Prepare given State, to be able to render shapes with it. Between preparing and unpreparing, nodes passed here are "frozen": do not change, do not free them.
Release every OpenGL and VRML resource. That is release any knowledge connecting us to the current OpenGL context and any knowledge about your prepared VRML nodes, states etc.
Calling UnprepareAll is valid (and ignored) call if everything is already released.
Destructor callls UnprepareAll automatically. So be sure to either call UnprepareAll or destroy this renderer when your OpenGL context is still active.
Load GLSL shader for the ScreenEffect node. Makes sure that Node.ShaderLoaded is true. When changing Node.ShaderLoaded false to true tries to initialize the shader, setting Node.Shader if some GLSL program was successfully loaded.
The GLSL program (TGLSLProgram) will be stored here, and will be automatically freed during UnprepareAll call.
Rendering attributes. You can change them only when renderer is not tied to the current OpenGL context, so only after construction or after UnprepareAll call (before any Prepare or Render* calls).