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