+ return 1.0 - smoothstep(1.0, chroma_softness, d);
+ }
+
+ // http://stackoverflow.com/questions/15095909/from-rgb-to-hsv-in-opengl-glsl
+ vec3 rgb2hsv(vec3 c)
+ {
+ vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+ vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+ vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+ float d = q.x - min(q.w, q.y);
+ float e = 1.0e-10;
+ return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+ }
+
+ // From the same page
+ vec3 hsv2rgb(vec3 c)
+ {
+ vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+ vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+ return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+ }
+
+ float AngleDiff(float angle1, float angle2)
+ {
+ return 0.5 - abs(abs(angle1 - angle2) - 0.5);