phaser/filters/CausticLight.js

/**
* A sample demonstrating how to create new Phaser Filters.
*/
Phaser.Filter.SampleFilter = function (game) {

    Phaser.Filter.call(this, game);

    this.uniforms.divisor = { type: '1f', value: 0.5 };
        
    //  The fragment shader source
    this.fragmentSrc = [

        "precision mediump float;",
        "uniform vec3      resolution;",
        "uniform float     time;",

        "const int   complexity      = 40;    // More points of color.",
        "const float mouse_factor    = 25.0;  // Makes it more/less jumpy.",
        "const float mouse_offset    = 5.0;   // Drives complexity in the amount of curls/cuves.  Zero is a single whirlpool.",
        "const float fluid_speed     = 45.0;  // Drives speed, higher number will make it slower.",
        "const float color_intensity = 0.30;",

        "const float Pi = 3.14159;",

        "float sinApprox(float x) {",
            "x = Pi + (2.0 * Pi) * floor(x / (2.0 * Pi)) - x;",
            "return (4.0 / Pi) * x - (4.0 / Pi / Pi) * x * abs(x);",
        "}",

        "float cosApprox(float x) {",
            "return sinApprox(x + 0.5 * Pi);",
        "}",

        "void main()",
        "{",
            "vec2 p=(2.0*gl_FragCoord.xy-resolution)/max(resolution.x,resolution.y);",
            "for(int i=1;i<complexity;i++)",
            "{",
                "vec2 newp=p;",
                "newp.x+=0.6/float(i)*sin(float(i)*p.y+time/fluid_speed+0.3*float(i))+mouse.y/mouse_factor+mouse_offset;",
                "newp.y+=0.6/float(i)*sin(float(i)*p.x+time/fluid_speed+0.3*float(i+10))-mouse.x/mouse_factor+mouse_offset;",
                "p=newp;",
            "}",
            "vec3 col=vec3(color_intensity*sin(3.0*p.x)+color_intensity,color_intensity*sin(3.0*p.y)+color_intensity,color_intensity*sin(p.x+p.y)+color_intensity);",
            "gl_FragColor=vec4(col, 1.0);",
        "}"
    ];

};

Phaser.Filter.SampleFilter.prototype = Object.create(Phaser.Filter.prototype);
Phaser.Filter.SampleFilter.prototype.constructor = Phaser.Filter.SampleFilter;

Phaser.Filter.SampleFilter.prototype.init = function (width, height, divisor) {

    if (typeof divisor == 'undefined') { divisor = 0.5 };

    this.setResolution(width, height);
    this.uniforms.divisor.value = divisor;

}