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


/**
 * A set of functions used by the canvas renderer to draw the primitive graphics data
 *
 * @class CanvasGraphics
 */
PIXI.CanvasGraphics = function()
{

};


/*
 * Renders the graphics object
 *
 * @static
 * @private
 * @method renderGraphics
 * @param graphics {Graphics} the actual graphics object to render
 * @param context {Context2D} the 2d drawing method of the canvas
 */
PIXI.CanvasGraphics.renderGraphics = function(graphics, context)
{
    var worldAlpha = graphics.worldAlpha;
    var color = '';

    for (var i = 0; i < graphics.graphicsData.length; i++)
    {
        var data = graphics.graphicsData[i];
        var points = data.points;

        context.strokeStyle = color = '#' + ('00000' + ( data.lineColor | 0).toString(16)).substr(-6);

        context.lineWidth = data.lineWidth;

        if(data.type === PIXI.Graphics.POLY)
        {
            context.beginPath();

            context.moveTo(points[0], points[1]);

            for (var j=1; j < points.length/2; j++)
            {
                context.lineTo(points[j * 2], points[j * 2 + 1]);
            }

            // if the first and last point are the same close the path - much neater :)
            if(points[0] === points[points.length-2] && points[1] === points[points.length-1])
            {
                context.closePath();
            }

            if(data.fill)
            {
                context.globalAlpha = data.fillAlpha * worldAlpha;
                context.fillStyle = color = '#' + ('00000' + ( data.fillColor | 0).toString(16)).substr(-6);
                context.fill();
            }
            if(data.lineWidth)
            {
                context.globalAlpha = data.lineAlpha * worldAlpha;
                context.stroke();
            }
        }
        else if(data.type === PIXI.Graphics.RECT)
        {

            if(data.fillColor || data.fillColor === 0)
            {
                context.globalAlpha = data.fillAlpha * worldAlpha;
                context.fillStyle = color = '#' + ('00000' + ( data.fillColor | 0).toString(16)).substr(-6);
                context.fillRect(points[0], points[1], points[2], points[3]);

            }
            if(data.lineWidth)
            {
                context.globalAlpha = data.lineAlpha * worldAlpha;
                context.strokeRect(points[0], points[1], points[2], points[3]);
            }

        }
        else if(data.type === PIXI.Graphics.CIRC)
        {
            // TODO - need to be Undefined!
            context.beginPath();
            context.arc(points[0], points[1], points[2],0,2*Math.PI);
            context.closePath();

            if(data.fill)
            {
                context.globalAlpha = data.fillAlpha * worldAlpha;
                context.fillStyle = color = '#' + ('00000' + ( data.fillColor | 0).toString(16)).substr(-6);
                context.fill();
            }
            if(data.lineWidth)
            {
                context.globalAlpha = data.lineAlpha * worldAlpha;
                context.stroke();
            }
        }
        else if(data.type === PIXI.Graphics.ELIP)
        {

            // ellipse code taken from: http://stackoverflow.com/questions/2172798/how-to-draw-an-oval-in-html5-canvas

            var ellipseData =  data.points;

            var w = ellipseData[2] * 2;
            var h = ellipseData[3] * 2;

            var x = ellipseData[0] - w/2;
            var y = ellipseData[1] - h/2;

            context.beginPath();

            var kappa = 0.5522848,
                ox = (w / 2) * kappa, // control point offset horizontal
                oy = (h / 2) * kappa, // control point offset vertical
                xe = x + w,           // x-end
                ye = y + h,           // y-end
                xm = x + w / 2,       // x-middle
                ym = y + h / 2;       // y-middle

            context.moveTo(x, ym);
            context.bezierCurveTo(x, ym - oy, xm - ox, y, xm, y);
            context.bezierCurveTo(xm + ox, y, xe, ym - oy, xe, ym);
            context.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
            context.bezierCurveTo(xm - ox, ye, x, ym + oy, x, ym);

            context.closePath();

            if(data.fill)
            {
                context.globalAlpha = data.fillAlpha * worldAlpha;
                context.fillStyle = color = '#' + ('00000' + ( data.fillColor | 0).toString(16)).substr(-6);
                context.fill();
            }
            if(data.lineWidth)
            {
                context.globalAlpha = data.lineAlpha * worldAlpha;
                context.stroke();
            }
        }
    }
};

/*
 * Renders a graphics mask
 *
 * @static
 * @private
 * @method renderGraphicsMask
 * @param graphics {Graphics} the graphics which will be used as a mask
 * @param context {Context2D} the context 2d method of the canvas
 */
PIXI.CanvasGraphics.renderGraphicsMask = function(graphics, context)
{
    var len = graphics.graphicsData.length;

    if(len === 0) return;

    if(len > 1)
    {
        len = 1;
        window.console.log('Pixi.js warning: masks in canvas can only mask using the first path in the graphics object');
    }

    for (var i = 0; i < 1; i++)
    {
        var data = graphics.graphicsData[i];
        var points = data.points;

        if(data.type === PIXI.Graphics.POLY)
        {
            context.beginPath();
            context.moveTo(points[0], points[1]);

            for (var j=1; j < points.length/2; j++)
            {
                context.lineTo(points[j * 2], points[j * 2 + 1]);
            }

            // if the first and last point are the same close the path - much neater :)
            if(points[0] === points[points.length-2] && points[1] === points[points.length-1])
            {
                context.closePath();
            }

        }
        else if(data.type === PIXI.Graphics.RECT)
        {
            context.beginPath();
            context.rect(points[0], points[1], points[2], points[3]);
            context.closePath();
        }
        else if(data.type === PIXI.Graphics.CIRC)
        {
            // TODO - need to be Undefined!
            context.beginPath();
            context.arc(points[0], points[1], points[2],0,2*Math.PI);
            context.closePath();
        }
        else if(data.type === PIXI.Graphics.ELIP)
        {

            // ellipse code taken from: http://stackoverflow.com/questions/2172798/how-to-draw-an-oval-in-html5-canvas
            var ellipseData =  data.points;

            var w = ellipseData[2] * 2;
            var h = ellipseData[3] * 2;

            var x = ellipseData[0] - w/2;
            var y = ellipseData[1] - h/2;

            context.beginPath();

            var kappa = 0.5522848,
                ox = (w / 2) * kappa, // control point offset horizontal
                oy = (h / 2) * kappa, // control point offset vertical
                xe = x + w,           // x-end
                ye = y + h,           // y-end
                xm = x + w / 2,       // x-middle
                ym = y + h / 2;       // y-middle

            context.moveTo(x, ym);
            context.bezierCurveTo(x, ym - oy, xm - ox, y, xm, y);
            context.bezierCurveTo(xm + ox, y, xe, ym - oy, xe, ym);
            context.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
            context.bezierCurveTo(xm - ox, ye, x, ym + oy, x, ym);
            context.closePath();
        }
    }
};
