@animech-public/playcanvas/build/playcanvas.prf/src/extras/render-passes/render-pass-downsample.js

PlayCanvas WebGL game engine

import { RenderPassShaderQuad } from '../../scene/graphics/render-pass-shader-quad.js';

class RenderPassDownsample extends RenderPassShaderQuad {
	constructor(device, sourceTexture) {
		super(device);
		this.sourceTexture = sourceTexture;
		this.shader = this.createQuadShader('DownSampleShader', `
			uniform sampler2D sourceTexture;
			uniform vec2 sourceInvResolution;
			varying vec2 uv0;
			void main()
			{
				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 e = texture2D (sourceTexture, vec2 (uv0.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;
				gl_FragColor = vec4(value, 1.0);
			}`);
		this.sourceTextureId = device.scope.resolve('sourceTexture');
		this.sourceInvResolutionId = device.scope.resolve('sourceInvResolution');
		this.sourceInvResolutionValue = new Float32Array(2);
	}
	execute() {
		this.sourceTextureId.setValue(this.sourceTexture);
		this.sourceInvResolutionValue[0] = 1.0 / this.sourceTexture.width;
		this.sourceInvResolutionValue[1] = 1.0 / this.sourceTexture.height;
		this.sourceInvResolutionId.setValue(this.sourceInvResolutionValue);
		super.execute();
	}
}

export { RenderPassDownsample };