Pixel-Composer/shaders/sh_alpha_hash/sh_alpha_hash.fsh

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2023-01-01 02:06:02 +01:00
//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform sampler2D map;
uniform vec2 mapDimension;
uniform int useMap;
uniform vec2 dimension;
uniform float ditherSize;
uniform float dither[64];
void main() {
vec4 c = texture2D( gm_BaseTexture, v_vTexcoord );
if(c.a == 1.) {
gl_FragColor = c;
return;
}
vec2 pos = floor(v_vTexcoord * dimension);
float val;
if(useMap == 0) {
float col = mod(pos.x, ditherSize);
float row = mod(pos.y, ditherSize);
val = dither[int(row * ditherSize + col)] / (ditherSize * ditherSize - 1.);
} else {
float col = mod(pos.x, mapDimension.x);
float row = mod(pos.y, mapDimension.y);
vec4 map_data = texture2D( map, vec2(col, row) / mapDimension );
val = dot(map_data.rgb, vec3(0.2126, 0.7152, 0.0722));
}
c.a = c.a > val? 1. : 0.;
gl_FragColor = c;
}