playcanvas/build/playcanvas/src/scene/shader-lib/glsl/chunks/render-pass/frag/downsample.js

Open-source WebGL/WebGPU 3D engine for the web

var downsample_default = `
uniform sampler2D sourceTexture;
uniform vec2 sourceInvResolution;
varying vec2 uv0;
#ifdef PREMULTIPLY
	uniform sampler2D premultiplyTexture;
#endif
void main()
{
	vec3 e = texture2D (sourceTexture, uv0).rgb;
	#ifdef BOXFILTER
		vec3 value = e;
		#ifdef PREMULTIPLY
			float premultiply = texture2D(premultiplyTexture, uv0).{PREMULTIPLY_SRC_CHANNEL};
			value *= vec3(premultiply);
		#endif
	#else
		float x = sourceInvResolution.x;
		float y = sourceInvResolution.y;
		vec3 a = texture2D(sourceTexture, vec2 (uv0.x - 2.0 * x, uv0.y + 2.0 * y)).rgb;
		vec3 b = texture2D(sourceTexture, vec2 (uv0.x,		   uv0.y + 2.0 * y)).rgb;
		vec3 c = texture2D(sourceTexture, vec2 (uv0.x + 2.0 * x, uv0.y + 2.0 * y)).rgb;
		vec3 d = texture2D(sourceTexture, vec2 (uv0.x - 2.0 * x, uv0.y)).rgb;
		vec3 f = texture2D(sourceTexture, vec2 (uv0.x + 2.0 * x, uv0.y)).rgb;
		vec3 g = texture2D(sourceTexture, vec2 (uv0.x - 2.0 * x, uv0.y - 2.0 * y)).rgb;
		vec3 h = texture2D(sourceTexture, vec2 (uv0.x,		   uv0.y - 2.0 * y)).rgb;
		vec3 i = texture2D(sourceTexture, vec2 (uv0.x + 2.0 * x, uv0.y - 2.0 * y)).rgb;
		vec3 j = texture2D(sourceTexture, vec2 (uv0.x - x, uv0.y + y)).rgb;
		vec3 k = texture2D(sourceTexture, vec2 (uv0.x + x, uv0.y + y)).rgb;
		vec3 l = texture2D(sourceTexture, vec2 (uv0.x - x, uv0.y - y)).rgb;
		vec3 m = texture2D(sourceTexture, vec2 (uv0.x + x, uv0.y - y)).rgb;
		vec3 value = e * 0.125;
		value += (a + c + g + i) * 0.03125;
		value += (b + d + f + h) * 0.0625;
		value += (j + k + l + m) * 0.125;
	#endif
	#ifdef REMOVE_INVALID
		value = max(value, vec3(0.0));
	#endif
	gl_FragColor = vec4(value, 1.0);
}
`;
export {
	downsample_default as default
};