/**
 * A standard object to store the Uvs of a texture
 *
 * @class
 * @private
 * @memberof PIXI
 */
function TextureUvs()
{
    this.x0 = 0;
    this.y0 = 0;

    this.x1 = 1;
    this.y1 = 0;

    this.x2 = 1;
    this.y2 = 1;

    this.x3 = 0;
    this.y3 = 1;
}

module.exports = TextureUvs;

var GroupD8 = require('../math/GroupD8');

/**
 * Sets the texture Uvs based on the given frame information
 * @param frame {PIXI.Rectangle}
 * @param baseFrame {PIXI.Rectangle}
 * @param rotate {number} Rotation of frame, see {@link PIXI.GroupD8}
 * @private
 */
TextureUvs.prototype.set = function (frame, baseFrame, rotate)
{
    var tw = baseFrame.width;
    var th = baseFrame.height;

    if(rotate)
    {
        //width and height div 2 div baseFrame size
        var swapWidthHeight = GroupD8.isSwapWidthHeight(rotate);
        var w2 = (swapWidthHeight ? frame.height : frame.width) / 2 / tw;
        var h2 = (swapWidthHeight ? frame.width : frame.height) / 2 / th;
        //coordinates of center
        var cX = frame.x / tw + w2;
        var cY = frame.y / th + h2;
        rotate = GroupD8.add(rotate, GroupD8.NW); //NW is top-left corner
        this.x0 = cX + w2 * GroupD8.uX(rotate);
        this.y0 = cY + h2 * GroupD8.uY(rotate);
        rotate = GroupD8.add(rotate, 2); //rotate 90 degrees clockwise
        this.x1 = cX + w2 * GroupD8.uX(rotate);
        this.y1 = cY + h2 * GroupD8.uY(rotate);
        rotate = GroupD8.add(rotate, 2);
        this.x2 = cX + w2 * GroupD8.uX(rotate);
        this.y2 = cY + h2 * GroupD8.uY(rotate);
        rotate = GroupD8.add(rotate, 2);
        this.x3 = cX + w2 * GroupD8.uX(rotate);
        this.y3 = cY + h2 * GroupD8.uY(rotate);
    }
    else
    {

        this.x0 = frame.x / tw;
        this.y0 = frame.y / th;

        this.x1 = (frame.x + frame.width) / tw;
        this.y1 = frame.y / th;

        this.x2 = (frame.x + frame.width) / tw;
        this.y2 = (frame.y + frame.height) / th;

        this.x3 = frame.x / tw;
        this.y3 = (frame.y + frame.height) / th;
    }
};