Psychtoolbox>Screen.{mex*} subfunction

[textureHandle rect] = Screen(‘SetOpenGLTextureFromMemPointer’, windowPtr, textureHandle, imagePtr, width, height, depth [, upsidedown][, target][, glinternalformat][, gltype][, extdataformat][, specialFlags]);

DANGEROUS! C-PROGRAMMING EXPERTS ONLY! OTHERS STAY AWAY! Convert raw image data,
provided as a pointer to a system memory buffer, into a Psychtoolbox texture.
CAUTION: Providing wrong arguments to this subfunction will definitely crash
Psychtoolbox and Matlab! “windowPtr” is the handle of the onscreen window to
which the texture should be attached. ‘textureHandle’ is either the Psychtoolbox
handle for an existing PTB texture that should be updated with the new raw pixel
data, or the special value zero or [] if a completely new PTB texture should be
created from the raw pixel data. ‘imagePtr’ is a C programming language (void*)
memory pointer that points to the start of a memory buffer with the raw image
data. The pointer needs to be encoded in a special way. Read the source code of
Memorybuffer2Texture.c and Memorybuffer2TextureDemo.m for minimal examples on
how to do this properly. Memorybuffer2Texture.cc demonstrates the same for
GNU/Octave. The optional parameter ‘target’ is the type of texture object to
create, e.g., GL_TEXTURE_2D. Normally you’ll just leave it out, so PTB can
choose the optimal texture format for a system. ‘width’ and ‘height’ are the
width and height of the image. ‘depth’ is the depth of the image: 1 = Input is a
greyscale image with 1 Byte per pixel. 3 = Input is a RGB truecolor image with 3
Bytes per pixel. 2 and 4 are like 1 and 3, but with one byte for an alpha
(transparency) channel added. The optional flag ‘upsidedown’ can be set to one
(default is zero) to create textures upside-down - inverted in vertical
direction. ‘glinternalformat’, ‘gltype’ and ‘extdataformat’ are all optional. If
you provide one of them, you’ll need to provide all of them. In that case, PTB
will create an OpenGL texture with exactly the specified internal format,
assuming input data that is of type ‘gltype’ and in numeric data format
‘extdataformat’. You are completely responsible for passing properly formatted
data. This is mostly useful for injecting high dynamic range texture images and
other exotic texture formats.
‘specialFlags’ Special optional texture flags, see help for
Screen(‘MakeTexture’).
The function returns the textureHandle of the PTB texture and its defining
rectangle. This routine allows external C-Code (Mex- or Oct-Files) to inject raw
image data as a texture into PTB.

###See also: SetOpenGLTexture MakeTexture