Re: Cg et la programmation du GPU : Un exemple

Par exemple, un shader pour blurrer une texture (ati 9600 ou geforce fx) a charger avec (GL_FRAGMENT_PROGRAM_ARB) :

# la version du shader
!!ARBfp1.0

PARAM param = { 2.0, -1.0, 0.0, 0.0 };
PARAM offset = program.env[0];
TEMP src, coord0, coord1, old, new, temp;
# texture source
TEX src, fragment.texcoord[0], texture[0], 2D;
# calcule le decalage
ADD coord0, fragment.texcoord[0], offset;
MUL coord0, coord0, 10;
TEX coord0, coord0, texture[2], 2D;
MAD coord0, coord0, param.x, param.y;
TEX coord1, fragment.texcoord[0], texture[1], 2D;
MAD coord1, coord1, param.x, param.y;
MAD coord0, coord0, 0.02, fragment.texcoord[0];
MAD coord1, coord1, 0.02, coord0;
# points voisins
TEX new, coord1, texture[3], 2D;
# point courant
TEX old, fragment.texcoord[0], texture[3], 2D;
# Blur !!!
MAD old, new, 1, old;
MUL new, old, 0.492;
# replace la source
SGE temp, src, 0.3;
MUL src, src, temp;
SUB temp, 1, temp;
MUL new, new, temp;
ADD result.color, new, src;
END