psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1 / usr / share / psychtoolbox-3 / PsychOpenGL / PsychGLSLShaders / moglFDFSilhouetteRenderShader.frag.txt

/* FDF shader for 1st object render pass: Encodes figure-background
 * flag into B channel and surface coordinate into RG channels.
 *
 * (c) 2008 by Mario Kleiner, licensed under MIT license.
 */

void main(void)
{
    /* Encode object surface texture coordinates in RG: */
    gl_FragColor.rg = gl_TexCoord[0].st;

    /* Encode a 1 in B channel -- Mark it as foreground pixel: */
    gl_FragColor.b  = 1.0;

    /* Encode interpolated depths in A channel, for no special reason: */
    gl_FragColor.a  = gl_FragCoord.z;
}