1 files changed, 68 insertions, 0 deletions
diff --git a/source/blender/draw/engines/gpencil/shaders/fx/gpencil_fx_glow_prepare_frag.glsl b/source/blender/draw/engines/gpencil/shaders/fx/gpencil_fx_glow_prepare_frag.glsl
new file mode 100644
index 00000000000..237cdf15627
--- /dev/null
+++ b/source/blender/draw/engines/gpencil/shaders/fx/gpencil_fx_glow_prepare_frag.glsl
@@ -0,0 +1,68 @@
+uniform mat4 ProjectionMatrix;
+uniform mat4 ViewMatrix;
+
+/* ******************************************************************* */
+/* create glow mask                                                    */
+/* ******************************************************************* */
+uniform sampler2D strokeColor;
+uniform sampler2D strokeDepth;
+
+uniform vec3 glow_color;
+uniform vec3 select_color;
+uniform float threshold;
+uniform int mode;
+
+out vec4 FragColor;
+
+#define MODE_LUMINANCE   0
+#define MODE_COLOR       1
+
+/* calc luminance */
+float luma( vec3 color ) {
+	/* the color is linear, so do not apply tonemapping */
+	return (color.r + color.g + color.b) / 3.0;
+}
+
+bool check_color(vec3 color_a, vec3 color_b)
+{
+ /* need round the number to avoid precision errors */
+	if ((floor(color_a.r * 100) == floor(color_b.r * 100)) &&
+		(floor(color_a.g * 100) == floor(color_b.g * 100)) &&
+		(floor(color_a.b * 100) == floor(color_b.b * 100))) 
+		{
+		return true;
+		}
+
+ return false;
+}
+
+void main()
+{
+	vec2 uv = vec2(gl_FragCoord.xy);
+
+	float stroke_depth = texelFetch(strokeDepth, ivec2(uv.xy), 0).r;
+	vec4 src_pixel= texelFetch(strokeColor, ivec2(uv.xy), 0);
+	vec4 outcolor;
+
+	/* is transparent */
+	if (src_pixel.a == 0.0f) {
+		discard;
+	}
+
+	if (mode == MODE_LUMINANCE) {
+		if (luma(src_pixel.rgb) < threshold) {
+			discard;
+		}
+	}
+	else if (mode == MODE_COLOR) {
+		if (!check_color(src_pixel.rgb, select_color.rgb)) {
+			discard;
+		}
+	}
+	else {
+		discard;
+	}
+	
+	gl_FragDepth = stroke_depth;
+	FragColor = vec4(glow_color.rgb, 1.0);
+}