Move everything into a separate futatabi/ subdir, for the upcoming merge with Nageru.

[nageru] / futatabi / splat.vert

diff --git a/futatabi/splat.vert b/futatabi/splat.vert
new file mode 100644 (file)
index 0000000..0846231
--- /dev/null
+++ b/futatabi/splat.vert
@@ -0,0 +1,51 @@
+#version 450 core
+
+layout(location=0) in vec2 position;
+out vec2 image_pos;
+flat out vec2 flow, I_0_check_offset, I_1_check_offset;
+
+uniform vec2 splat_size;  // In 0..1 coordinates.
+uniform vec2 inv_flow_size;
+uniform float alpha;
+uniform sampler2DArray flow_tex;  // 0 = forward flow, 1 = backward flow.
+
+void main()
+{
+       int instance = gl_InstanceID;
+       int num_pixels_per_layer = textureSize(flow_tex, 0).x * textureSize(flow_tex, 0).y;
+       int src_layer;
+       if (instance >= num_pixels_per_layer) {
+               instance -= num_pixels_per_layer;
+               src_layer = 1;
+       } else {
+               src_layer = 0;
+       }
+       int x = instance % textureSize(flow_tex, 0).x;
+       int y = instance / textureSize(flow_tex, 0).x;
+
+       // Find out where to splat this to.
+       vec2 full_flow = texelFetch(flow_tex, ivec3(x, y, src_layer), 0).xy;
+       float splat_alpha;
+       if (src_layer == 1) {  // Reverse flow.
+               full_flow = -full_flow;
+               splat_alpha = 1.0f - alpha;
+       } else {
+               splat_alpha = alpha;
+       }
+       full_flow *= inv_flow_size;
+       
+       vec2 patch_center = (ivec2(x, y) + 0.5) * inv_flow_size + full_flow * splat_alpha;
+       image_pos = patch_center + splat_size * (position - 0.5);
+
+       flow = full_flow;
+       I_0_check_offset = full_flow * -alpha;
+       I_1_check_offset = full_flow * (1.0f - alpha);
+
+       // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is:
+       //
+       //   2.000  0.000  0.000 -1.000
+       //   0.000  2.000  0.000 -1.000
+       //   0.000  0.000 -2.000 -1.000
+       //   0.000  0.000  0.000  1.000
+       gl_Position = vec4(2.0 * image_pos.x - 1.0, 2.0 * image_pos.y - 1.0, -1.0, 1.0);
+}