opencl/hue-chroma.cl

   1 #define EPSILON     1e-4f
   2
   3 __kernel void gegl_hue_chroma (__global const float4 *in,
   4                                __global       float4 *out,
   5                                               float   hue,
   6                                               float   chroma,
   7                                               float   lightness)
   8 {
   9   int gid = get_global_id(0);
  10   float4 in_v  = in [gid];
  11   float4 out_v;
  12
  13   if (fabs (in_v.y) > EPSILON)
  14     {
  15       out_v.y = in_v.y + chroma;
  16       out_v.z = in_v.z + hue;
  17     }
  18   else
  19     {
  20       out_v.y = in_v.y;
  21       out_v.z = in_v.z;
  22     }
  23
  24   out_v.x = in_v.x + lightness;
  25   out_v.y = clamp (out_v.y, 0.f, 300.f);
  26   out_v.w = in_v.w;
  27   out[gid]  =  out_v;
  28 }