Pixel-Composer/shaders/sh_bevel/sh_bevel.fsh
2022-12-21 08:30:23 +07:00

50 lines
1.2 KiB
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform vec2 dimension;
uniform vec2 scale;
uniform vec2 shift;
uniform float height;
#define TAU 6.28318
float bright(in vec4 col) {
return dot(col.rgb, vec3(0.2126, 0.7152, 0.0722)) * col.a;
}
void main() {
vec2 pixelStep = 1. / dimension;
float tauDiv = TAU / 32.;
vec4 col = texture2D(gm_BaseTexture, v_vTexcoord);
gl_FragColor = col;
bool done = false;
float shift_angle = atan(shift.y, shift.x);
float shift_distance = length(shift);
float min_distance = 999.;
if(bright(col) > 0.) {
for(float i = 1.; i < height; i++) {
for(float j = 0.; j < 32.; j++) {
float ang = j * tauDiv;
float added_distance = 1. + cos(abs(shift_angle - ang)) * shift_distance;
vec2 shf = vec2( cos(ang), sin(ang)) * (i * added_distance) / scale;
vec2 pxs = v_vTexcoord + shf * pixelStep;
vec4 sam = v_vColour * texture2D( gm_BaseTexture, pxs );
if(bright(sam) < 1. || pxs.x < 0. || pxs.y < 0. || pxs.x > 1. || pxs.y > 1.) {
float dist1 = i;
min_distance = min(min_distance, dist1);
break;
}
}
}
gl_FragColor = vec4(vec3(min_distance / height), col.a);
}
}