be ideal.
*/
-const uint patch_size = 12;
-const uint num_iterations = 8;
-
-in vec2 flow_tc;
+in vec3 flow_tc;
in vec2 patch_center;
+flat in int ref_layer, search_layer;
out vec3 out_flow;
-uniform sampler2D flow_tex, grad0_tex, image0_tex, image1_tex;
+uniform sampler2DArray flow_tex, image_tex;
+uniform usampler2DArray grad_tex; // Also contains the corresponding reference image.
uniform vec2 inv_image_size, inv_prev_level_size;
+uniform uint patch_size;
+uniform uint num_iterations;
+
+vec3 unpack_gradients(uint v)
+{
+ uint vi = v & 0xffu;
+ uint xi = (v >> 8) & 0xfffu;
+ uint yi = v >> 20;
+ vec3 r = vec3(xi * (1.0f / 4095.0f) - 0.5f, yi * (1.0f / 4095.0f) - 0.5f, vi * (1.0f / 255.0f));
+ return r;
+}
+
+// Note: The third variable is the actual pixel value.
+vec3 get_gradients(vec3 tc)
+{
+ vec3 grad = unpack_gradients(texture(grad_tex, tc).x);
+
+ // Zero gradients outside the image. (We'd do this with a sampler,
+ // but we want the repeat behavior for the actual texels, in the
+ // z channel.)
+ if (any(lessThan(tc.xy, vec2(0.0f))) || any(greaterThan(tc.xy, vec2(1.0f)))) {
+ grad.xy = vec2(0.0f);
+ }
+
+ return grad;
+}
void main()
{
- vec2 image_size = textureSize(image0_tex, 0);
+ vec2 image_size = textureSize(grad_tex, 0).xy;
// Lock the patch center to an integer, so that we never get
// any bilinear artifacts for the gradient. (NOTE: This assumes an
for (uint y = 0; y < patch_size; ++y) {
for (uint x = 0; x < patch_size; ++x) {
vec2 tc = base + uvec2(x, y) * inv_image_size;
- vec2 grad = texture(grad0_tex, tc).xy;
+ vec3 grad = get_gradients(vec3(tc, ref_layer));
H[0][0] += grad.x * grad.x;
H[1][1] += grad.y * grad.y;
H[0][1] += grad.x * grad.y;
- template_sum += texture(image0_tex, tc).x;
- grad_sum += grad;
+ template_sum += grad.z; // The actual template pixel value.
+ grad_sum += grad.xy;
}
}
H[1][0] = H[0][1];
for (uint y = 0; y < patch_size; ++y) {
for (uint x = 0; x < patch_size; ++x) {
vec2 tc = base + uvec2(x, y) * inv_image_size;
- vec2 grad = texture(grad0_tex, tc).xy;
- float t = texture(image0_tex, tc).x;
- float warped = texture(image1_tex, tc + u_norm).x;
- du += grad * (warped - t);
+ vec3 grad = get_gradients(vec3(tc, ref_layer));
+ float t = grad.z;
+ float warped = texture(image_tex, vec3(tc + u_norm, search_layer)).x;
+ du += grad.xy * (warped - t);
warped_sum += warped;
}
}