// DIRECTION_VERTICAL will be #defined to 1 if we are scaling vertically, // and 0 otherwise. uniform sampler2D PREFIX(sample_tex); uniform int PREFIX(num_samples); uniform float PREFIX(num_loops); uniform float PREFIX(sample_x_scale); uniform float PREFIX(sample_x_offset); uniform float PREFIX(slice_height); // Sample a single weight. First fetch information about where to sample // and the weight from sample_tex, and then read the pixel itself. vec4 PREFIX(do_sample)(vec2 tc, int i) { vec2 sample_tc; sample_tc.x = float(i) * PREFIX(sample_x_scale) + PREFIX(sample_x_offset); #if DIRECTION_VERTICAL sample_tc.y = tc.y * PREFIX(num_loops); #else sample_tc.y = tc.x * PREFIX(num_loops); #endif vec2 sample = texture2D(PREFIX(sample_tex), sample_tc).rg; #if DIRECTION_VERTICAL tc.y = sample.g + floor(sample_tc.y) * PREFIX(slice_height); #else tc.x = sample.g + floor(sample_tc.y) * PREFIX(slice_height); #endif return vec4(sample.r) * INPUT(tc); } vec4 FUNCNAME(vec2 tc) { vec4 sum = PREFIX(do_sample)(tc, 0); for (int i = 1; i < PREFIX(num_samples); ++i) { sum += PREFIX(do_sample)(tc, i); } return sum; } #undef DIRECTION_VERTICAL