1#version 120
2
3varying vec4 var_color;
4
5#define PI 3.141592653589793
6
7void main() {
8	// Empirically found shading function that got consensus.
9	float alpha = pow(cos(var_color.a * PI / 2), 1.5);
10	gl_FragColor = vec4(var_color.r, var_color.g, var_color.b, alpha);
11}
12