', ob->imat is set before calling */

			point_index= BLI_kdtree_find_nearest(edit->emitter_field, kco, NULL);
			if (point_index == -1) return;

			copy_v3_v3(co_root, co);
			copy_v3_v3(no_root, &edit->emitter_cosnos[point_index * 6 + 3]);
			mul_mat3_m4_v3(data->ob->obmat, no_root);  /* normal into global-space */
			normalize_v3(no_root);

			if (puff_volume) {
				copy_v3_v3(onor_prev, no_root);
				mul_mat3_m4_v3(imat, onor_prev); /* global-space into particle space */
				normalize_v3(onor_prev);
			}

			fac= (float)pow((double)(1.0f - data->dist / data->rad), (double)data->pufffac);
			fac *= 0.025f;
			if (data->invert)
				fac= -fac;
		}
		else {
			/* compute position as if hair was standing up straight.
			 * */
			float length;
			copy_v3_v3(co_prev, co);
			copy_v3_v3(co, key->co);
			mul_m4_v3(mat, co);
			length = len_v3v3(co_prev, co);
			length_accum += length;

			if ((data->select==0 || (key->flag & PEK_SELECT)) && !(key->flag & PEK_HIDE)) {
				float dco[3];  /* delta temp var */

				madd_v3_v3v3fl(kco, co_root, no_root, length_accum);

				/* blend between the current and straight position */
				sub_v3_v3v3(dco, kco, co);
				madd_v3_v3fl(co, dco, fac);
				/* keep the same distance from the root or we get glitches [#35406] */
				dist_ensure_v3_v3fl(co, co_root, length_accum);

				/* re-use dco to compare before and after translation and add to the offset  */
				copy_v3_v3(dco, key->co);

				mul_v3_m4v3(key->co, imat, co);

				if (puff_volume) {
					/* accumulate the total distance moved to apply to unselected
					 * keys that come after */
					sub_v3_v3v3(ofs_prev, key->co, dco);
				}
				changed = true;
			}
			else {

				if (puff_volume) {
#if 0
					/* this is simple but looks bad, adds annoying kinks */
					add_v3_v3(key->co, ofs);
#else
					/* translate (not rotate) the rest of the hair if its not selected  */
					{
#if 0					/* kindof works but looks worse then whats below */

						/* Move the unselected point on a vector based on the
						 * hair direction and the offset */
						float c1[3], c2[3];
						sub_v3_v3v3(dco, lastco, co);
						mul_mat3_m4_v3(imat, dco); /* into particle space */

						/* move the point along a vector perpendicular to the
						 * hairs direction, reduces odd kinks, */
						cross_v3_v3v3(c1, ofs, dco);
						cross_v3_v3v3(c2, c1, dco);
						normalize_v3(c2);
						mul_v3_fl(c2, len_v3(ofs));
						add_v3_v3(key->co, c2);
#else
						/* Move the unselected point on a vector based on the
						 * the normal of the closest geometry */
						float oco[3], onor[3];
						copy_v3_v3(oco, key->co);
						mul_m4_v3(mat, oco);
						mul_v3_m4v3(kco, data->ob->imat, oco); /* use 'kco' as the object space version of worldspace 'co', ob->imat is set before calling */

						point_index= BLI_kdtree_find_nearest(edit->emitter_field, kco, NULL);
						if (point_index != -1) {
							copy_v3_v3(onor, &edit->emitter_cosnos[point_index*6+3]);
							mul_mat3_m4_v3(data->ob->obmat, onor); /* normal into worldspace */
							mul_mat3_m4_v3(imat, onor); /* worldspace into particle space */
							normalize_v3(onor);
						}
						else {
							copy_v3_v3(onor, onor_prev);
						}

						if (!is_zero_v3(ofs_prev)) {
							mul_v3_fl(onor, len_v3(ofs_prev));

							add_v3_v3(key->co, onor);
						}

						copy_v3_v3(onor_prev, onor);
#endif
					}
#endif
				}
			}
		}
	}

	if (changed)
		point->flag |= PEP_EDIT_RECALC;
}


static void BKE_brush_weight_get(PEData *data, float UNUSED(mat[4][4]), float UNUSED(imat[4][4]), int point_index, int key_index, PTCacheEditKey *UNUSED(key))
{
	/* roots have full weight always */
	if (key_index) {
		PTCacheEdit *edit = data->edit;
		ParticleSystem *psys = edit->psys;

		ParticleData *pa= psys->particles + point_index;
		pa->hair[key_index].weight = data->weightfac;

		(data->edit->points + point_index)->flag |= PEP_EDIT_RECALC;
	}
}

static void brush_smooth_get(PEData *data, float mat[4][4], float UNUSED(imat[4][4]), int UNUSED(point_index), int key_index, PTCacheEditKey *key)
{	
	if (key_index) {
		float dvec[3];

		sub_v3_v3v3(dvec, key->co, (key-1)->co);
		mul_mat3_m4_v3(mat, dvec);
		add_v3_v3(data->vec, dvec);
		data->tot++;
	}
}

static void brush_smooth_do(PEData *data, float UNUSED(mat[4][4]), float imat[4][4], int point_index, int key_index, PTCacheEditKey *key)
{
	float vec[3], dvec[3];
	
	if (key_index) {
		copy_v3_v3(vec, data->vec);
		mul_mat3_m4_v3(imat, vec);

		sub_v3_v3v3(dvec, key->co, (key-1)->co);

		sub_v3_v3v3(dvec, vec, dvec);
		mul_v3_fl(dvec, data->smoothfac);
		
		add_v3_v3(key->co, dvec);
	}

	(data->edit->points + point_index)->flag |= PEP_EDIT_RECALC;
}

/* convert from triangle barycentric weights to quad mean value weights */
static void intersect_dm_quad_weights(const float v1[3], const float v2[3], const float v3[3], const float v4[3], float w[4])
{
	float co[3], vert[4][3];

	copy_v3_v3(vert[0], v1);
	copy_v3_v3(vert[1], v2);
	copy_v3_v3(vert[2], v3);
	copy_v3_v3(vert[3], v4);

	co[0] = v1[0]*w[0] + v2[0]*w[1] + v3[0]*w[2] + v4[0]*w[3];
	co[1] = v1[1]*w[0] + v2[1]*w[1] + v3[1]*w[2] + v4[1]*w[3];
	co[2] = v1[2]*w[0] + v2[2]*w[1] + v3[2]*w[2] + v4[2]*w[3];

	interp_weights_poly_v3(w, vert, 4, co);
}

/* check intersection with a derivedmesh */
static int particle_intersect_dm(Scene *scene, Object *ob, DerivedMesh *dm,
                                 float *vert_cos,
                                 const float co1[3], const float co2[3],
                                 float *min_d, int *min_face, float *min_w,
                                 float *face_minmax, float *pa_minmax,
                                 float radius, float *ipoint)
{
	MFace *mface= NULL;
	MVert *mvert= NULL;
	int i, totface, intersect=0;
	float cur_d, cur_uv[2], v1[3], v2[3], v3[3], v4[3], min[3], max[3], p_min[3], p_max[3];
	float cur_ipoint[3];
	
