#version 150 core | |
#define INVERSE_2PI 0.1591549430918953358 | |
uniform sampler2D gradTabTexture; | |
uniform float opacity; | |
uniform float angle; | |
in vec2 coord; | |
out vec4 fragColor; | |
void main() | |
{ | |
float t; | |
if (abs(coord.y) == abs(coord.x)) | |
t = (atan(-coord.y + 0.002, coord.x) + angle) * INVERSE_2PI; | |
else | |
t = (atan(-coord.y, coord.x) + angle) * INVERSE_2PI; | |
fragColor = texture(gradTabTexture, vec2(t - floor(t), 0.5)) * opacity; | |
} |