Portal Shader

by roomyrooms

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/pixi.js/5.2.2/pixi.min.js"></script>

<script type="x-data-url" id="tree-url">
 ...

JavaScript

var treeUrl = document.getElementById('tree-url').textContent;
var punchUrl = document.getElementById('punch-url').textContent;

var fragmentShader = `
precision mediump float;

varying vec2 vTextureCoord;

uniform sampler2D uSampler;
uniform highp vec4 inputSize;
uniform highp vec4 outputFrame;
uniform sampler2D uAstral;
uniform float time;

vec2 mapCoord( vec2 coord )
{
    coord *= inputSize.xy;
    coord += inputSize.zw;

    return coord;
}

vec2 unmapCoord( vec2 coord )
{
    coord -= inputSize.zw;
    coord /= inputSize.xy;

    return coord;
}

void main() {
  vec4 newcol = texture2D(uSampler, vTextureCoord);
  vec2 coord = vec2(mod(vTextureCoord.x+time*0.000001, 0.5), vTextureCoord.y);
  vec2 real = mapCoord(coord);
  
  float wavewidth = 0.004;
  coord += fract(time*0.005);
  float blackval = distance(newcol.rgb, vec3(0.6,0.898,0.314));
  if (blackval <= 0.05 && newcol.a > 0.1) {
		newcol = texture2D(uAstral, coord/vec2(0.5));
  	newcol *= 1.0-smoothstep(0.57, 0.69, vTextureCoord.y);
	}
  gl_FragColor = newcol;
}`

function defaultValue(inputValue, defaultValue) {
    inputValue = typeof inputValue !== 'undefined' ? inputValue : defaultValue;
    return inputValue;
}

function AstralFilter(uTex) {
    PIXI.Filter.call(this,undefined,fragmentShader);
    this.uniforms.uAstral = uTex;
    this.uniforms.time = performance.now();
}

AstralFilter.prototype = Object.create(PIXI.Filter.prototype);
AstralFilter.prototype.constructor = AstralFilter;

AstralFilter.prototype.apply = function (filterManager, input, output, clear) {
		clear = PIXI.CLEAR_MODES;
    this.padding = 5;
    this.uniforms.time = performance.now();
    // draw the filter...
    filterManager.applyFilter(this, input, output);
}

PIXI.settings.MIPMAP_TEXTURES = PIXI.MIPMAP_MODES.ON;
var stage = new PIXI.Container();

// create a renderer instance.
var renderer = PIXI.autoDetectRenderer(512, 512);
renderer.roundPixels = true;
PIXI.settings.SCALE_MODE = PIXI.SCALE_MODES.NEAREST;

// tex...