1uniform half4 colorGreen, colorRed; 2 3half4 main(float2 coords) { 4 float4 value = colorGreen.gggg * 2.5; 5 float4 whole, fraction; 6 bool4 ok; 7 8 // 2.5 equals 2 + 0.5. 9 fraction.x = modf(value.x, whole.x); 10 ok.x = whole.x == 2 && fraction.x == 0.5; 11 fraction.xy = modf(value.xy, whole.xy); 12 ok.y = whole.y == 2 && fraction.y == 0.5; 13 fraction.xyz = modf(value.xyz, whole.xyz); 14 ok.z = whole.z == 2 && fraction.z == 0.5; 15 fraction.xyzw = modf(value.xyzw, whole.xyzw); 16 ok.w = whole.w == 2 && fraction.w == 0.5; 17 18 return all(ok) ? colorGreen : colorRed; 19} 20