1 files changed, 31 insertions, 0 deletions
diff --git a/source/blender/draw/engines/gpencil/shaders/gpencil_layer_blend_frag.glsl b/source/blender/draw/engines/gpencil/shaders/gpencil_layer_blend_frag.glsl
new file mode 100644
index 00000000000..6fbc7f47dac
--- /dev/null
+++ b/source/blender/draw/engines/gpencil/shaders/gpencil_layer_blend_frag.glsl
@@ -0,0 +1,31 @@
+
+uniform sampler2D colorBuf;
+uniform sampler2D revealBuf;
+uniform sampler2D maskBuf;
+uniform int blendMode;
+uniform float blendOpacity;
+
+in vec4 uvcoordsvar;
+
+/* Reminder: This is considered SRC color in blend equations.
+ * Same operation on all buffers. */
+layout(location = 0) out vec4 fragColor;
+layout(location = 1) out vec4 fragRevealage;
+
+void main()
+{
+  vec4 color;
+
+  /* Remember, this is associated alpha (aka. premult). */
+  color.rgb = textureLod(colorBuf, uvcoordsvar.xy, 0).rgb;
+  /* Stroke only render mono-chromatic revealage. We convert to alpha. */
+  color.a = 1.0 - textureLod(revealBuf, uvcoordsvar.xy, 0).r;
+
+  float mask = textureLod(maskBuf, uvcoordsvar.xy, 0).r;
+  mask *= blendOpacity;
+
+  fragColor = vec4(1.0, 0.0, 1.0, 1.0);
+  fragRevealage = vec4(1.0, 0.0, 1.0, 1.0);
+
+  blend_mode_output(blendMode, color, mask, fragColor, fragRevealage);
+}