	if (dm == NULL) {
		psys_disable_all(ob);

		dm=mesh_get_derived_final(scene, ob, 0);
		if (dm == NULL)
			dm=mesh_get_derived_deform(scene, ob, 0);

		psys_enable_all(ob);

		if (dm == NULL)
			return 0;
	}

	/* BMESH_ONLY, deform dm may not have tessface */
	DM_ensure_tessface(dm);
	

	if (pa_minmax==0) {
		INIT_MINMAX(p_min, p_max);
		minmax_v3v3_v3(p_min, p_max, co1);
		minmax_v3v3_v3(p_min, p_max, co2);
	}
	else {
		copy_v3_v3(p_min, pa_minmax);
		copy_v3_v3(p_max, pa_minmax+3);
	}

	totface=dm->getNumTessFaces(dm);
	mface=dm->getTessFaceDataArray(dm, CD_MFACE);
	mvert=dm->getVertDataArray(dm, CD_MVERT);

	/* lets intersect the faces */
	for (i=0; i<totface; i++, mface++) {
		if (vert_cos) {
			copy_v3_v3(v1, vert_cos+3*mface->v1);
			copy_v3_v3(v2, vert_cos+3*mface->v2);
			copy_v3_v3(v3, vert_cos+3*mface->v3);
			if (mface->v4)
				copy_v3_v3(v4, vert_cos+3*mface->v4);
		}
		else {
			copy_v3_v3(v1, mvert[mface->v1].co);
			copy_v3_v3(v2, mvert[mface->v2].co);
			copy_v3_v3(v3, mvert[mface->v3].co);
			if (mface->v4)
				copy_v3_v3(v4, mvert[mface->v4].co);
		}

		if (face_minmax==0) {
			INIT_MINMAX(min, max);
			DO_MINMAX(v1, min, max);
			DO_MINMAX(v2, min, max);
			DO_MINMAX(v3, min, max);
			if (mface->v4)
				DO_MINMAX(v4, min, max);
			if (isect_aabb_aabb_v3(min, max, p_min, p_max)==0)
				continue;
		}
		else {
			copy_v3_v3(min, face_minmax+6*i);
			copy_v3_v3(max, face_minmax+6*i+3);
			if (isect_aabb_aabb_v3(min, max, p_min, p_max)==0)
				continue;
		}

		if (radius>0.0f) {
			if (isect_sweeping_sphere_tri_v3(co1, co2, radius, v2, v3, v1, &cur_d, cur_ipoint)) {
				if (cur_d<*min_d) {
					*min_d=cur_d;
					copy_v3_v3(ipoint, cur_ipoint);
					*min_face=i;
					intersect=1;
				}
			}
			if (mface->v4) {
				if (isect_sweeping_sphere_tri_v3(co1, co2, radius, v4, v1, v3, &cur_d, cur_ipoint)) {
					if (cur_d<*min_d) {
						*min_d=cur_d;
						copy_v3_v3(ipoint, cur_ipoint);
						*min_face=i;
						intersect=1;
					}
				}
			}
		}
		else {
			if (isect_line_segment_tri_v3(co1, co2, v1, v2, v3, &cur_d, cur_uv)) {
				if (cur_d<*min_d) {
					*min_d=cur_d;
					min_w[0] = 1.0f - cur_uv[0] - cur_uv[1];
					min_w[1] = cur_uv[0];
					min_w[2] = cur_uv[1];
					min_w[3] = 0.0f;
					if (mface->v4)
						intersect_dm_quad_weights(v1, v2, v3, v4, min_w);
					*min_face=i;
					intersect=1;
				}
			}
			if (mface->v4) {
				if (isect_line_segment_tri_v3(co1, co2, v1, v3, v4, &cur_d, cur_uv)) {
					if (cur_d<*min_d) {
						*min_d=cur_d;
						min_w[0] = 1.0f - cur_uv[0] - cur_uv[1];
						min_w[1] = 0.0f;
						min_w[2] = cur_uv[0];
						min_w[3] = cur_uv[1];
						intersect_dm_quad_weights(v1, v2, v3, v4, min_w);
						*min_face=i;
						intersect=1;
					}
				}
			}
		}
	}
	return intersect;
}

static int brush_add(PEData *data, short number)
{
	Scene *scene= data->scene;
	Object *ob= data->ob;
	DerivedMesh *dm;
	PTCacheEdit *edit = data->edit;
	ParticleSystem *psys= edit->psys;
	ParticleData *add_pars;
	ParticleSystemModifierData *psmd= psys_get_modifier(ob, psys);
	ParticleSimulationData sim= {0};
	ParticleEditSettings *pset= PE_settings(scene);
	int i, k, n= 0, totpart= psys->totpart;
	float mco[2];
	float dmx, dmy;
	float co1[3], co2[3], min_d, imat[4][4];
	float framestep, timestep;
	short size= pset->brush[PE_BRUSH_ADD].size;
	short size2= size*size;
	RNG *rng;

	invert_m4_m4(imat, ob->obmat);

	if (psys->flag & PSYS_GLOBAL_HAIR)
		return 0;

	add_pars = MEM_callocN(number * sizeof(ParticleData), "ParticleData add");

	rng = BLI_rng_new_srandom(psys->seed+data->mval[0]+data->mval[1]);

	sim.scene= scene;
	sim.ob= ob;
	sim.psys= psys;
	sim.psmd= psmd;

	timestep= psys_get_timestep(&sim);

	if (psys->part->use_modifier_stack || psmd->dm_final->deformedOnly) {
		dm = psmd->dm_final;
	}
	else {
		dm = psmd->dm_deformed;
	}
	BLI_assert(dm);

	for (i=0; i<number; i++) {
		if (number>1) {
			dmx = size;
			dmy = size;

			/* rejection sampling to get points in circle */
			while (dmx*dmx + dmy*dmy > size2) {
				dmx= (2.0f*BLI_rng_get_float(rng) - 1.0f)*size;
				dmy= (2.0f*BLI_rng_get_float(rng) - 1.0f)*size;
			}
		}
		else {
			dmx = 0.0f;
			dmy = 0.0f;
		}

		mco[0] = data->mval[0] + dmx;
		mco[1] = data->mval[1] + dmy;
		ED_view3d_win_to_segment(data->vc.ar, data->vc.v3d, mco, co1, co2, true);

		mul_m4_v3(imat, co1);
		mul_m4_v3(imat, co2);
		min_d=2.0;
		
