import GroupD8 from '../math/GroupD8';

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

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

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

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

        this.uvsUint32 = new Uint32Array(4);
    }

    /**
     * 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
     */
    set(frame, baseFrame, rotate)
    {
        const tw = baseFrame.width;
        const th = baseFrame.height;

        if(rotate)
        {
            //width and height div 2 div baseFrame size
            let w2 = frame.width / 2 / tw;
            let h2 = frame.height / 2 / th;
            //coordinates of center
            let cX = frame.x / tw + w2;
            let 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;
        }

        this.uvsUint32[0] = (((this.y0 * 65535) & 0xFFFF) << 16) | ((this.x0 * 65535) & 0xFFFF);
        this.uvsUint32[1] = (((this.y1 * 65535) & 0xFFFF) << 16) | ((this.x1 * 65535) & 0xFFFF);
        this.uvsUint32[2] = (((this.y2 * 65535) & 0xFFFF) << 16) | ((this.x2 * 65535) & 0xFFFF);
        this.uvsUint32[3] = (((this.y3 * 65535) & 0xFFFF) << 16) | ((this.x3 * 65535) & 0xFFFF);
    }
}

export default TextureUvs;