Use textureSize() instead of sending in uniforms manually. Same result, less code...

[nageru] / motion_search.frag

diff --git a/motion_search.frag b/motion_search.frag
index d407c0d7ea2a2a29889f5a4b5075d7286c0b0528..05e901c12844cfa3dd38753435c4b8e649fd0144 100644 (file)
--- a/motion_search.frag
+++ b/motion_search.frag
@@ -36,20 +36,23 @@
  */
 
 const uint patch_size = 12;
-const uint num_iterations = 16;
+const uint num_iterations = 8;
 
 in vec2 flow_tc;
-in vec2 patch_bottom_left_texel;  // Center of bottom-left texel of patch.
+in vec2 patch_center;
 out vec3 out_flow;
 
 uniform sampler2D flow_tex, grad0_tex, image0_tex, image1_tex;
-uniform vec2 image_size, inv_image_size, inv_prev_level_size;
+uniform vec2 inv_image_size, inv_prev_level_size;
 
 void main()
 {
-       // Lock patch_bottom_left_texel to an integer, so that we never get
-       // any bilinear artifacts for the gradient.
-       vec2 base = (round(patch_bottom_left_texel * image_size - vec2(0.5, 0.5)) + vec2(0.5, 0.5))
+       vec2 image_size = textureSize(image0_tex, 0);
+
+       // Lock the patch center to an integer, so that we never get
+       // any bilinear artifacts for the gradient. (NOTE: This assumes an
+       // even patch size.) Then calculate the bottom-left texel of the patch.
+       vec2 base = (round(patch_center * image_size) - (0.5f * patch_size - 0.5f))
                * inv_image_size;
 
        // First, precompute the pseudo-Hessian for the template patch.
@@ -139,11 +142,12 @@ void main()
        // Also reject if the patch goes out-of-bounds (the paper does not mention this,
        // but the code does, and it seems to be critical to avoid really bad behavior
        // at the edges).
+       vec2 patch_center = (base * image_size - 0.5f) + patch_size * 0.5f + u;
        if (length(u - initial_u) > (patch_size * 0.5f) ||
-           u.x < -(patch_size * 0.5f) ||
-           image_size.x - u.x < -(patch_size * 0.5f) ||
-           u.y < -(patch_size * 0.5f) ||
-           image_size.y - u.y < -(patch_size * 0.5f)) {
+           patch_center.x < -(patch_size * 0.5f) ||
+           image_size.x - patch_center.x < -(patch_size * 0.5f) ||
+           patch_center.y < -(patch_size * 0.5f) ||
+           image_size.y - patch_center.y < -(patch_size * 0.5f)) {
                u = initial_u;
                mean_diff = first_mean_diff;
        }