		/* warning, returns the derived mesh face */
		if (particle_intersect_dm(scene, ob, dm, 0, co1, co2, &min_d, &add_pars[n].num_dmcache, add_pars[n].fuv, 0, 0, 0, 0)) {
			if (psys->part->use_modifier_stack && !psmd->dm_final->deformedOnly) {
				add_pars[n].num = add_pars[n].num_dmcache;
				add_pars[n].num_dmcache = DMCACHE_ISCHILD;
			}
			else if (dm == psmd->dm_deformed) {
				/* Final DM is not same topology as orig mesh, we have to map num_dmcache to real final dm. */
				add_pars[n].num = add_pars[n].num_dmcache;
				add_pars[n].num_dmcache = psys_particle_dm_face_lookup(
				                              psmd->dm_final, psmd->dm_deformed,
				                              add_pars[n].num, add_pars[n].fuv, NULL);
			}
			else {
				add_pars[n].num = add_pars[n].num_dmcache;
			}

			if (add_pars[n].num != DMCACHE_NOTFOUND) {
				n++;
			}
		}
	}
	if (n) {
		int newtotpart=totpart+n;
		float hairmat[4][4], cur_co[3];
		KDTree *tree=0;
		ParticleData *pa, *new_pars = MEM_callocN(newtotpart*sizeof(ParticleData), "ParticleData new");
		PTCacheEditPoint *point, *new_points = MEM_callocN(newtotpart*sizeof(PTCacheEditPoint), "PTCacheEditPoint array new");
		PTCacheEditKey *key;
		HairKey *hkey;

		/* save existing elements */
		memcpy(new_pars, psys->particles, totpart * sizeof(ParticleData));
		memcpy(new_points, edit->points, totpart * sizeof(PTCacheEditPoint));

		/* change old arrays to new ones */
		if (psys->particles) MEM_freeN(psys->particles);
		psys->particles= new_pars;

		if (edit->points) MEM_freeN(edit->points);
		edit->points= new_points;

		if (edit->mirror_cache) {
			MEM_freeN(edit->mirror_cache);
			edit->mirror_cache= NULL;
		}

		/* create tree for interpolation */
		if (pset->flag & PE_INTERPOLATE_ADDED && psys->totpart) {
			tree=BLI_kdtree_new(psys->totpart);
			
			for (i=0, pa=psys->particles; i<totpart; i++, pa++) {
				psys_particle_on_dm(psmd->dm_final, psys->part->from, pa->num, pa->num_dmcache, pa->fuv, pa->foffset, cur_co, 0, 0, 0, 0, 0);
				BLI_kdtree_insert(tree, i, cur_co);
			}

			BLI_kdtree_balance(tree);
		}

		edit->totpoint= psys->totpart= newtotpart;

		/* create new elements */
		pa = psys->particles + totpart;
		point = edit->points + totpart;

		for (i=totpart; i<newtotpart; i++, pa++, point++) {
			memcpy(pa, add_pars + i - totpart, sizeof(ParticleData));
			pa->hair= MEM_callocN(pset->totaddkey * sizeof(HairKey), "BakeKey key add");
			key= point->keys= MEM_callocN(pset->totaddkey * sizeof(PTCacheEditKey), "PTCacheEditKey add");
			point->totkey= pa->totkey= pset->totaddkey;

			for (k=0, hkey=pa->hair; k<pa->totkey; k++, hkey++, key++) {
				key->co= hkey->co;
				key->time= &hkey->time;

				if (!(psys->flag & PSYS_GLOBAL_HAIR))
					key->flag |= PEK_USE_WCO;
			}
			
			pa->size= 1.0f;
			initialize_particle(&sim, pa);
			reset_particle(&sim, pa, 0.0, 1.0);
			point->flag |= PEP_EDIT_RECALC;
			if (pe_x_mirror(ob))
				point->flag |= PEP_TAG; /* signal for duplicate */
			
			framestep= pa->lifetime/(float)(pset->totaddkey-1);

			if (tree) {
				ParticleData *ppa;
				HairKey *thkey;
				ParticleKey key3[3];
				KDTreeNearest ptn[3];
				int w, maxw;
				float maxd, totw=0.0, weight[3];

				psys_particle_on_dm(psmd->dm_final, psys->part->from, pa->num, pa->num_dmcache, pa->fuv, pa->foffset, co1, 0, 0, 0, 0, 0);
				maxw = BLI_kdtree_find_nearest_n(tree, co1, ptn, 3);

				maxd= ptn[maxw-1].dist;
				
				for (w=0; w<maxw; w++) {
					weight[w] = (float)pow(2.0, (double)(-6.0f * ptn[w].dist / maxd));
					totw += weight[w];
				}
				for (;w<3; w++) {
					weight[w] = 0.0f;
				}

				if (totw > 0.0f) {
					for (w=0; w<maxw; w++)
						weight[w] /= totw;
				}
				else {
					for (w=0; w<maxw; w++)
						weight[w] = 1.0f/maxw;
				}

				ppa= psys->particles+ptn[0].index;

				for (k=0; k<pset->totaddkey; k++) {
					thkey= (HairKey *)pa->hair + k;
					thkey->time= pa->time + k * framestep;

					key3[0].time= thkey->time/ 100.0f;
					psys_get_particle_on_path(&sim, ptn[0].index, key3, 0);
					mul_v3_fl(key3[0].co, weight[0]);
					
					/* TODO: interpolating the weight would be nicer */
					thkey->weight= (ppa->hair+MIN2(k, ppa->totkey-1))->weight;
					
					if (maxw>1) {
						key3[1].time= key3[0].time;
						psys_get_particle_on_path(&sim, ptn[1].index, &key3[1], 0);
						mul_v3_fl(key3[1].co, weight[1]);
						add_v3_v3(key3[0].co, key3[1].co);

						if (maxw>2) {
							key3[2].time= key3[0].time;
							psys_get_particle_on_path(&sim, ptn[2].index, &key3[2], 0);
							mul_v3_fl(key3[2].co, weight[2]);
							add_v3_v3(key3[0].co, key3[2].co);
						}
					}

					if (k==0)
						sub_v3_v3v3(co1, pa->state.co, key3[0].co);

					add_v3_v3v3(thkey->co, key3[0].co, co1);

					thkey->time= key3[0].time;
				}
			}
			else {
				for (k=0, hkey=pa->hair; k<pset->totaddkey; k++, hkey++) {
					madd_v3_v3v3fl(hkey->co, pa->state.co, pa->state.vel, k * framestep * timestep);
					hkey->time += k * framestep;
					hkey->weight = 1.f - (float)k/(float)(pset->totaddkey-1);
				}
			}
			for (k=0, hkey=pa->hair; k<pset->totaddkey; k++, hkey++) {
				psys_mat_hair_to_global(ob, psmd->dm_final, psys->part->from, pa, hairmat);
				invert_m4_m4(imat, hairmat);
				mul_m4_v3(imat, hkey->co);
			}
		}

		if (tree)
			BLI_kdtree_free(tree);
	}

	MEM_freeN(add_pars);

	BLI_rng_free(rng);
	
	return n;
}

/************************* brush edit operator ********************/

typedef struct BrushEdit {
	Scene *scene;
	Object *ob;
	PTCacheEdit *edit;

	int first;
	int lastmouse[2];
	float zfac;

