Pixel-Composer/shaders/sh_de_stray/sh_de_stray.fsh
2024-05-29 13:34:44 +07:00

94 lines
2.5 KiB
GLSL

varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform vec2 dimension;
uniform float tolerance;
uniform int strict;
uniform int fill;
vec4 a4;
float d(in vec4 c1, in vec4 c2) { return length(c1 - c2) / sqrt(4.); }
bool s(in vec4 c1, in vec4 c2) { return d(c1, c2) <= tolerance; }
#region select closet color
vec4 sel2(in vec4 c0, in vec4 c1) {
float d0 = d(a4, c0);
float d1 = d(a4, c1);
float mn = min(d0, d1);
if(mn == d0) return c0;
return c1;
}
vec4 sel3(in vec4 c0, in vec4 c1, in vec4 c2) {
float d0 = d(a4, c0);
float d1 = d(a4, c1);
float d2 = d(a4, c2);
float mn = min(min(d0, d1), d2);
if(mn == d0) return c0;
if(mn == d1) return c1;
return c2;
}
vec4 sel4(in vec4 c0, in vec4 c1, in vec4 c2, in vec4 c3) {
float d0 = d(a4, c0);
float d1 = d(a4, c1);
float d2 = d(a4, c2);
float d3 = d(a4, c3);
float mn = min(min(d0, d1), min(d2, d3));
if(mn == d0) return c0;
if(mn == d1) return c1;
if(mn == d2) return c2;
return c3;
}
#endregion
void main() {
vec2 tx = 1. / dimension;
// 0 1 2
// 3 4 5
// 6 7 8
vec4 a0 = texture2D( gm_BaseTexture, v_vTexcoord + vec2(-tx.x, -tx.y));
vec4 a1 = texture2D( gm_BaseTexture, v_vTexcoord + vec2( 0., -tx.y));
vec4 a2 = texture2D( gm_BaseTexture, v_vTexcoord + vec2( tx.x, -tx.y));
vec4 a3 = texture2D( gm_BaseTexture, v_vTexcoord + vec2(-tx.x, 0.));
a4 = texture2D( gm_BaseTexture, v_vTexcoord );
vec4 a5 = texture2D( gm_BaseTexture, v_vTexcoord + vec2( tx.x, 0.));
vec4 a6 = texture2D( gm_BaseTexture, v_vTexcoord + vec2(-tx.x, tx.y));
vec4 a7 = texture2D( gm_BaseTexture, v_vTexcoord + vec2( 0., tx.y));
vec4 a8 = texture2D( gm_BaseTexture, v_vTexcoord + vec2( tx.x, tx.y));
gl_FragColor = a4;
if(a4.a == 0.) {
if(fill == 0) return;
gl_FragColor = sel4(a1, a3, a5, a7);
return;
}
if(strict == 0) {
if(!s(a4, a1) && s(a1, a3) && s(a1, a5)) gl_FragColor = sel3(a1, a3, a5);
if(!s(a4, a3) && s(a3, a1) && s(a3, a7)) gl_FragColor = sel3(a3, a1, a7);
if(!s(a4, a5) && s(a5, a1) && s(a5, a7)) gl_FragColor = sel3(a5, a1, a7);
if(!s(a4, a7) && s(a7, a3) && s(a7, a5)) gl_FragColor = sel3(a7, a3, a5);
} else if(strict == 1) {
if(!s(a4, a1) && s(a1, a3) && s(a1, a5) && s(a1, a7))
gl_FragColor = sel4(a1, a3, a5, a7);
} else if(strict == 2) {
if(!s(a4, a1) && s(a1, a3) && s(a1, a5) && s(a1, a7)
&& s(a1, a0) && s(a1, a2) && s(a1, a6) && s(a1, a8))
gl_FragColor = sel4(a1, a3, a5, a7);
}
}