#

API Docs for: 1.5.0
Show: Inherited Protected Private Deprecated

# File: src/pixi/filters/TwistFilter.js

    /**
     * @author Mat Groves http://matgroves.com/ @Doormat23
     */

    /**
     *
     * This filter applies a twist effect making display objects appear twisted in the given direction
     * @class TwistFilter
     * @contructor
     */
    PIXI.TwistFilter = function()
    {
        PIXI.AbstractFilter.call( this );

        this.passes = [this];

        // set the uniforms
        this.uniforms = {
            radius: {type: '1f', value:0.5},
            angle: {type: '1f', value:5},
            offset: {type: '2f', value:{x:0.5, y:0.5}},
        };

        this.fragmentSrc = [
            'precision mediump float;',
            'varying vec2 vTextureCoord;',
            'varying vec4 vColor;',
            'uniform vec4 dimensions;',
            'uniform sampler2D uSampler;',

            'uniform float radius;',
            'uniform float angle;',
            'uniform vec2 offset;',

            'void main(void) {',
            '   vec2 coord = vTextureCoord - offset;',
            '   float distance = length(coord);',

            '   if (distance < radius) {',
            '       float ratio = (radius - distance) / radius;',
            '       float angleMod = ratio * ratio * angle;',
            '       float s = sin(angleMod);',
            '       float c = cos(angleMod);',
            '       coord = vec2(coord.x * c - coord.y * s, coord.x * s + coord.y * c);',
            '   }',

            '   gl_FragColor = texture2D(uSampler, coord+offset);',
            '}'
        ];
    };

    PIXI.TwistFilter.prototype = Object.create( PIXI.AbstractFilter.prototype );
    PIXI.TwistFilter.prototype.constructor = PIXI.TwistFilter;

    /**
     *
     * This point describes the the offset of the twist
     * @property size
     * @type Point
     */
    Object.defineProperty(PIXI.TwistFilter.prototype, 'offset', {
        get: function() {
            return this.uniforms.offset.value;
        },
        set: function(value) {
            this.dirty = true;
            this.uniforms.offset.value = value;
        }
    });

    /**
     *
     * This radius describes size of the twist
     * @property size
     * @type Number
     */
    Object.defineProperty(PIXI.TwistFilter.prototype, 'radius', {
        get: function() {
            return this.uniforms.radius.value;
        },
        set: function(value) {
            this.dirty = true;
            this.uniforms.radius.value = value;
        }
    });

    /**
     *
     * This radius describes angle of the twist
     * @property angle
     * @type Number
     */
    Object.defineProperty(PIXI.TwistFilter.prototype, 'angle', {
        get: function() {
            return this.uniforms.angle.value;
        },
        set: function(value) {
            this.dirty = true;
            this.uniforms.angle.value = value;
        }
    });