1 files changed, 27 insertions, 0 deletions
diff --git a/source/blender/compositor/realtime_compositor/shaders/library/gpu_shader_compositor_color_matte.glsl b/source/blender/compositor/realtime_compositor/shaders/library/gpu_shader_compositor_color_matte.glsl
new file mode 100644
index 00000000000..038471bc1bc
--- /dev/null
+++ b/source/blender/compositor/realtime_compositor/shaders/library/gpu_shader_compositor_color_matte.glsl
@@ -0,0 +1,27 @@
+#pragma BLENDER_REQUIRE(gpu_shader_common_color_utils.glsl)
+
+void node_composite_color_matte(vec4 color,
+                                vec4 key,
+                                float hue_epsilon,
+                                float saturation_epsilon,
+                                float value_epsilon,
+                                out vec4 result,
+                                out float matte)
+
+{
+  vec4 color_hsva;
+  rgb_to_hsv(color, color_hsva);
+  vec4 key_hsva;
+  rgb_to_hsv(key, key_hsva);
+
+  bool is_within_saturation = distance(color_hsva.y, key_hsva.y) < saturation_epsilon;
+  bool is_within_value = distance(color_hsva.z, key_hsva.z) < value_epsilon;
+  bool is_within_hue = distance(color_hsva.x, key_hsva.x) < hue_epsilon;
+  /* Hue wraps around, so check the distance around the boundary. */
+  float min_hue = min(color_hsva.x, key_hsva.x);
+  float max_hue = max(color_hsva.x, key_hsva.x);
+  is_within_hue = is_within_hue || ((min_hue + (1.0 - max_hue)) < hue_epsilon);
+
+  matte = (is_within_hue && is_within_saturation && is_within_value) ? 0.0 : color.a;
+  result = color * matte;
+}