# HG changeset patch
# User František Kučera <franta-hg@frantovo.cz>
# Date 1701217625 -3600
# Node ID 9aba96f0b001380173e029f04e2d3c1b3d567961
# Parent  48dc4ae894b04d4e0f8ccc220c2d2489c9ac17a1
fragment shader: add grayscale() function

diff -r 48dc4ae894b0 -r 9aba96f0b001 shaders/first.frag
--- a/shaders/first.frag	Wed Nov 29 01:21:17 2023 +0100
+++ b/shaders/first.frag	Wed Nov 29 01:27:05 2023 +0100
@@ -4,7 +4,14 @@
 in       vec2       vTextureXY;
 out      vec3       fColor;
 
+vec3 grayscale(vec3 original) {
+	const vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
+	float luminance = dot(original, luminanceWeighting);
+	return vec3(luminance);
+}
+
 void main(){
 	fColor = texture(uTexture, vTextureXY).rgb;
+	// fColor = grayscale(fColor);
 	// fColor *= vec3(0.8, 1., 0.2);
 }