1 uniform float PREFIX(output_coord_to_slice_num);
2 uniform float PREFIX(slice_num_to_input_coord);
3 uniform float PREFIX(slice_offset_to_input_coord);
4 uniform float PREFIX(offset);
6 vec4 FUNCNAME(vec2 tc) {
7 // DIRECTION_VERTICAL will be #defined to 1 if we are expanding vertically,
10 float sliced_coord = 1.0 - tc.y;
12 float sliced_coord = tc.x;
15 // Find out which slice we are in, and a 0..1 coordinate for the offset within that slice.
16 float slice_num = floor(sliced_coord * PREFIX(output_coord_to_slice_num));
17 float slice_offset = fract(sliced_coord * PREFIX(output_coord_to_slice_num));
19 // Find out where this slice begins in the input data, and then offset from that.
20 float input_coord = slice_num * PREFIX(slice_num_to_input_coord) + slice_offset * PREFIX(slice_offset_to_input_coord) + PREFIX(offset);
22 #if DIRECTION_VERTICAL
23 return INPUT(vec2(tc.x, 1.0 - input_coord));
25 return INPUT(vec2(input_coord, tc.y));