CocosCreator2.1.0渲染流程与shader

CocosCreator2.1.0版本正式支持导入3D模型

对于2.5D游戏的开发来说有着重要意义

自己此前在写捕鱼游戏时了解过自定义shader

并实现了4种不同的水波效果

但经过CocosCreator版本的不断升级

尤其是1.10和2.0两个版本

旧的渲染器被抛弃了

因此老的shader特效也全都不能用了

直到最近正好有时间，花了几天把原先写的特效升级到了最新的2.1.0版本

下面记录一下自定义shader实现方法的改变

以及新的渲染器的理解

过往自定义shader的实现依赖

cc.gl

cc.GLProgram

cc.GLProgramState

CCSprite._sgNode

CCTexture2D.setTexParameters

这些统统都不能用了！

取而代之的是新的渲染结构

显然又是多层封装咯

最上层的material关联到sprite组件

最底层的pass关联到具体的vert和frag着色器代码，也就是Shader层

其实Shader层才应该是最底层的

从底向上一层层来看

Shader

系统默认的shader是通过以下方法保存在lib对象中的

ProgramLib.prototype.define = function define (name, vert, frag, defines) {

而lib对象所在的位置比较奇怪，可能往后的版本会变更

cc.renderer._forward._programLib

着色器代码也需要稍作修改

以往的CC_Texture0等固定变量都不存在了

Pass

Pass的构造函数传入的name就是与着色器同名的name

所以Pass是直接关联shader的

另外Pass还包含了混合参数、深度测试参数、模板测试参数等等

Base.prototype._draw = function _draw (item) {var this$1 = this;var device = this._device;var programLib = this._programLib;var node = item.node;var ia = item.ia;var effect = item.effect;var technique = item.technique;var defines = item.defines;// reset the pool// NOTE: we can use drawCounter optimize this// TODO: should be configurable
  _float2_pool.reset();_float3_pool.reset();_float4_pool.reset();_float9_pool.reset();_float16_pool.reset();_float64_pool.reset();_int2_pool.reset();_int3_pool.reset();_int4_pool.reset();_int64_pool.reset();// set common uniforms// TODO: try commit this depends on effect// {node.getWorldMatrix(_m4_tmp$2);device.setUniform('model', mat4.array(_float16_pool.add(), _m4_tmp$2));var inverse = mat3.invert(_m3_tmp$1, mat3.fromMat4(_m3_tmp$1, _m4_tmp$2));if (inverse) {mat3.transpose(_m3_tmp$1, inverse);device.setUniform('normalMatrix', mat3.array(_float9_pool.add(), _m3_tmp$1));}// }// set technique uniformsfor (var i = 0; i < technique._parameters.length; ++i) {
    // 这里遍历technique._parameters
    // 再从effect找到参数的值
    // 因此参数必须在technique中声明并同时在effect中定义
    // 若不在technique中声明，则不会遍历不会走到device.setUniform这一步
var prop = technique._parameters[i];var param = effect.getProperty(prop.name);// 若未在effect中赋值，则从technique中找默认if (param === undefined) {param = prop.val;}// 默认也找不到，就给个该类型的default值if (param === undefined) {param = this$1._type2defaultValue[prop.type];}if (param === undefined) {console.warn(("Failed to set technique property " + (prop.name) + ", value not found."));continue;}if (prop.type === enums.PARAM_TEXTURE_2D ||prop.type === enums.PARAM_TEXTURE_CUBE) {if (prop.size !== undefined) {if (prop.size !== param.length) {console.error(("The length of texture array (" + (param.length) + ") is not corrent(expect " + (prop.size) + ")."));continue;}var slots = _int64_pool.add();for (var index = 0; index < param.length; ++index) {slots[index] = this$1._allocTextuerUnit();}device.setTextureArray(prop.name, param, slots);} else {device.setTexture(prop.name, param, this$1._allocTextuerUnit());}} else {var convertedValue = (void 0);if (param instanceof Float32Array || param instanceof Int32Array) {convertedValue = param;}else if (prop.size !== undefined) {var convertArray = _type2uniformArrayValue[prop.type];if (convertArray.func === undefined) {console.error('Uniform array of color3/int3/float3/mat3 can not be supportted!');continue;}if (prop.size * convertArray.size > 64) {console.error('Uniform array is too long!');continue;}convertedValue = convertArray.func(param);} else {var convertFn = _type2uniformValue[prop.type];convertedValue = convertFn(param);}device.setUniform(prop.name, convertedValue);}}// for each passfor (var i$1 = 0; i$1 < technique._passes.length; ++i$1) {var pass = technique._passes[i$1];var count = ia.getPrimitiveCount();// set vertex bufferdevice.setVertexBuffer(0, ia._vertexBuffer);// set index bufferif (ia._indexBuffer) {device.setIndexBuffer(ia._indexBuffer);}// set primitive type
    device.setPrimitiveType(ia._primitiveType);// set program (通过pass里保存的program名字找到着色器program！)var program = programLib.getProgram(pass._programName, defines);device.setProgram(program);// cull mode
    device.setCullMode(pass._cullMode);// blendif (pass._blend) {device.enableBlend();device.setBlendFuncSep(pass._blendSrc,pass._blendDst,pass._blendSrcAlpha,pass._blendDstAlpha);device.setBlendEqSep(pass._blendEq,pass._blendAlphaEq);device.setBlendColor32(pass._blendColor);}// depth test & writeif (pass._depthTest) {device.enableDepthTest();device.setDepthFunc(pass._depthFunc);}if (pass._depthWrite) {device.enableDepthWrite();}// stencilif (pass._stencilTest) {device.enableStencilTest();// front
      device.setStencilFuncFront(pass._stencilFuncFront,pass._stencilRefFront,pass._stencilMaskFront);device.setStencilOpFront(pass._stencilFailOpFront,pass._stencilZFailOpFront,pass._stencilZPassOpFront,pass._stencilWriteMaskFront);// back
      device.setStencilFuncBack(pass._stencilFuncBack,pass._stencilRefBack,pass._stencilMaskBack);device.setStencilOpBack(pass._stencilFailOpBack,pass._stencilZFailOpBack,pass._stencilZPassOpBack,pass._stencilWriteMaskBack);}// draw pass
    device.draw(ia._start, count);this$1._resetTextuerUnit();}
};

