Screen(‘SetOpenGLTexture’)

Psychtoolbox>Screen.{mex*} subfunction

Provides information about an external OpenGL texture to make it acessible for
PTB as PTB texture.”windowPtr” is the handle of the onscreen window to which
texture should be attached. ‘textureHandle’ is either the Psychtoolbox handle
for an existing PTB texture, or the special value zero or [] if a completely new
PTB texture should be created for this OpenGL texture. glTexid is the OpenGL
texture id of a valid OpenGL texture object. ‘target’ is the type of texture
(e.g., GL_TEXTURE_2D) Optionally you can pass in the intended width and height
as well as pixeldepth of the texture if they should be different from the values
that PTB can autodetect from the given texture object.
‘textureShader’ - optional: If you provide the handle of an OpenGL GLSL shader
program, then this shader program will be executed (bound) during drawing of
this texture via the Screen(‘DrawTexture’,…); command – The normal texture
drawing operation is replaced by your customized algorithm. This is useful for
two purposes: a) Very basic on-the-fly image processing on the texture. b)
Procedural shading: Your texture matrix doesn’t encode an image, but only
per-pixel parameters is input for some formula to compute the real image during
drawing. E.g., instead of defining a gabor patch as image or other standard
stimulus, one could define it as a mathematical formula to be evaluated at
draw-time. The Screen(‘SetOpenGLTexture’) command allows you to create purely
virtual textures, that only consist of such a shader and some virtual size, but
don’t have any real data matrix associated with it – all content is generated
on the fly. Create such a texture by providing a textureShader that will
algorithmically generate the texture content, and the virtual size of the
texture in glWidth, glHeight and glDepth, but set the glTexid texture handle to
zero.
‘specialFlags’ Special optional texture flags, see help for
Screen(‘MakeTexture’).
The function returns (optionally) the textureHandle of the PTB texture and its
defining rectangle. This routine allows external OpenGL code to inject textures
into PTB for use with it. For more info about OpenGL textures, read an OpenGL
book.

###See also: GetOpenGLTexture