$input v_color0, v_texcoord0 #include "../../common/common.sh" SAMPLERCUBE(s_texColor, 0); void main() { vec4 color = textureCube(s_texColor, v_texcoord0.xyz); int index = int(v_texcoord0.w*4.0 + 0.5); float alpha = index < 1 ? color.z : index < 2 ? color.y : index < 3 ? color.x : color.w; gl_FragColor = vec4(v_color0.xyz, v_color0.a * alpha); }