Technique

Technique的构造函数如下

var Technique = function Technique(stages, parameters, passes, layer) {

stages不太了解

parameters声明了注入shader代码中的参数名和类型

未声明的参数即使写在shader里面也是无法使用的

passes可以指定多个，是否意味着多次渲染

以下是默认的SpriteMaterial中的Technique

var mainTech = new renderer.Technique(['transparent'],[{ name: 'texture', type: renderer.PARAM_TEXTURE_2D },{ name: 'color', type: renderer.PARAM_COLOR4 } ],[pass]
);

可以看到只设置了两个参数

因此在着色器中可以使用texture纹理采样

同时使用节点颜色color

Effect

Effect的构造函数如下

var Effect = function Effect(techniques, properties, defines) {

以下是默认的SpriteMaterial中的Effect

this._effect = new renderer.Effect([mainTech ],{'color': this._color},[{ name: 'useTexture', value: true },{ name: 'useModel', value: false },{ name: 'alphaTest', value: false },{ name: 'useColor', value: true } ]
);

在自定义材质中properties直接传空对象{}即可

如果是不变的uniform参数可以在technique中赋值默认val

如果是变化的uniform参数，如time、衰减因子、点击位置等等

通过以下方法来更新变量的值即可

Effect.prototype.setProperty = function setProperty (name, value) {

Material

自定义材质可以继承自默认材质

也可以类比SpriteMaterial来写

但我觉得那样太麻烦了，直接继承Material把几个有用的参数填进去就行了

而材质与sprite的绑定也简化为两行代码

原本CCSprite._activateMaterial统统省去

当纹理和顶点信息不改变的情况下

我认为以下两句是可以省略的

this.markForUpdateRenderData(true);

this.markForRender(true);

并且在h5、微信、安卓原生平台均验证有效

class CustomMaterial extends cc.renderer.renderEngine.Material{constructor(name , vert , frag , uniforms = [] , defines = []){super(false);this.name = namelet lib = cc.renderer._forward._programLib;!lib._templates[name] && lib.define(name, vert, frag, defines);this.init(name , uniforms);}use(sprite){// cc.dynamicAtlasManager.enabled = false;// 设置基本纹理和颜色let texture = sprite.spriteFrame.getTexture();let color = sprite.node.colorthis.setTexture(texture);this.setUniform('color' , { r: color.r / 255, g: color.g / 255, b: color.b / 255, a: sprite.node.opacity / 255 })this.updateHash();// 指定sprite的材质sprite._material = this;sprite._renderData._material = this;sprite._state = cc.Sprite.State.CUSTOM;}init(name , uniforms) {let renderer = cc.renderer.renderEngine.renderer;let gfx = cc.renderer.renderEngine.gfx;let pass = new renderer.Pass(name);pass.setDepth(false, false);pass.setCullMode(gfx.CULL_NONE);pass.setBlend(gfx.BLEND_FUNC_ADD,gfx.BLEND_SRC_ALPHA, gfx.BLEND_ONE_MINUS_SRC_ALPHA,gfx.BLEND_FUNC_ADD,gfx.BLEND_SRC_ALPHA, gfx.BLEND_ONE_MINUS_SRC_ALPHA);let mainTech = new renderer.Technique(['transparent'],[...uniforms,{ name: 'texture', type: renderer.PARAM_TEXTURE_2D /*, val : '默认值'*/},{ name: 'color', type: renderer.PARAM_COLOR4 /*, val : '默认值'*/},],[pass]);this._texture = null;this._effect = this.effect = new renderer.Effect([mainTech], {}, []);this._mainTech = mainTech;}
};

Render

可渲染节点如包含CCSprite组件的node

渲染组件CCSprite继承自RenderComponent

渲染组件onEnable时会为node赋值渲染组件的索引

this.node._renderComponent = this;

CCDirector.mainLoop中发起渲染命令

RenderComponentWalker.visit遍历场景节点

RenderFlow._children方法中会过滤点！active和全透明的节点

if (!c._activeInHierarchy || c._opacity === 0) continue;

RenderComponentWalker._commitComp中比较material的hash值

这也是updateHash的意义所在（若不调用updateHash很可能会报错，比如当节点是首个渲染节点时）

若hash值相同会使用上一个材质（流水线操作）

    _commitComp (comp, assembler, cullingMask) {if (this.material._hash !== comp._material._hash || this.cullingMask !== cullingMask) {this._flush();this.node = assembler.useModel ? comp.node : this._dummyNode;this.material = comp._material;this.cullingMask = cullingMask;}assembler.fillBuffers(comp, this);},