text: /****************************************************************************
   Copyright (c) 2013-2016 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
   furnished to do so, subject to the following conditions:
  
   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,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   THE SOFTWARE.
   ****************************************************************************/
  
  cc.rendererWebGL = (function () {
  
  // Internal variables
      // Batching general informations
  var _batchedInfo = {
          // The batched texture, all batching element should have the same texture
          texture: null,
          // The batched blend source, all batching element should have the same blend source
          blendSrc: null,
          // The batched blend destination, all batching element should have the same blend destination
          blendDst: null,
          // The batched shader, all batching element should have the same shader
          shader: null
      },
  
      _quadIndexBuffer = null,
      _quadVertexBuffer = null,
      // Total vertex size
      _vertexSize = 0,
      // Current batching vertex size
      _batchingSize = 0,
      _sizePerVertex = 6,
      // buffer data and views
      _vertexData = null,
      _vertexDataSize = 0,
      _vertexDataF32 = null,
      _vertexDataUI32 = null,
      _IS_IOS = false;
  
  
  // Inspired from @Heishe's gotta-batch-them-all branch
  // https://github.com/Talisca/cocos2d-html5/commit/de731f16414eb9bcaa20480006897ca6576d362c
  function updateQuadBuffer (numQuads) {
      var gl = cc._renderContext;
      // Update index buffer and fill up
      if (_quadIndexBuffer) {
          gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, _quadIndexBuffer);
  
          var indices = new Uint16Array(numQuads * 6);
          var currentQuad = 0;
          for (var i = 0, len = numQuads * 6; i < len; i += 6) {
              indices[i] = currentQuad + 0;
              indices[i + 1] = currentQuad + 1;
              indices[i + 2] = currentQuad + 2;
              indices[i + 3] = currentQuad + 1;
              indices[i + 4] = currentQuad + 2;
              indices[i + 5] = currentQuad + 3;
              currentQuad += 4;
          }
          gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
      }
  
      if (_quadVertexBuffer) {
          _vertexDataSize = numQuads * 4 * _sizePerVertex;
          var byteLength = _vertexDataSize * 4;
          _vertexData = new ArrayBuffer(byteLength);
          _vertexDataF32 = new Float32Array(_vertexData);
          _vertexDataUI32 = new Uint32Array(_vertexData);
          // Init buffer data
          gl.bindBuffer(gl.ARRAY_BUFFER, _quadVertexBuffer);
          gl.bufferData(gl.ARRAY_BUFFER, _vertexDataF32, gl.DYNAMIC_DRAW);
      }
      _vertexSize = numQuads * 4;
  }
  
  // Inspired from @Heishe's gotta-batch-them-all branch
  // https://github.com/Talisca/cocos2d-html5/commit/de731f16414eb9bcaa20480006897ca6576d362c
  function initQuadBuffer (numQuads) {
      var gl = cc._renderContext;
      if (_quadIndexBuffer === null) {
          // TODO do user need to release the memory ?
          _quadVertexBuffer = gl.createBuffer();
          _quadIndexBuffer = gl.createBuffer();
  
          updateQuadBuffer(numQuads);
      }
      else {
          updateQuadBuffer(numQuads);
      }
  }
  
  return {
      mat4Identity: null,
  
      childrenOrderDirty: true,
      assignedZ: 0,
      assignedZStep: 1/100,
  
      _transformNodePool: [],                              //save nodes transform dirty
      _renderCmds: [],                                     //save renderer commands
  
      _isCacheToBufferOn: false,                          //a switch that whether cache the rendererCmd to cacheToCanvasCmds
      _cacheToBufferCmds: {},                              // an array saves the renderer commands need for cache to other canvas
      _cacheInstanceIds: [],
      _currentID: 0,
      _clearColor: cc.color(),                            //background color,default BLACK
  
      init: function () {
          var gl = cc._renderContext;
          gl.disable(gl.CULL_FACE);
          gl.disable(gl.DEPTH_TEST);
  
          this.mat4Identity = new cc.math.Matrix4();
          this.mat4Identity.identity();
          initQuadBuffer(2000);
          if (cc.sys.os === cc.sys.OS_IOS) {
              _IS_IOS = true;
          }
      },
  
      getVertexSize: function () {
          return _vertexSize;
      },
  
      getRenderCmd: function (renderableObject) {
          //TODO Add renderCmd pool here
          return renderableObject._createRenderCmd();
      },
  
