fbird/frameworks/cocos2d-html5/cocos2d/particle/CCParticleSystemCanvasRenderCmd.js

/****************************************************************************
 Copyright (c) 2013-2014 Chukong Technologies Inc.

 http://www.cocos2d-x.org

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
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 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 THE SOFTWARE.
 ****************************************************************************/

/**
 * ParticleSystem's canvas render command
 */
(function () {
    cc.ParticleSystem.CanvasRenderCmd = function (renderable) {
        this._rootCtor(renderable);
        this._needDraw = true;

        this._drawMode = cc.ParticleSystem.TEXTURE_MODE;
        this._shapeType = cc.ParticleSystem.BALL_SHAPE;

        this._pointRect = cc.rect(0, 0, 0, 0);
        this._tintCache = null;
    };
    var proto = cc.ParticleSystem.CanvasRenderCmd.prototype = Object.create(cc.Node.CanvasRenderCmd.prototype);
    proto.constructor = cc.ParticleSystem.CanvasRenderCmd;

    proto.getDrawMode = function () {
        return this._drawMode;
    };

    proto.setDrawMode = function (drawMode) {
        this._drawMode = drawMode;
    };

    proto.getShapeType = function () {
        return this._shapeType;
    };

    proto.setShapeType = function (shapeType) {
        this._shapeType = shapeType;
    };

    proto.setBatchNode = function (batchNode) {
        if (this._batchNode !== batchNode) {
            this._node._batchNode = batchNode;
        }
    };

    proto.updateQuadWithParticle = function (particle, newPosition) {
        //do nothing
    };

    proto.updateParticlePosition = function (particle, position) {
        cc.pIn(particle.drawPos, position);
    };

    proto.rendering = function (ctx, scaleX, scaleY) {
        //TODO: need refactor rendering for performance
        var wrapper = ctx || cc._renderContext, context = wrapper.getContext(),
            node = this._node, pointRect = this._pointRect;

        wrapper.setTransform(this._worldTransform, scaleX, scaleY);
        wrapper.save();
        if (node.isBlendAdditive())
            context.globalCompositeOperation = 'lighter';
        else
            context.globalCompositeOperation = 'source-over';

        var i, particle, lpx, alpha;
        var particleCount = this._node.particleCount, particles = this._node._particles;
        if (node.drawMode !== cc.ParticleSystem.SHAPE_MODE && node._texture) {
            // Delay drawing until the texture is fully loaded by the browser
            if (!node._texture._textureLoaded) {
                wrapper.restore();
                return;
            }
            var element = node._texture.getHtmlElementObj();
            if (!element.width || !element.height) {
                wrapper.restore();
                return;
            }

            var drawElement = element;
            for (i = 0; i < particleCount; i++) {
                particle = particles[i];
                lpx = (0 | (particle.size * 0.5));

                alpha = particle.color.a / 255;
                if (alpha === 0) continue;
                context.globalAlpha = alpha;

                context.save();
                context.translate((0 | particle.drawPos.x), -(0 | particle.drawPos.y));

                var size = Math.floor(particle.size / 4) * 4;
                var w = pointRect.width;
                var h = pointRect.height;

                context.scale(Math.max((1 / w) * size, 0.000001), Math.max((1 / h) * size, 0.000001));
                if (particle.rotation)
                    context.rotate(cc.degreesToRadians(particle.rotation));

                drawElement = particle.isChangeColor ? this._changeTextureColor(node._texture, particle.color, this._pointRect) : element;
                context.drawImage(drawElement, -(0 | (w / 2)), -(0 | (h / 2)));
                context.restore();
            }
        } else {
            var drawTool = cc._drawingUtil;
            for (i = 0; i < particleCount; i++) {
                particle = particles[i];
                lpx = (0 | (particle.size * 0.5));
                alpha = particle.color.a / 255;
                if (alpha === 0) continue;
                context.globalAlpha = alpha;

                context.save();
                context.translate(0 | particle.drawPos.x, -(0 | particle.drawPos.y));
                if (node.shapeType === cc.ParticleSystem.STAR_SHAPE) {
                    if (particle.rotation)
                        context.rotate(cc.degreesToRadians(particle.rotation));
                    drawTool.drawStar(wrapper, lpx, particle.color);
                } else
                    drawTool.drawColorBall(wrapper, lpx, particle.color);
                context.restore();
            }
        }
        wrapper.restore();
        cc.g_NumberOfDraws++;
    };

    proto._changeTextureColor = function (texture, color, rect) {
        if (!this._tintCache) {
            this._tintCache = document.createElement("canvas");
        }
        var tintCache = this._tintCache;
        var textureContentSize = texture.getContentSize();
        tintCache.width = textureContentSize.width;
        tintCache.height = textureContentSize.height;
        return texture._generateColorTexture(color.r, color.g, color.b, rect, tintCache);
    };

    proto.initTexCoordsWithRect = function (pointRect) {
        this._pointRect = pointRect;
    };

    proto.setTotalParticles = function (tp) {
        //cc.assert(tp <= this._allocatedParticles, "Particle: resizing particle array only supported for quads");
        this._node._totalParticles = (tp < 200) ? tp : 200;
    };

    proto.addParticle = function () {
        var node = this._node,
            particles = node._particles,
            particle;
        if (node.particleCount < particles.length) {
            particle = particles[node.particleCount];
        } else {
            particle = new cc.Particle();
            particles.push(particle);
        }
        return particle;
    };

    proto._setupVBO = function () {
    };
    proto._allocMemory = function () {
        return true;
    };

    proto.postStep = function () {
    };

    proto._setBlendAdditive = function () {
        var locBlendFunc = this._node._blendFunc;
        locBlendFunc.src = cc.BLEND_SRC;
        locBlendFunc.dst = cc.BLEND_DST;
    };

    proto._initWithTotalParticles = function (totalParticles) {
    };
    proto._updateDeltaColor = function (selParticle, dt) {
        if (!this._node._dontTint) {
            var deltaColor = selParticle.deltaColor;
            selParticle.color.r += deltaColor.r * dt;
            selParticle.color.g += deltaColor.g * dt;
            selParticle.color.b += deltaColor.b * dt;
            selParticle.color.a += deltaColor.a * dt;
            selParticle.isChangeColor = deltaColor.r !== 0 || deltaColor.g !== 0 || deltaColor.b !== 0;
        }
    };
})();