phaser/Phaser/renderers/canvas/GroupRenderer.ts

/// <reference path="../../_definitions.ts" />

module Phaser.Renderer.Canvas {

    export class GroupRenderer {

        constructor(game: Phaser.Game) {
            this.game = game;
        }

        /**
         * The essential reference to the main game object
         */
        public game: Phaser.Game;

        //  Local rendering related temp vars to help avoid gc spikes through var creation
        private _ga: number = 1;
        private _sx: number = 0;
        private _sy: number = 0;
        private _sw: number = 0;
        private _sh: number = 0;
        private _dx: number = 0;
        private _dy: number = 0;
        private _dw: number = 0;
        private _dh: number = 0;
        private _fx: number = 1;
        private _fy: number = 1;
        private _sin: number = 0;
        private _cos: number = 1;

        public preRender(camera: Phaser.Camera, group: Phaser.Group) {

            if (group.visible == false || camera.transform.scale.x == 0 || camera.transform.scale.y == 0 || camera.texture.alpha < 0.1)
            {
                return false;
            }

            //  Reset our temp vars
            this._ga = -1;
            this._sx = 0;
            this._sy = 0;
            this._sw = group.texture.width;
            this._sh = group.texture.height;
            this._fx = group.transform.scale.x;
            this._fy = group.transform.scale.y;
            this._sin = 0;
            this._cos = 1;
            //this._dx = (camera.screenView.x * camera.scrollFactor.x) + camera.frameBounds.x - (camera.worldView.x * camera.scrollFactor.x);
            //this._dy = (camera.screenView.y * camera.scrollFactor.y) + camera.frameBounds.y - (camera.worldView.y * camera.scrollFactor.y);
            this._dx = 0;
            this._dy = 0;
            this._dw = group.texture.width;
            this._dh = group.texture.height;

            //  Global Composite Ops
            if (group.texture.globalCompositeOperation)
            {
                group.texture.context.save();
                group.texture.context.globalCompositeOperation = group.texture.globalCompositeOperation;
            }

            //  Alpha
            if (group.texture.alpha !== 1 && group.texture.context.globalAlpha !== group.texture.alpha)
            {
                this._ga = group.texture.context.globalAlpha;
                group.texture.context.globalAlpha = group.texture.alpha;
            }

            //  Flip X
            if (group.texture.flippedX)
            {
                this._fx = -group.transform.scale.x;
            }

            //  Flip Y
            if (group.texture.flippedY)
            {
                this._fy = -group.transform.scale.y;
            }

            //	Rotation and Flipped
            if (group.modified)
            {
                if (group.transform.rotation !== 0 || group.transform.rotationOffset !== 0)
                {
                    this._sin = Math.sin(group.game.math.degreesToRadians(group.transform.rotationOffset + group.transform.rotation));
                    this._cos = Math.cos(group.game.math.degreesToRadians(group.transform.rotationOffset + group.transform.rotation));
                }

                group.texture.context.save();

                group.texture.context.setTransform(
                    this._cos * this._fx,                               //  scale x
                    (this._sin * this._fx) + group.transform.skew.x,    //  skew x
                    -(this._sin * this._fy) + group.transform.skew.y,   //  skew y
                    this._cos * this._fy,                               //  scale y
                    this._dx,                                           //  translate x
                    this._dy                                            //  translate y
                    );

                this._dx = -group.transform.origin.x;
                this._dy = -group.transform.origin.y;
            }
            else
            {
                if (!group.transform.origin.equals(0))
                {
                    this._dx -= group.transform.origin.x;
                    this._dy -= group.transform.origin.y;
                }
            }

            this._sx = Math.floor(this._sx);
            this._sy = Math.floor(this._sy);
            this._sw = Math.floor(this._sw);
            this._sh = Math.floor(this._sh);
            this._dx = Math.floor(this._dx);
            this._dy = Math.floor(this._dy);
            this._dw = Math.floor(this._dw);
            this._dh = Math.floor(this._dh);

            if (group.texture.opaque)
            {
                group.texture.context.fillStyle = group.texture.backgroundColor;
                group.texture.context.fillRect(this._dx, this._dy, this._dw, this._dh);
            }

            if (group.texture.loaded)
            {
                group.texture.context.drawImage(
                    group.texture.texture,	    //	Source Image
                    this._sx, 			//	Source X (location within the source image)
                    this._sy, 			//	Source Y
                    this._sw, 			//	Source Width
                    this._sh, 			//	Source Height
                    this._dx, 			//	Destination X (where on the canvas it'll be drawn)
                    this._dy, 			//	Destination Y
                    this._dw, 			//	Destination Width (always same as Source Width unless scaled)
                    this._dh			//	Destination Height (always same as Source Height unless scaled)
                    );
            }

            return true;

        }

        public postRender(camera: Phaser.Camera, group: Phaser.Group) {

            if (group.modified || group.texture.globalCompositeOperation)
            {
                group.texture.context.restore();
            }

            if (this._ga > -1)
            {
                group.texture.context.globalAlpha = this._ga;
            }

        }

    }

}