phaser/filters/Tunnel.js
2014-03-25 14:56:04 -07:00

71 lines
1.9 KiB
JavaScript

/**
* Original shader by 4rknova (https://www.shadertoy.com/view/lssGDn)
* Tweaked, uniforms added and converted to Phaser/PIXI by Richard Davey
*/
Phaser.Filter.Tunnel = function (game) {
Phaser.Filter.call(this, game);
this.uniforms.alpha = { type: '1f', value: 1 }
this.uniforms.origin = { type: '1f', value: 2.0 }
this.uniforms.iChannel0 = { type: 'sampler2D', value: null, textureData: { repeat: true } }
this.fragmentSrc = [
"precision mediump float;",
"uniform vec2 resolution;",
"uniform float time;",
"uniform sampler2D iChannel0;",
"uniform float alpha;",
"uniform float origin;",
"#define S 0.79577471545 // Precalculated 2.5 / PI",
"#define E 0.0001",
"void main(void)",
"{",
"vec2 p = (origin * gl_FragCoord.xy / resolution.xy - 1.0) * vec2(resolution.x / resolution.y, 1.0);",
"vec2 t = vec2(S * atan(p.x, p.y), 1.0 / max(length(p), E));",
"vec3 c = texture2D(iChannel0, t + vec2(time * 0.1, time)).xyz;",
"gl_FragColor = vec4(c / (t.y + 0.5), alpha);",
"}"
];
};
Phaser.Filter.Tunnel.prototype = Object.create(Phaser.Filter.prototype);
Phaser.Filter.Tunnel.prototype.constructor = Phaser.Filter.Tunnel;
Phaser.Filter.Tunnel.prototype.init = function (width, height, texture) {
this.setResolution(width, height);
this.uniforms.iChannel0.value = texture;
texture.baseTexture._powerOf2 = true;
}
Object.defineProperty(Phaser.Filter.Tunnel.prototype, 'alpha', {
get: function() {
return this.uniforms.alpha.value;
},
set: function(value) {
this.uniforms.alpha.value = value;
}
});
Object.defineProperty(Phaser.Filter.Tunnel.prototype, 'origin', {
get: function() {
return this.uniforms.origin.value;
},
set: function(value) {
this.uniforms.origin.value = value;
}
});