	/* optional cached view settings to avoid setting on every mousemove */
	PEData data;
} BrushEdit;

static int brush_edit_init(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	ParticleEditSettings *pset= PE_settings(scene);
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ARegion *ar= CTX_wm_region(C);
	BrushEdit *bedit;
	float min[3], max[3];
	
	if (pset->brushtype < 0)
		return 0;

	/* set the 'distance factor' for grabbing (used in comb etc) */
	INIT_MINMAX(min, max);
	PE_minmax(scene, min, max);
	mid_v3_v3v3(min, min, max);

	bedit= MEM_callocN(sizeof(BrushEdit), "BrushEdit");
	bedit->first= 1;
	op->customdata= bedit;

	bedit->scene= scene;
	bedit->ob= ob;
	bedit->edit= edit;

	bedit->zfac = ED_view3d_calc_zfac(ar->regiondata, min, NULL);

	/* cache view depths and settings for re-use */
	PE_set_view3d_data(C, &bedit->data);

	return 1;
}

static void brush_edit_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
{
	BrushEdit *bedit= op->customdata;
	Scene *scene= bedit->scene;
	Object *ob= bedit->ob;
	PTCacheEdit *edit= bedit->edit;
	ParticleEditSettings *pset= PE_settings(scene);
	ParticleSystemModifierData *psmd= edit->psys ? psys_get_modifier(ob, edit->psys) : NULL;
	ParticleBrushData *brush= &pset->brush[pset->brushtype];
	ARegion *ar= CTX_wm_region(C);
	float vec[3], mousef[2];
	int mval[2];
	int flip, mouse[2], removed= 0, added=0, selected= 0, tot_steps= 1, step= 1;
	float dx, dy, dmax;
	int lock_root = pset->flag & PE_LOCK_FIRST;

	if (!PE_start_edit(edit))
		return;

	RNA_float_get_array(itemptr, "mouse", mousef);
	mouse[0] = mousef[0];
	mouse[1] = mousef[1];
	flip= RNA_boolean_get(itemptr, "pen_flip");

	if (bedit->first) {
		bedit->lastmouse[0] = mouse[0];
		bedit->lastmouse[1] = mouse[1];
	}

	dx= mouse[0] - bedit->lastmouse[0];
	dy= mouse[1] - bedit->lastmouse[1];

	mval[0] = mouse[0];
	mval[1] = mouse[1];


	/* disable locking temporatily for disconnected hair */
	if (edit->psys && edit->psys->flag & PSYS_GLOBAL_HAIR)
		pset->flag &= ~PE_LOCK_FIRST;

	if (((pset->brushtype == PE_BRUSH_ADD) ?
	     (sqrtf(dx * dx + dy * dy) > pset->brush[PE_BRUSH_ADD].step) : (dx != 0 || dy != 0)) || bedit->first)
	{
		PEData data= bedit->data;

		view3d_operator_needs_opengl(C);
		selected= (short)count_selected_keys(scene, edit);

		dmax = max_ff(fabsf(dx), fabsf(dy));
		tot_steps = dmax/(0.2f * pe_brush_size_get(scene, brush)) + 1;

		dx /= (float)tot_steps;
		dy /= (float)tot_steps;

		for (step = 1; step<=tot_steps; step++) {
			mval[0] = bedit->lastmouse[0] + step*dx;
			mval[1] = bedit->lastmouse[1] + step*dy;

			switch (pset->brushtype) {
				case PE_BRUSH_COMB:
				{
					const float mval_f[2] = {dx, dy};
					data.mval= mval;
					data.rad= pe_brush_size_get(scene, brush);

					data.combfac= (brush->strength - 0.5f) * 2.0f;
					if (data.combfac < 0.0f)
						data.combfac= 1.0f - 9.0f * data.combfac;
					else
						data.combfac= 1.0f - data.combfac;

					invert_m4_m4(ob->imat, ob->obmat);

					ED_view3d_win_to_delta(ar, mval_f, vec, bedit->zfac);
					data.dvec= vec;

					foreach_mouse_hit_key(&data, brush_comb, selected);
					break;
				}
				case PE_BRUSH_CUT:
				{
					if (edit->psys && edit->pathcache) {
						data.mval= mval;
						data.rad= pe_brush_size_get(scene, brush);
						data.cutfac= brush->strength;

						if (selected)
							foreach_selected_point(&data, brush_cut);
						else
							foreach_point(&data, brush_cut);

						removed= remove_tagged_particles(ob, edit->psys, pe_x_mirror(ob));
						if (pset->flag & PE_KEEP_LENGTHS)
							recalc_lengths(edit);
					}
					else
						removed= 0;

					break;
				}
				case PE_BRUSH_LENGTH:
				{
					data.mval= mval;
				
					data.rad= pe_brush_size_get(scene, brush);
					data.growfac= brush->strength / 50.0f;

					if (brush->invert ^ flip)
						data.growfac= 1.0f - data.growfac;
					else
						data.growfac= 1.0f + data.growfac;

					foreach_mouse_hit_point(&data, brush_length, selected);

					if (pset->flag & PE_KEEP_LENGTHS)
						recalc_lengths(edit);
					break;
				}
				case PE_BRUSH_PUFF:
				{
					if (edit->psys) {
						data.dm= psmd->dm_final;
						data.mval= mval;
						data.rad= pe_brush_size_get(scene, brush);
						data.select= selected;

						data.pufffac= (brush->strength - 0.5f) * 2.0f;
						if (data.pufffac < 0.0f)
							data.pufffac= 1.0f - 9.0f * data.pufffac;
						else
							data.pufffac= 1.0f - data.pufffac;

						data.invert= (brush->invert ^ flip);
						invert_m4_m4(ob->imat, ob->obmat);

						foreach_mouse_hit_point(&data, brush_puff, selected);
					}
					break;
				}
				case PE_BRUSH_ADD:
				{
					if (edit->psys && edit->psys->part->from==PART_FROM_FACE) {
						data.mval= mval;

						added= brush_add(&data, brush->count);

						if (pset->flag & PE_KEEP_LENGTHS)
							recalc_lengths(edit);
					}
					else
						added= 0;
					break;
				}
				case PE_BRUSH_SMOOTH:
				{
					data.mval= mval;
					data.rad= pe_brush_size_get(scene, brush);

					data.vec[0] = data.vec[1] = data.vec[2] = 0.0f;
					data.tot= 0;

					data.smoothfac= brush->strength;

					invert_m4_m4(ob->imat, ob->obmat);

					foreach_mouse_hit_key(&data, brush_smooth_get, selected);

					if (data.tot) {
						mul_v3_fl(data.vec, 1.0f / (float)data.tot);
						foreach_mouse_hit_key(&data, brush_smooth_do, selected);
					}

					break;
				}
				case PE_BRUSH_WEIGHT:
				{
					if (edit->psys) {
						data.dm= psmd->dm_final;
						data.mval= mval;
						data.rad= pe_brush_size_get(scene, brush);

