git.sesse.net Git - movit/blob - resample_effect.frag

   1 // DIRECTION_VERTICAL will be #defined to 1 if we are scaling vertically,
   2 // and 0 otherwise.
   3
   4 uniform sampler2D PREFIX(sample_tex);
   5 uniform int PREFIX(num_samples);
   6 uniform float PREFIX(sample_x_scale);
   7 uniform float PREFIX(sample_x_offset);
   8
   9 // Sample a single weight. First fetch information about where to sample
  10 // and the weight from sample_tex, and then read the pixel itself.
  11 vec4 PREFIX(do_sample)(vec2 tc, int i)
  12 {
  13         vec2 sample_tc;
  14         sample_tc.x = float(i) * PREFIX(sample_x_scale) + PREFIX(sample_x_offset);
  15 #if DIRECTION_VERTICAL
  16         sample_tc.y = tc.y;
  17 #else
  18         sample_tc.y = tc.x;
  19 #endif
  20         vec2 sample = texture2D(PREFIX(sample_tex), sample_tc).rg;
  21
  22 #if DIRECTION_VERTICAL
  23         tc.y = sample.g;
  24 #else
  25         tc.x = sample.g;
  26 #endif
  27         return vec4(sample.r) * INPUT(tc);
  28 }
  29
  30 vec4 FUNCNAME(vec2 tc) {
  31         vec4 sum = PREFIX(do_sample)(tc, 0);
  32         for (int i = 1; i < PREFIX(num_samples); ++i) {
  33                 sum += PREFIX(do_sample)(tc, i);
  34         }
  35         return sum;
  36 }
  37
  38 #undef DIRECTION_VERTICAL