Doodle3D-Core/shaders/matcap_frag.glsl

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2017-11-23 17:29:56 +01:00
uniform float opacity;
uniform sampler2D tMatcap;
uniform vec3 color;
varying vec2 vNormal;
// color blending from https://www.w3.org/TR/compositing-1/#blendingcolor
float lum(vec3 c) {
return c.r * .3 + c.g * .59 + c.b * .11;
}
vec3 clipColor(vec3 c) {
float l = lum(c);
float n = min(min(c.r, c.g), c.b);
float x = max(max(c.r, c.g), c.b);
if (n < 0.) c = l + (((c - l) * l) / (l - n));
if (x > 1.) c = l + (((c - l) * (1. - l)) / (x - l));
return c;
}
vec3 setLum(vec3 c, float l) {
float d = l - lum(c);
return clipColor(c + d);
}
void main() {
vec4 matcap = texture2D(tMatcap, vNormal);
vec3 coloredMatcap = setLum(color, lum(matcap.rgb));
gl_FragColor = vec4(coloredMatcap, opacity);
}