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(num_loops);
   7 uniform float PREFIX(sample_x_scale);
   8 uniform float PREFIX(sample_x_offset);
   9 uniform float PREFIX(slice_height);
  10
  11 // Sample a single weight. First fetch information about where to sample
  12 // and the weight from sample_tex, and then read the pixel itself.
  13 vec4 PREFIX(do_sample)(vec2 tc, int i)
  14 {
  15         vec2 sample_tc;
  16         sample_tc.x = float(i) * PREFIX(sample_x_scale) + PREFIX(sample_x_offset);
  17 #if DIRECTION_VERTICAL
  18         sample_tc.y = tc.y * PREFIX(num_loops);
  19 #else
  20         sample_tc.y = tc.x * PREFIX(num_loops);
  21 #endif
  22         vec2 sample = texture2D(PREFIX(sample_tex), sample_tc).rg;
  23
  24 #if DIRECTION_VERTICAL
  25         tc.y = sample.g + floor(sample_tc.y) * PREFIX(slice_height);
  26 #else
  27         tc.x = sample.g + floor(sample_tc.y) * PREFIX(slice_height);
  28 #endif
  29         return vec4(sample.r) * INPUT(tc);
  30 }
  31
  32 vec4 FUNCNAME(vec2 tc) {
  33         vec4 sum = PREFIX(do_sample)(tc, 0);
  34         for (int i = 1; i < PREFIX(num_samples); ++i) {
  35                 sum += PREFIX(do_sample)(tc, i);
  36         }
  37         return sum;
  38 }
  39
  40 #undef DIRECTION_VERTICAL