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

[nageru] / futatabi / densify.frag

diff --git a/futatabi/densify.frag b/futatabi/densify.frag
new file mode 100644 (file)
index 0000000..3bca126
--- /dev/null
+++ b/futatabi/densify.frag
@@ -0,0 +1,24 @@
+#version 450 core
+
+in vec2 image_pos;
+flat in int image0_layer, image1_layer;
+flat in vec2 flow_du;
+flat in float mean_diff;
+out vec3 flow_contribution;
+
+uniform sampler2DArray image_tex;
+
+void main()
+{
+       // Equation (3) from the paper. We're using additive blending, so the
+       // sum will happen automatically for us, and normalization happens on
+       // next read.
+       //
+       // Note that equation (2) says 1 for the minimum error, but the code says 2.0.
+       // And it says L2 norm, but really, the code does absolute value even for
+       // L2 error norm (it uses a square root formula for L1 norm).
+       float diff = texture(image_tex, vec3(image_pos, image0_layer)).x - texture(image_tex, vec3(image_pos + flow_du, image1_layer)).x;
+       diff -= mean_diff;
+       float weight = 1.0 / max(abs(diff), 2.0 / 255.0);
+       flow_contribution = vec3(flow_du.x * weight, flow_du.y * weight, weight);
+}