1 files changed, 21 insertions, 0 deletions
diff --git a/src/effects/shaders_ng/desaturate.frag b/src/effects/shaders_ng/desaturate.frag
new file mode 100644
index 0000000..b54b3ac
--- /dev/null
+++ b/src/effects/shaders_ng/desaturate.frag
@@ -0,0 +1,21 @@
+#version 440
+
+layout(location = 0) in vec2 qt_TexCoord0;
+layout(location = 0) out vec4 fragColor;
+
+layout(std140, binding = 0) uniform buf {
+    // qt_Matrix and qt_Opacity must always be both present
+    // if the built-in vertex shader is used.
+    mat4 qt_Matrix;
+    float qt_Opacity;
+    float desaturation;
+};
+
+layout(binding = 1) uniform sampler2D source;
+
+void main(void)
+{
+    vec4 textureColor = texture(source, qt_TexCoord0.st);
+    float grayColor = (textureColor.r + textureColor.g + textureColor.b) / 3.0;
+    fragColor = mix(textureColor, vec4(vec3(grayColor), textureColor.a), desaturation) * qt_Opacity;
+}