						data.weightfac = brush->strength; /* note that this will never be zero */

						foreach_mouse_hit_key(&data, BKE_brush_weight_get, selected);
					}

					break;
				}
			}
			if ((pset->flag & PE_KEEP_LENGTHS)==0)
				recalc_lengths(edit);

			if (ELEM(pset->brushtype, PE_BRUSH_ADD, PE_BRUSH_CUT) && (added || removed)) {
				if (pset->brushtype == PE_BRUSH_ADD && pe_x_mirror(ob))
					PE_mirror_x(scene, ob, 1);

				update_world_cos(ob, edit);
				psys_free_path_cache(NULL, edit);
				DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
			}
			else
				PE_update_object(scene, ob, 1);
		}

		if (edit->psys) {
			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
		}
		else {
			DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
			WM_event_add_notifier(C, NC_OBJECT|ND_MODIFIER, ob);
		}

		bedit->lastmouse[0] = mouse[0];
		bedit->lastmouse[1] = mouse[1];
		bedit->first= 0;
	}

	pset->flag |= lock_root;
}

static void brush_edit_exit(wmOperator *op)
{
	BrushEdit *bedit= op->customdata;

	MEM_freeN(bedit);
}

static int brush_edit_exec(bContext *C, wmOperator *op)
{
	if (!brush_edit_init(C, op))
		return OPERATOR_CANCELLED;

	RNA_BEGIN (op->ptr, itemptr, "stroke")
	{
		brush_edit_apply(C, op, &itemptr);
	}
	RNA_END;

	brush_edit_exit(op);

	return OPERATOR_FINISHED;
}

static void brush_edit_apply_event(bContext *C, wmOperator *op, const wmEvent *event)
{
	PointerRNA itemptr;
	float mouse[2];

	VECCOPY2D(mouse, event->mval);

	/* fill in stroke */
	RNA_collection_add(op->ptr, "stroke", &itemptr);

	RNA_float_set_array(&itemptr, "mouse", mouse);
	RNA_boolean_set(&itemptr, "pen_flip", event->shift != false); // XXX hardcoded

	/* apply */
	brush_edit_apply(C, op, &itemptr);
}

static int brush_edit_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
	if (!brush_edit_init(C, op))
		return OPERATOR_CANCELLED;
	
	brush_edit_apply_event(C, op, event);

	WM_event_add_modal_handler(C, op);

	return OPERATOR_RUNNING_MODAL;
}

static int brush_edit_modal(bContext *C, wmOperator *op, const wmEvent *event)
{
	switch (event->type) {
		case LEFTMOUSE:
		case MIDDLEMOUSE:
		case RIGHTMOUSE: // XXX hardcoded
			brush_edit_exit(op);
			return OPERATOR_FINISHED;
		case MOUSEMOVE:
			brush_edit_apply_event(C, op, event);
			break;
	}

	return OPERATOR_RUNNING_MODAL;
}

static void brush_edit_cancel(bContext *UNUSED(C), wmOperator *op)
{
	brush_edit_exit(op);
}

void PARTICLE_OT_brush_edit(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Brush Edit";
	ot->idname = "PARTICLE_OT_brush_edit";
	ot->description = "Apply a stroke of brush to the particles";
	
	/* api callbacks */
	ot->exec = brush_edit_exec;
	ot->invoke = brush_edit_invoke;
	ot->modal = brush_edit_modal;
	ot->cancel = brush_edit_cancel;
	ot->poll = PE_poll_view3d;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO|OPTYPE_BLOCKING;

	/* properties */
	RNA_def_collection_runtime(ot->srna, "stroke", &RNA_OperatorStrokeElement, "Stroke", "");
}

/*********************** cut shape ***************************/

static int shape_cut_poll(bContext *C)
{
	if (PE_hair_poll(C)) {
		Scene *scene = CTX_data_scene(C);
		ParticleEditSettings *pset = PE_settings(scene);
		
		if (pset->shape_object && (pset->shape_object->type == OB_MESH)) {
			return true;
		}
	}
	
	return false;
}

typedef struct PointInsideBVH {
	BVHTreeFromMesh bvhdata;
	int num_hits;
} PointInsideBVH;

static void point_inside_bvh_cb(void *userdata, int index, const BVHTreeRay *ray, BVHTreeRayHit *hit)
{
	PointInsideBVH *data = userdata;
	
	data->bvhdata.raycast_callback(&data->bvhdata, index, ray, hit);
	
	if (hit->index != -1)
		++data->num_hits;
}

/* true if the point is inside the shape mesh */
static bool shape_cut_test_point(PEData *data, ParticleCacheKey *key)
{
	BVHTreeFromMesh *shape_bvh = &data->shape_bvh;
	const float dir[3] = {1.0f, 0.0f, 0.0f};
	PointInsideBVH userdata;
	
	userdata.bvhdata = data->shape_bvh;
	userdata.num_hits = 0;
	
	BLI_bvhtree_ray_cast_all(
	        shape_bvh->tree, key->co, dir, 0.0f, BVH_RAYCAST_DIST_MAX,
	        point_inside_bvh_cb, &userdata);
	
	/* for any point inside a watertight mesh the number of hits is uneven */
	return (userdata.num_hits % 2) == 1;
}

static void shape_cut(PEData *data, int pa_index)
{
	PTCacheEdit *edit = data->edit;
	Object *ob = data->ob;
	ParticleEditSettings *pset = PE_settings(data->scene);
	ParticleCacheKey *key;
	
	bool cut;
	float cut_time = 1.0;
	int k, totkeys = 1 << pset->draw_step;
	
	/* don't cut hidden */
	if (edit->points[pa_index].flag & PEP_HIDE)
		return;
	
	cut = false;
	
	/* check if root is inside the cut shape */
	key = edit->pathcache[pa_index];
	if (!shape_cut_test_point(data, key)) {
		cut_time = -1.0f;
		cut = true;
	}
	else {
		for (k = 0; k < totkeys; k++, key++) {
			BVHTreeRayHit hit;
			float dir[3];
			float len;
			
			sub_v3_v3v3(dir, (key+1)->co, key->co);
			len = normalize_v3(dir);
			
			memset(&hit, 0, sizeof(hit));
			hit.index = -1;
			hit.dist = len;
			BLI_bvhtree_ray_cast(data->shape_bvh.tree, key->co, dir, 0.0f, &hit, data->shape_bvh.raycast_callback, &data->shape_bvh);
			if (hit.index >= 0) {
				if (hit.dist < len) {
					cut_time = (hit.dist / len + (float)k) / (float)totkeys;
					cut = true;
					break;
				}
			}
		}
	}

	if (cut) {
		if (cut_time < 0.0f) {
			edit->points[pa_index].flag |= PEP_TAG;
		}
		else {
			rekey_particle_to_time(data->scene, ob, pa_index, cut_time);
			edit->points[pa_index].flag |= PEP_EDIT_RECALC;
		}
	}
}

static int shape_cut_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Object *ob = CTX_data_active_object(C);
	ParticleEditSettings *pset = PE_settings(scene);
	PTCacheEdit *edit = PE_get_current(scene, ob);
	Object *shapeob = pset->shape_object;
	int selected = count_selected_keys(scene, edit);
	int lock_root = pset->flag & PE_LOCK_FIRST;
	
	if (!PE_start_edit(edit))
		return OPERATOR_CANCELLED;
	
