1 // DIRECTION_VERTICAL will be #defined to 1 if we are scaling vertically,
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);
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)
14 sample_tc.x = float(i) * PREFIX(sample_x_scale) + PREFIX(sample_x_offset);
15 #if DIRECTION_VERTICAL
20 vec2 sample = texture2D(PREFIX(sample_tex), sample_tc).rg;
22 #if DIRECTION_VERTICAL
27 return vec4(sample.r) * INPUT(tc);
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);
38 #undef DIRECTION_VERTICAL