      _turnToCacheMode: function (renderTextureID) {
          this._isCacheToBufferOn = true;
          renderTextureID = renderTextureID || 0;
          if (!this._cacheToBufferCmds[renderTextureID]) {
              this._cacheToBufferCmds[renderTextureID] = [];
          }
          else {
              this._cacheToBufferCmds[renderTextureID].length = 0;
          }
          if (this._cacheInstanceIds.indexOf(renderTextureID) === -1) {
              this._cacheInstanceIds.push(renderTextureID);
          }
          this._currentID = renderTextureID;
      },
  
      _turnToNormalMode: function () {
          this._isCacheToBufferOn = false;
      },
  
      _removeCache: function (instanceID) {
          instanceID = instanceID || this._currentID;
          var cmds = this._cacheToBufferCmds[instanceID];
          if (cmds) {
              cmds.length = 0;
              delete this._cacheToBufferCmds[instanceID];
          }
  
          var locIDs = this._cacheInstanceIds;
          cc.arrayRemoveObject(locIDs, instanceID);
      },
  
      /**
       * drawing all renderer command to cache canvas' context
       * @param {Number} [renderTextureId]
       */
      _renderingToBuffer: function (renderTextureId) {
          renderTextureId = renderTextureId || this._currentID;
          var locCmds = this._cacheToBufferCmds[renderTextureId];
          var ctx = cc._renderContext;
          this.rendering(ctx, locCmds);
          this._removeCache(renderTextureId);
  
          var locIDs = this._cacheInstanceIds;
          if (locIDs.length === 0)
              this._isCacheToBufferOn = false;
          else
              this._currentID = locIDs[locIDs.length - 1];
      },
  
      //reset renderer's flag
      resetFlag: function () {
          if (this.childrenOrderDirty) {
              this.childrenOrderDirty = false;
          }
          this._transformNodePool.length = 0;
      },
  
      //update the transform data
      transform: function () {
          var locPool = this._transformNodePool;
          //sort the pool
          locPool.sort(this._sortNodeByLevelAsc);
          //transform node
          var i, len, cmd;
          for (i = 0, len = locPool.length; i < len; i++) {
              cmd = locPool[i];
              cmd.updateStatus();
          }
          locPool.length = 0;
      },
  
      transformDirty: function () {
          return this._transformNodePool.length > 0;
      },
  
      _sortNodeByLevelAsc: function (n1, n2) {
          return n1._curLevel - n2._curLevel;
      },
  
      pushDirtyNode: function (node) {
          //if (this._transformNodePool.indexOf(node) === -1)
          this._transformNodePool.push(node);
      },
  
      clearRenderCommands: function () {
          // Copy previous command list for late check in rendering
          this._renderCmds.length = 0;
      },
  
      clear: function () {
          var gl = cc._renderContext;
          gl.clearColor(this._clearColor.r, this._clearColor.g, this._clearColor.b, this._clearColor.a);
          gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
      },
  
      setDepthTest: function (enable){
          var gl = cc._renderContext;
          if(enable){
              gl.clearDepth(1.0);
              gl.enable(gl.DEPTH_TEST);
              gl.depthFunc(gl.LEQUAL);
          }
          else{
              gl.disable(gl.DEPTH_TEST);
          }
      },
      
      pushRenderCommand: function (cmd) {
          if(!cmd.needDraw())
              return;
          if (this._isCacheToBufferOn) {
              var currentId = this._currentID, locCmdBuffer = this._cacheToBufferCmds;
              var cmdList = locCmdBuffer[currentId];
              if (cmdList.indexOf(cmd) === -1)
                  cmdList.push(cmd);
          } else {
              if (this._renderCmds.indexOf(cmd) === -1) {
                  this._renderCmds.push(cmd);
              }
          }
      },
  
      _increaseBatchingSize: function (increment) {
          _batchingSize += increment;
      },
  