	/* disable locking temporatily for disconnected hair */
	if (edit->psys && edit->psys->flag & PSYS_GLOBAL_HAIR)
		pset->flag &= ~PE_LOCK_FIRST;
	
	if (edit->psys && edit->pathcache) {
		PEData data;
		int removed;
		
		PE_set_data(C, &data);
		if (!PE_create_shape_tree(&data, shapeob)) {
			/* shapeob may not have faces... */
			return OPERATOR_CANCELLED;
		}
		
		if (selected)
			foreach_selected_point(&data, shape_cut);
		else
			foreach_point(&data, shape_cut);
		
		removed = remove_tagged_particles(ob, edit->psys, pe_x_mirror(ob));
		recalc_lengths(edit);
		
		if (removed) {
			update_world_cos(ob, edit);
			psys_free_path_cache(NULL, edit);
			DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
		}
		else
			PE_update_object(scene, ob, 1);
		
		if (edit->psys) {
			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
		}
		else {
			DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
			WM_event_add_notifier(C, NC_OBJECT|ND_MODIFIER, ob);
		}
		
		PE_free_shape_tree(&data);
	}
	
	pset->flag |= lock_root;
	
	return OPERATOR_FINISHED;
}

void PARTICLE_OT_shape_cut(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Shape Cut";
	ot->idname = "PARTICLE_OT_shape_cut";
	ot->description = "Cut hair to conform to the set shape object";
	
	/* api callbacks */
	ot->exec = shape_cut_exec;
	ot->poll = shape_cut_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/*********************** undo ***************************/

static void free_PTCacheUndo(PTCacheUndo *undo)
{
	PTCacheEditPoint *point;
	int i;

	for (i=0, point=undo->points; i<undo->totpoint; i++, point++) {
		if (undo->particles && (undo->particles + i)->hair)
			MEM_freeN((undo->particles + i)->hair);
		if (point->keys)
			MEM_freeN(point->keys);
	}
	if (undo->points)
		MEM_freeN(undo->points);

	if (undo->particles)
		MEM_freeN(undo->particles);

	BKE_ptcache_free_mem(&undo->mem_cache);
}

static void make_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
{
	PTCacheEditPoint *point;
	int i;

	undo->totpoint= edit->totpoint;

	if (edit->psys) {
		ParticleData *pa;

		pa= undo->particles= MEM_dupallocN(edit->psys->particles);

		for (i=0; i<edit->totpoint; i++, pa++)
			pa->hair= MEM_dupallocN(pa->hair);

		undo->psys_flag = edit->psys->flag;
	}
	else {
		PTCacheMem *pm;

		BLI_duplicatelist(&undo->mem_cache, &edit->pid.cache->mem_cache);
		pm = undo->mem_cache.first;

		for (; pm; pm=pm->next) {
			for (i=0; i<BPHYS_TOT_DATA; i++)
				pm->data[i] = MEM_dupallocN(pm->data[i]);
		}
	}

	point= undo->points = MEM_dupallocN(edit->points);
	undo->totpoint = edit->totpoint;

	for (i=0; i<edit->totpoint; i++, point++) {
		point->keys= MEM_dupallocN(point->keys);
		/* no need to update edit key->co & key->time pointers here */
	}
}

static void get_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
{
	ParticleSystem *psys = edit->psys;
	ParticleData *pa;
	HairKey *hkey;
	POINT_P; KEY_K;

	LOOP_POINTS {
		if (psys && psys->particles[p].hair)
			MEM_freeN(psys->particles[p].hair);

		if (point->keys)
			MEM_freeN(point->keys);
	}
	if (psys && psys->particles)
		MEM_freeN(psys->particles);
	if (edit->points)
		MEM_freeN(edit->points);
	if (edit->mirror_cache) {
		MEM_freeN(edit->mirror_cache);
		edit->mirror_cache= NULL;
	}

	edit->points= MEM_dupallocN(undo->points);
	edit->totpoint = undo->totpoint;

	LOOP_POINTS {
		point->keys= MEM_dupallocN(point->keys);
	}

	if (psys) {
		psys->particles= MEM_dupallocN(undo->particles);

		psys->totpart= undo->totpoint;

		LOOP_POINTS {
			pa = psys->particles + p;
			hkey= pa->hair = MEM_dupallocN(pa->hair);

			LOOP_KEYS {
				key->co= hkey->co;
				key->time= &hkey->time;
				hkey++;
			}
		}

		psys->flag = undo->psys_flag;
	}
	else {
		PTCacheMem *pm;
		int i;

		BKE_ptcache_free_mem(&edit->pid.cache->mem_cache);

		BLI_duplicatelist(&edit->pid.cache->mem_cache, &undo->mem_cache);

		pm = edit->pid.cache->mem_cache.first;

		for (; pm; pm=pm->next) {
			for (i=0; i<BPHYS_TOT_DATA; i++)
				pm->data[i] = MEM_dupallocN(pm->data[i]);

			BKE_ptcache_mem_pointers_init(pm);

			LOOP_POINTS {
				LOOP_KEYS {
					if ((int)key->ftime == (int)pm->frame) {
						key->co = pm->cur[BPHYS_DATA_LOCATION];
						key->vel = pm->cur[BPHYS_DATA_VELOCITY];
						key->rot = pm->cur[BPHYS_DATA_ROTATION];
						key->time = &key->ftime;
					}
				}
				BKE_ptcache_mem_pointers_incr(pm);
			}
		}
	}
}

void PE_undo_push(Scene *scene, const char *str)
{
	PTCacheEdit *edit= PE_get_current(scene, OBACT);
	PTCacheUndo *undo;
	int nr;

	if (!edit) return;

	/* remove all undos after (also when curundo==NULL) */
	while (edit->undo.last != edit->curundo) {
		undo= edit->undo.last;
		BLI_remlink(&edit->undo, undo);
		free_PTCacheUndo(undo);
		MEM_freeN(undo);
	}

	/* make new */
	edit->curundo= undo= MEM_callocN(sizeof(PTCacheUndo), "particle undo file");
	BLI_strncpy(undo->name, str, sizeof(undo->name));
	BLI_addtail(&edit->undo, undo);
	
	/* and limit amount to the maximum */
	nr= 0;
	undo= edit->undo.last;
	while (undo) {
		nr++;
		if (nr==U.undosteps) break;
		undo= undo->prev;
	}
	if (undo) {
		while (edit->undo.first != undo) {
			PTCacheUndo *first= edit->undo.first;
			BLI_remlink(&edit->undo, first);
			free_PTCacheUndo(first);
			MEM_freeN(first);
		}
	}

