Pixel-Composer/shaders/sh_twirl/sh_twirl.fsh
2022-12-27 10:00:50 +07:00

37 lines
911 B
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform vec2 dimension;
uniform vec2 center;
uniform float strength;
uniform float radius;
uniform int sampleMode;
vec4 sampleTexture(vec2 pos) {
if(pos.x > 0. && pos.y > 0. && pos.x < 1. && pos.y < 1.)
return texture2D(gm_BaseTexture, pos);
if(sampleMode == 0)
return vec4(0.);
if(sampleMode == 1)
return texture2D(gm_BaseTexture, clamp(pos, 0., 1.));
if(sampleMode == 2)
return texture2D(gm_BaseTexture, fract(pos));
return vec4(0.);
}
void main() {
vec2 pixelPos = v_vTexcoord * dimension;
vec2 to = pixelPos - center;
float dis = distance(center, pixelPos);
float eff = 1. - clamp(dis / radius, 0., 1.);
float ang = atan(to.y, to.x) + eff * strength;
vec2 tex = center + vec2(cos(ang), sin(ang)) * distance(center, pixelPos);
gl_FragColor = sampleTexture( tex / dimension );
}