Exactly! I need it for the same purpose as you!
I experimented a bit, and here it is:
Melatonin, you can come!!!ARBfp1.0
TEMP tex, temp;
TEX tex, fragment.texcoord[0], texture[0], RECT;
DP3 temp.r, tex, {0.9, 0, 0, 0};
DP3 temp.g, tex, {0, 0.9, 0, 0};
DP3 temp.b, tex, {0, 0, 0, 0};
MOV temp.a, tex.a;
MOV result.color, temp;
END
Bookmarks