      _uploadBufferData: function (cmd) {
          if (_batchingSize >= _vertexSize) {
              this._batchRendering();
          }
  
          // Check batching
          var texture = cmd._node._texture;
          var blendSrc = cmd._node._blendFunc.src;
          var blendDst = cmd._node._blendFunc.dst;
          var shader = cmd._shaderProgram;
          if (_batchedInfo.texture !== texture ||
              _batchedInfo.blendSrc !== blendSrc ||
              _batchedInfo.blendDst !== blendDst ||
              _batchedInfo.shader !== shader) {
              // Draw batched elements
              this._batchRendering();
              // Update _batchedInfo
              _batchedInfo.texture = texture;
              _batchedInfo.blendSrc = blendSrc;
              _batchedInfo.blendDst = blendDst;
              _batchedInfo.shader = shader;
          }
  
          // Upload vertex data
          var len = cmd.uploadData(_vertexDataF32, _vertexDataUI32, _batchingSize * _sizePerVertex);
          if (len > 0) {
              _batchingSize += len;
          }
      },
  
      _batchRendering: function () {
          if (_batchingSize === 0 || !_batchedInfo.texture) {
              return;
          }
  
          var gl = cc._renderContext;
          var texture = _batchedInfo.texture;
          var shader = _batchedInfo.shader;
          var count = _batchingSize / 4;
  
          if (shader) {
              shader.use();
              shader._updateProjectionUniform();
          }
  
          cc.glBlendFunc(_batchedInfo.blendSrc, _batchedInfo.blendDst);
          cc.glBindTexture2DN(0, texture);                   // = cc.glBindTexture2D(texture);
  
          var _bufferchanged = !gl.bindBuffer(gl.ARRAY_BUFFER, _quadVertexBuffer);
          // upload the vertex data to the gl buffer
          if (_batchingSize > _vertexSize * 0.5) {
              gl.bufferData(gl.ARRAY_BUFFER, _vertexDataF32, gl.DYNAMIC_DRAW);
          }
          else {
              var view = _vertexDataF32.subarray(0, _batchingSize * _sizePerVertex);
              gl.bufferData(gl.ARRAY_BUFFER, view, gl.DYNAMIC_DRAW);
          }
  
          if (_bufferchanged) {
              gl.enableVertexAttribArray(cc.VERTEX_ATTRIB_POSITION);
              gl.enableVertexAttribArray(cc.VERTEX_ATTRIB_COLOR);
              gl.enableVertexAttribArray(cc.VERTEX_ATTRIB_TEX_COORDS);
              gl.vertexAttribPointer(cc.VERTEX_ATTRIB_POSITION, 3, gl.FLOAT, false, 24, 0);
              gl.vertexAttribPointer(cc.VERTEX_ATTRIB_COLOR, 4, gl.UNSIGNED_BYTE, true, 24, 12);
              gl.vertexAttribPointer(cc.VERTEX_ATTRIB_TEX_COORDS, 2, gl.FLOAT, false, 24, 16);
          }
  
          gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, _quadIndexBuffer);
          gl.drawElements(gl.TRIANGLES, count * 6, gl.UNSIGNED_SHORT, 0);
  
          cc.g_NumberOfDraws++;
  
          _batchingSize = 0;
      },
  
      /**
       * drawing all renderer command to context (default is cc._renderContext)
       * @param {WebGLRenderingContext} [ctx=cc._renderContext]
       */
      rendering: function (ctx, cmds) {
          var locCmds = cmds || this._renderCmds,
              i, len, cmd, next, batchCount,
              context = ctx || cc._renderContext;
  
          // Reset buffer for rendering
          context.bindBuffer(gl.ARRAY_BUFFER, null);
  
          for (i = 0, len = locCmds.length; i < len; ++i) {
              cmd = locCmds[i];
  
              if (cmd.uploadData) {
                  this._uploadBufferData(cmd);
              }
              else {
                  if (_batchingSize > 0) {
                      this._batchRendering();
                  }
                  cmd.rendering(context);
              }
          }
          this._batchRendering();
          _batchedInfo.texture = null;
      }
  };
  })();