var core = require('../../core');
var glslify  = require('glslify');

/**
 * This filter applies a twist effect making display objects appear twisted in the given direction.
 *
 * @class
 * @extends PIXI.Filter
 * @memberof PIXI.filters
 */
function TwistFilter()
{
    core.Filter.call(this,
        // vertex shader
        glslify('../fragments/default.vert'),
        // fragment shader
        glslify('./twist.frag')
    );

    this.radius = 200;
    this.angle = 4;
    this.padding = 20;
}

TwistFilter.prototype = Object.create(core.Filter.prototype);
TwistFilter.prototype.constructor = TwistFilter;
module.exports = TwistFilter;

Object.defineProperties(TwistFilter.prototype, {
    /**
     * This point describes the the offset of the twist.
     *
     * @member {PIXI.Point}
     * @memberof PIXI.filters.TwistFilter#
     */
    offset: {
        get: function ()
        {
            return this.uniforms.offset;
        },
        set: function (value)
        {
            this.uniforms.offset = value;
        }
    },

    /**
     * This radius of the twist.
     *
     * @member {number}
     * @memberof PIXI.filters.TwistFilter#
     */
    radius: {
        get: function ()
        {
            return this.uniforms.radius;
        },
        set: function (value)
        {
            this.uniforms.radius = value;
        }
    },

    /**
     * This angle of the twist.
     *
     * @member {number}
     * @memberof PIXI.filters.TwistFilter#
     */
    angle: {
        get: function ()
        {
            return this.uniforms.angle;
        },
        set: function (value)
        {
            this.uniforms.angle = value;
        }
    }
});