1 // A simple, circular vignette, with a cosĀ² falloff.
3 uniform float PREFIX(pihalf_div_radius);
4 uniform vec2 PREFIX(aspect_correction);
5 uniform vec2 PREFIX(flipped_center);
7 vec4 FUNCNAME(vec2 tc) {
10 const float pihalf = 0.5 * 3.14159265358979324;
12 vec2 normalized_pos = (tc - PREFIX(flipped_center)) * PREFIX(aspect_correction);
13 float dist = (length(normalized_pos) - PREFIX(inner_radius)) * PREFIX(pihalf_div_radius);
14 float linear_falloff = clamp(dist, 0.0, pihalf);
15 float falloff = cos(linear_falloff) * cos(linear_falloff);
16 x.rgb *= vec3(falloff);