SuperTuxKart 1.5 upstream source (from official release tarball)

data/shaders/glow.frag

@@ -0,0 +1,19 @@
+uniform sampler2D tex;
+
+in vec2 uv;
+out vec4 FragColor;
+
+void main()
+{
+	vec2 coords = uv;
+
+	vec4 col = texture(tex, coords);
+	float alpha = col.a;
+
+	if (alpha < 0.04 || length(col.xyz) < 0.2) discard;
+    
+	col *= vec4(vec3(4.0), 1.5);
+    col.a *= 0.6;
+    
+	FragColor = col;
+}