1 files changed, 31 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/compositor/compositor_edge_filter.glsl b/source/blender/gpu/shaders/compositor/compositor_edge_filter.glsl
new file mode 100644
index 00000000000..67e27c22602
--- /dev/null
+++ b/source/blender/gpu/shaders/compositor/compositor_edge_filter.glsl
@@ -0,0 +1,31 @@
+#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl)
+
+void main()
+{
+  ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+
+  /* Compute the dot product between the 3x3 window around the pixel and the edge detection kernel
+   * in the X direction and Y direction. The Y direction kernel is computed by transposing the
+   * given X direction kernel. */
+  vec3 color_x = vec3(0);
+  vec3 color_y = vec3(0);
+  for (int j = 0; j < 3; j++) {
+    for (int i = 0; i < 3; i++) {
+      vec3 color = texture_load(input_tx, texel + ivec2(i - 1, j - 1)).rgb;
+      color_x += color * kernel[j][i];
+      color_y += color * kernel[i][j];
+    }
+  }
+
+  /* Compute the channel-wise magnitude of the 2D vector composed from the X and Y edge detection
+   * filter results. */
+  vec3 magnitude = sqrt(color_x * color_x + color_y * color_y);
+
+  /* Mix the channel-wise magnitude with the original color at the center of the kernel using the
+   * input factor. */
+  vec4 color = texture_load(input_tx, texel);
+  magnitude = mix(color.rgb, magnitude, texture_load(factor_tx, texel).x);
+
+  /* Store the channel-wise magnitude with the original alpha of the input. */
+  imageStore(output_img, texel, vec4(magnitude, color.a));
+}