	/* copy  */
	make_PTCacheUndo(edit, edit->curundo);
}

void PE_undo_step(Scene *scene, int step)
{	
	PTCacheEdit *edit= PE_get_current(scene, OBACT);

	if (!edit) return;

	if (step==0) {
		get_PTCacheUndo(edit, edit->curundo);
	}
	else if (step==1) {
		
		if (edit->curundo==NULL || edit->curundo->prev==NULL) {
			/* pass */
		}
		else {
			if (G.debug & G_DEBUG) printf("undo %s\n", edit->curundo->name);
			edit->curundo= edit->curundo->prev;
			get_PTCacheUndo(edit, edit->curundo);
		}
	}
	else {
		/* curundo has to remain current situation! */
		
		if (edit->curundo==NULL || edit->curundo->next==NULL) {
			/* pass */
		}
		else {
			get_PTCacheUndo(edit, edit->curundo->next);
			edit->curundo= edit->curundo->next;
			if (G.debug & G_DEBUG) printf("redo %s\n", edit->curundo->name);
		}
	}

	DAG_id_tag_update(&OBACT->id, OB_RECALC_DATA);
}

bool PE_undo_is_valid(Scene *scene)
{
	PTCacheEdit *edit= PE_get_current(scene, OBACT);
	
	if (edit) {
		return (edit->undo.last != edit->undo.first);
	}
	return 0;
}

void PTCacheUndo_clear(PTCacheEdit *edit)
{
	PTCacheUndo *undo;

	if (edit==NULL) return;
	
	undo= edit->undo.first;
	while (undo) {
		free_PTCacheUndo(undo);
		undo= undo->next;
	}
	BLI_freelistN(&edit->undo);
	edit->curundo= NULL;
}

void PE_undo(Scene *scene)
{
	PE_undo_step(scene, 1);
}

void PE_redo(Scene *scene)
{
	PE_undo_step(scene, -1);
}

void PE_undo_number(Scene *scene, int nr)
{
	PTCacheEdit *edit= PE_get_current(scene, OBACT);
	PTCacheUndo *undo;
	int a=0;
	
	for (undo= edit->undo.first; undo; undo= undo->next, a++) {
		if (a==nr) break;
	}
	edit->curundo= undo;
	PE_undo_step(scene, 0);
}


/* get name of undo item, return null if no item with this index */
/* if active pointer, set it to 1 if true */
const char *PE_undo_get_name(Scene *scene, int nr, bool *r_active)
{
	PTCacheEdit *edit= PE_get_current(scene, OBACT);
	PTCacheUndo *undo;
	
	if (r_active) *r_active = false;
	
	if (edit) {
		undo= BLI_findlink(&edit->undo, nr);
		if (undo) {
			if (r_active && (undo == edit->curundo)) {
				*r_active = true;
			}
			return undo->name;
		}
	}
	return NULL;
}

/************************ utilities ******************************/

int PE_minmax(Scene *scene, float min[3], float max[3])
{
	Object *ob= OBACT;
	PTCacheEdit *edit= PE_get_current(scene, ob);
	ParticleSystem *psys;
	ParticleSystemModifierData *psmd = NULL;
	POINT_P; KEY_K;
	float co[3], mat[4][4];
	int ok= 0;

	if (!edit) return ok;

	if ((psys = edit->psys))
		psmd= psys_get_modifier(ob, psys);
	else
		unit_m4(mat);

	LOOP_VISIBLE_POINTS {
		if (psys)
			psys_mat_hair_to_global(ob, psmd->dm_final, psys->part->from, psys->particles+p, mat);

		LOOP_SELECTED_KEYS {
			copy_v3_v3(co, key->co);
			mul_m4_v3(mat, co);
			DO_MINMAX(co, min, max);
			ok= 1;
		}
	}

	if (!ok) {
		BKE_object_minmax(ob, min, max, true);
		ok= 1;
	}

	return ok;
}

/************************ particle edit toggle operator ************************/

/* initialize needed data for bake edit */
void PE_create_particle_edit(Scene *scene, Object *ob, PointCache *cache, ParticleSystem *psys)
{
	PTCacheEdit *edit;
	ParticleSystemModifierData *psmd = (psys) ? psys_get_modifier(ob, psys) : NULL;
	POINT_P; KEY_K;
	ParticleData *pa = NULL;
	HairKey *hkey;
	int totpoint;

	/* no psmd->dm happens in case particle system modifier is not enabled */
	if (!(psys && psmd && psmd->dm_final) && !cache)
		return;

	if (cache && cache->flag & PTCACHE_DISK_CACHE)
		return;

	if (psys == NULL && (cache && BLI_listbase_is_empty(&cache->mem_cache)))
		return;

	edit = (psys) ? psys->edit : cache->edit;

	if (!edit) {
		totpoint = psys ? psys->totpart : (int)((PTCacheMem *)cache->mem_cache.first)->totpoint;

		edit= MEM_callocN(sizeof(PTCacheEdit), "PE_create_particle_edit");
		edit->points=MEM_callocN(totpoint*sizeof(PTCacheEditPoint), "PTCacheEditPoints");
		edit->totpoint = totpoint;

		if (psys && !cache) {
			psys->edit= edit;
			edit->psys = psys;

			psys->free_edit= PE_free_ptcache_edit;

			edit->pathcache = NULL;
			BLI_listbase_clear(&edit->pathcachebufs);

			pa = psys->particles;
			LOOP_POINTS {
				point->totkey = pa->totkey;
				point->keys= MEM_callocN(point->totkey*sizeof(PTCacheEditKey), "ParticleEditKeys");
				point->flag |= PEP_EDIT_RECALC;

				hkey = pa->hair;
				LOOP_KEYS {
					key->co= hkey->co;
					key->time= &hkey->time;
					key->flag= hkey->editflag;
					if (!(psys->flag & PSYS_GLOBAL_HAIR)) {
						key->flag |= PEK_USE_WCO;
						hkey->editflag |= PEK_USE_WCO;
					}

					hkey++;
				}
				pa++;
			}
			update_world_cos(ob, edit);
		}
		else {
			PTCacheMem *pm;
			int totframe=0;

			cache->edit= edit;
			cache->free_edit= PE_free_ptcache_edit;
			edit->psys = NULL;

			for (pm=cache->mem_cache.first; pm; pm=pm->next)
				totframe++;

			for (pm=cache->mem_cache.first; pm; pm=pm->next) {
				LOOP_POINTS {
					if (BKE_ptcache_mem_pointers_seek(p, pm) == 0)
						continue;

					if (!point->totkey) {
						key = point->keys = MEM_callocN(totframe*sizeof(PTCacheEditKey), "ParticleEditKeys");
						point->flag |= PEP_EDIT_RECALC;
					}
					else
						key = point->keys + point->totkey;

					key->co = pm->cur[BPHYS_DATA_LOCATION];
					key->vel = pm->cur[BPHYS_DATA_VELOCITY];
					key->rot = pm->cur[BPHYS_DATA_ROTATION];
					key->ftime = (float)pm->frame;
					key->time = &key->ftime;
					BKE_ptcache_mem_pointers_incr(pm);

					point->totkey++;
				}
			}
			psys = NULL;
		}

		UI_GetThemeColor3ubv(TH_EDGE_SELECT, edit->sel_col);
		UI_GetThemeColor3ubv(TH_WIRE, edit->nosel_col);

		recalc_lengths(edit);
		if (psys && !cache)
			recalc_emitter_field(ob, psys);
		PE_update_object(scene, ob, 1);

