Simple Image Loading LibrarY  0.1.0
SILLYJPGImageLoader.cpp
1 /***********************************************************************
2  filename: SILLYJPGImageLoader.cpp
3  created: 11 Jun 2006
4  author: Olivier Delannoy
5 
6  purpose: Definition of JPGImageLoader methods
7 *************************************************************************/
8 /***************************************************************************
9  * Copyright (C) 2004 - 2006 Paul D Turner & The CEGUI Development Team
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining
12  * a copy of this software and associated documentation files (the
13  * "Software"), to deal in the Software without restriction, including
14  * without limitation the rights to use, copy, modify, merge, publish,
15  * distribute, sublicense, and/or sell copies of the Software, and to
16  * permit persons to whom the Software is furnished to do so, subject to
17  * the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be
20  * included in all copies or substantial portions of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
25  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  ***************************************************************************/
30 #ifdef HAVE_CONFIG_H
31 #include <config.h>
32 #endif
33 
34 #include "loaders/SILLYJPGImageLoader.h"
35 
36 #ifndef SILLY_OPT_INLINE
37 #define inline
38 #include "loaders/SILLYJPGImageLoader.icpp"
39 #undef inline
40 #endif
41 #include "loaders/SILLYJPGImageContext.h"
42 
43 // Start section of namespace SILLY
44 namespace SILLY
45 {
46 JPGImageLoader::JPGImageLoader()
47  : ImageLoader("JPG Image Loader based on jpeg-6b")
48 {
49 }
50 
51 JPGImageLoader::~JPGImageLoader()
52 {
53 }
54 
55 
57 {
59  jpg->d_source = data;
60 
61  if (! jpg)
62  return 0;
63  if (setjmp(jpg->setjmp_buffer))
64  {
65  delete jpg;
66  return 0;
67  }
68  jpeg_read_header(&(jpg->cinfo), TRUE);
69  if (! jpeg_start_decompress(&(jpg->cinfo)))
70  {
71  delete jpg;
72  return 0;
73  }
74 
75 
76  if (jpg->cinfo.output_components != 1 && jpg->cinfo.output_components != 3)
77  {
78  printf("JPG unsupported bpp: %d\n", jpg->cinfo.output_components );
79  jpeg_finish_decompress(& jpg->cinfo);
80  delete jpg;
81  return 0;
82  }
83  formatSource = PF_RGB; // It's not true but we handle both the same way
84  //printf("Image info: size: %dx%d - bpp: %d\n", jpg->cinfo.output_width, jpg->cinfo.output_height, jpg->cinfo.output_components);
85 
86  jpg->setImageSize();
87  return jpg;
88 }
89 
91  DataSource* data,
92  ImageContext* context)
93 {
94  JPGImageContext* jpg = static_cast<JPGImageContext*>(context);
95 
96  // Allocate a buffer
97  int row_stride = jpg->getWidth() * jpg->cinfo.output_components;
98  JSAMPARRAY buffer = (* jpg->cinfo.mem->alloc_sarray)(
99  (j_common_ptr)(& jpg->cinfo),
100  JPOOL_IMAGE,
101  row_stride,
102  1);
103  bool finished = true;
104  size_t height = jpg->getHeight();
105  size_t width = jpg->getWidth();
106 
107 
108  while(jpg->cinfo.output_scanline < height)
109  {
110  int num_rows = jpeg_read_scanlines(& jpg->cinfo, buffer, 1);
111  if (num_rows != 1)
112  {
113  jpeg_finish_decompress(& jpg->cinfo);
114  return false;
115  }
116  byte red;
117  byte green;
118  byte blue;
119  const byte alpha = 0xff;
120  byte* in = (byte*)(*buffer);
121  // Grayscale image
122  if (jpg->cinfo.output_components == 1)
123  {
124  for(size_t i = 0 ; i < width * num_rows ; ++i)
125  {
126  red = *in;
127  green = *in;
128  blue = *in;
129  jpg->setNextPixel(red, green, blue, alpha);
130  in += 1;
131  }
132  }
133  // RGB image
134  else
135  {
136  for(size_t i = 0 ; i < width * num_rows ; ++i)
137  {
138  red = *(in++);
139  green = *(in++);
140  blue = *(in++);
141  jpg->setNextPixel(red, green, blue, alpha);
142  }
143  }
144  }
145  jpeg_finish_decompress(& jpg->cinfo);
146 
147  if (origin == PO_BOTTOM_LEFT)
148  return jpg->flipVertically();
149  return true;
150 }
151 
152 
153 
154 
155 
156 
157 } // End section of namespace SILLY
PixelFormat
List all pixel format supported.
Definition: SILLYBase.h:59
bool flipVertically()
Flip pixel ordering.
void setNextPixel(byte red, byte green, byte bleu, byte alpha)
Set the next pixel of the image.
bool loadImageData(PixelOrigin origin, DataSource *data, ImageContext *context)
Parse the pixels data of the image and fill the header struct.
unsigned char byte
Typename for a byte.
Definition: SILLYBase.h:80
PixelOrigin
List all pixel origin supported.
Definition: SILLYBase.h:70
Store the data needed by an ImageLoader object during the parsing of an image.
Simple Image Loading LibrarY namespace.
Image Context for JPG image loader.
This is an abstract class used to provide data to the loader.
ImageContext * loadHeader(PixelFormat &header, DataSource *data)
Parse the header of the image and fill the header struct.