!!ARBfp1.0
TEMP output;
TEMP input;
TEMP bright;
TEMP dark;
TEX input, fragment.texcoord[0], texture[0], RECT;
# Subtract color by 0.51 => everything with more then 0.51 will have at least 0 ;
SUB output.rgb, input, 0.51;
# Create a dark color..;
SUB dark.rgb, input, 0.3;
# ..and a bright color ;
ADD bright.rgb, input, 0.3;
# All colors which are < 0 (original color - 0.51 < 0) get a dark color and everything else a bright color ;
CMP output.rgb, output, dark, bright;
MOV result.color, output;
END