		PTCacheUndo_clear(edit);
		PE_undo_push(scene, "Original");
	}
}

static int particle_edit_toggle_poll(bContext *C)
{
	Object *ob = CTX_data_active_object(C);

	if (ob == NULL || ob->type != OB_MESH)
		return 0;
	if (!ob->data || ID_IS_LINKED_DATABLOCK(ob->data))
		return 0;
	if (CTX_data_edit_object(C))
		return 0;

	return (ob->particlesystem.first ||
	        modifiers_findByType(ob, eModifierType_Cloth) ||
	        modifiers_findByType(ob, eModifierType_Softbody));
}

static int particle_edit_toggle_exec(bContext *C, wmOperator *op)
{
	Scene *scene = CTX_data_scene(C);
	Object *ob = CTX_data_active_object(C);
	const int mode_flag = OB_MODE_PARTICLE_EDIT;
	const bool is_mode_set = (ob->mode & mode_flag) != 0;

	if (!is_mode_set) {
		if (!ED_object_mode_compat_set(C, ob, mode_flag, op->reports)) {
			return OPERATOR_CANCELLED;
		}
	}

	if (!is_mode_set) {
		PTCacheEdit *edit;
		ob->mode |= mode_flag;
		edit= PE_create_current(scene, ob);
	
		/* mesh may have changed since last entering editmode.
		 * note, this may have run before if the edit data was just created, so could avoid this and speed up a little */
		if (edit && edit->psys)
			recalc_emitter_field(ob, edit->psys);
		
		toggle_particle_cursor(C, 1);
		WM_event_add_notifier(C, NC_SCENE|ND_MODE|NS_MODE_PARTICLE, NULL);
	}
	else {
		ob->mode &= ~mode_flag;
		toggle_particle_cursor(C, 0);
		WM_event_add_notifier(C, NC_SCENE|ND_MODE|NS_MODE_OBJECT, NULL);
	}

	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_particle_edit_toggle(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Particle Edit Toggle";
	ot->idname = "PARTICLE_OT_particle_edit_toggle";
	ot->description = "Toggle particle edit mode";
	
	/* api callbacks */
	ot->exec = particle_edit_toggle_exec;
	ot->poll = particle_edit_toggle_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}


/************************ set editable operator ************************/

static int clear_edited_exec(bContext *C, wmOperator *UNUSED(op))
{
	Object *ob= CTX_data_active_object(C);
	ParticleSystem *psys = psys_get_current(ob);
	
	if (psys->edit) {
		if (psys->edit->edited || 1) {
			PE_free_ptcache_edit(psys->edit);

			psys->edit = NULL;
			psys->free_edit = NULL;

			psys->recalc |= PSYS_RECALC_RESET;
			psys->flag &= ~PSYS_GLOBAL_HAIR;
			psys->flag &= ~PSYS_EDITED;

			psys_reset(psys, PSYS_RESET_DEPSGRAPH);
			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
			DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
		}
	}
	else { /* some operation might have protected hair from editing so let's clear the flag */
		psys->recalc |= PSYS_RECALC_RESET;
		psys->flag &= ~PSYS_GLOBAL_HAIR;
		psys->flag &= ~PSYS_EDITED;
		WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
		DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
	}

	return OPERATOR_FINISHED;
}

static int clear_edited_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
{
	return WM_operator_confirm_message(C, op, "Lose changes done in particle mode? (no undo)");
}

void PARTICLE_OT_edited_clear(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Clear Edited";
	ot->idname = "PARTICLE_OT_edited_clear";
	ot->description = "Undo all edition performed on the particle system";
	
	/* api callbacks */
	ot->exec = clear_edited_exec;
	ot->poll = particle_edit_toggle_poll;
	ot->invoke = clear_edited_invoke;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************************ Unify length operator ************************/

static float calculate_point_length(PTCacheEditPoint *point)
{
	float length = 0.0f;
	KEY_K;
	LOOP_KEYS {
		if (k > 0) {
			length += len_v3v3((key - 1)->co, key->co);
		}
	}
	return length;
}

static float calculate_average_length(PTCacheEdit *edit)
{
	int num_selected = 0;
	float total_length = 0;
	POINT_P;
	LOOP_SELECTED_POINTS {
		total_length += calculate_point_length(point);
		++num_selected;
	}
	if (num_selected == 0) {
		return 0.0f;
	}
	return total_length / num_selected;
}

static void scale_point_factor(PTCacheEditPoint *point, float factor)
{
	float orig_prev_co[3], prev_co[3];
	KEY_K;
	LOOP_KEYS {
		if (k == 0) {
			copy_v3_v3(orig_prev_co, key->co);
			copy_v3_v3(prev_co, key->co);
		}
		else {
			float new_co[3];
			float delta[3];

			sub_v3_v3v3(delta, key->co, orig_prev_co);
			mul_v3_fl(delta, factor);
			add_v3_v3v3(new_co, prev_co, delta);

			copy_v3_v3(orig_prev_co, key->co);
			copy_v3_v3(key->co, new_co);
			copy_v3_v3(prev_co, key->co);
		}
	}
	point->flag |= PEP_EDIT_RECALC;
}

static void scale_point_to_length(PTCacheEditPoint *point, float length)
{
	const float point_length = calculate_point_length(point);
	if (point_length != 0.0f) {
		const float factor = length / point_length;
		scale_point_factor(point, factor);
	}
}

static void scale_points_to_length(PTCacheEdit *edit, float length)
{
	POINT_P;
	LOOP_SELECTED_POINTS {
		scale_point_to_length(point, length);
	}
	recalc_lengths(edit);
}

static int unify_length_exec(bContext *C, wmOperator *UNUSED(op))
{
	Object *ob = CTX_data_active_object(C);
	Scene *scene = CTX_data_scene(C);
	PTCacheEdit *edit = PE_get_current(scene, ob);
	float average_length = calculate_average_length(edit);
	if (average_length == 0.0f) {
		return OPERATOR_CANCELLED;
	}
	scale_points_to_length(edit, average_length);

	PE_update_object(scene, ob, 1);
	if (edit->psys) {
		WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
	}
	else {
		DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
		WM_event_add_notifier(C, NC_OBJECT|ND_MODIFIER, ob);
	}

	return OPERATOR_FINISHED;
}

void PARTICLE_OT_unify_length(struct wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Unify Length";
	ot->idname = "PARTICLE_OT_unify_length";
	ot->description = "Make selected hair the same length";

	/* api callbacks */
	ot->exec = unify_length_exec;
	ot->poll = PE_poll_view3d;

	/* flags */
	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
}

