Opengl缓冲区

 {
     1:顶点缓冲区 GL_ARRAY_BUFFER
     2:索引缓冲区 GL_ELEMENT_ARRAY_BUFFER
     3:帧缓冲区 GL_FRAMEBUFFER/GL_RENDERBUFFER
     4:封装
 }

 {1:顶点缓冲区 GL_ARRAY_BUFFER

     OpenGL-ES 中 Vertex Arrays/Buffer Objects 在这个阶段发生

     struct VX{
         float x, y, z;
         float u,v;
         float r, g, b,a;
     };

     float zOff=-2.1f;
     VX vertexs[] ={
         { -1.0f,-1.0f, zOff,    0.0f,0.0f,  1.0f,1.0f, 1.0f,1.0f },
         {  1.0f,-1.0f, zOff,    1.0f,0.0f,  1.0f,1.0f, 1.0f,1.0f },
         {  1.0f, 1.0f, zOff,    1.0f,1.0f,  1.0f,1.0f, 1.0f,1.0f },

         { -1.0f,-1.0f, zOff,    0.0f,0.0f,  1.0f,1.0f, 1.0f,1.0f },
         {  1.0f, 1.0f, zOff,    1.0f,1.0f,  1.0f,1.0f, 1.0f,1.0f },
         { -1.0f, 1.0f, zOff,    0.0f,1.0f,  1.0f,1.0f, 1.0f,1.0f },
     };

     unsigned vbId; //数据id

     {创建数据
         glGenBuffers(1,&vbId);
         glBindBuffer(GL_ARRAY_BUFFER,vbId); //绑定/取消缓冲区
         glBufferData(GL_ARRAY_BUFFER,sizeof(vertexs),vertexs,GL_STATIC_DRAW);//设置缓冲区数据
         glBindBuffer(GL_ARRAY_BUFFER,0);//绑定/取消缓冲区
     }

     {使用数据
         glBindBuffer(GL_ARRAY_BUFFER,vbId);//绑定/取消缓冲区
         glVertexAttribPointer(shader._position,3,  GL_FLOAT,   false,  sizeof(VX),(void*)0);
         glVertexAttribPointer(shader._tpos,    2,  GL_FLOAT,   false,  sizeof(VX),(void*)(3*sizeof(float)));
         glVertexAttribPointer(shader._color,   4,  GL_FLOAT,   false,  sizeof(VX),(void*)(3*sizeof(float)+2*sizeof(float)));
         glDrawArrays(GL_TRIANGLES,0,6);//三角形 (三个点画一个三角形)
         glBindBuffer(GL_ARRAY_BUFFER,0);//绑定/取消缓冲区 注意:使用完就制空，OpenGL-ES是状态机
     }

     切记:缓冲数据在什么地方用在什么地方制空，不指空的话，下面的数据全是这个缓冲数据

     注意:
         glBufferData(,size,,) size->sizeof(vertexs)是数据大小不是偏移量大小
         glVertexAttribPointer (,,,,stride,);stride->sizeof(VX)是偏移量大小不是数据大小

 }

 {2:索引缓冲区 GL_ELEMENT_ARRAY_BUFFER
     OpenGL-ES 中 Vertex Arrays/Buffer Objects 在这个阶段发生

     unsigned ibId; //数据id
     {创建数据
         glGenBuffers(1,&ibId);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,ibId); //绑定/取消缓冲区
         glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(vertexs),vertexs,GL_STATIC_DRAW);//设置缓冲区数据
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0); //绑定/取消缓冲区
     }

     {使用数据
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,ibId);//绑定/取消缓冲区
         glDrawElements(绘制模式,绘制数据大小,数据类型,);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);//绑定/取消缓冲区 注意:使用完就制空，OpenGL-ES是状态机
     }

     {code
         struct Vertex {
             float x, y, z;
             float u,v;
             float r, g, b,a;
         };
         Vertex positionData[] = {
             -1.0f, 1.0f,-1.0f,      0.0f,0.0f,     1.0f, 1.0f, 1.0f,1.0f, //  上左后
             -1.0f, 1.0f, 1.0f,      0.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f, //  上左前
             1.0f, 1.0f,-1.0f,       1.0f,0.0f,     1.0f, 1.0f, 1.0f,1.0f, //  上右后
             1.0f, 1.0f, 1.0f,       1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f, //  上右前
             -1.0f,-1.0f,-1.0f,      0.0f,0.0f,     1.0f, 1.0f, 1.0f,1.0f, //  下左后
             -1.0f,-1.0f, 1.0f,      0.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f, //  下左前
             1.0f,-1.0f,-1.0f,       1.0f,0.0f,     1.0f, 1.0f, 1.0f,1.0f, //  下右后
             1.0f,-1.0f, 1.0f,       1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  //  下右前
         };
         byte indexData[]={
             0,1,2,2,3,1,  //上
             0,4,5,5,2,0,  //左
             0,4,6,6,2,0,  //后
             2,7,6,6,2,3,  //右
             1,5,7,7,2,1,  //前
             4,5,6,6,7,4,  //下
         };


         unsigned  vbId;//顶点缓冲区 id
         unsigned  ibId;//索引缓冲区 id

         //顶点缓冲区 id
         glGenBuffers(1,&vbId);
         glBindBuffer(GL_ARRAY_BUFFER,vbId);
         glBufferData(GL_ARRAY_BUFFER,sizeof(positionData),positionData,GL_STATIC_DRAW);
         glBindBuffer(GL_ARRAY_BUFFER,0);

         //索引缓冲区 id
         glGenBuffers(1,&ibId);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,ibId);
         glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indexData),indexData,GL_STATIC_DRAW);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);

         实例1
         glBindBuffer(GL_ARRAY_BUFFER,vbId);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,ibId);
         ...
         glVertexAttribPointer(shader._position,3,  GL_FLOAT,   false,  sizeof(Vertex),(void*)0);
         glVertexAttribPointer(shader._tpos,    2,  GL_FLOAT,   false,  sizeof(Vertex),(void*)(3*sizeof(float)));
         glVertexAttribPointer(shader._color,   4,  GL_FLOAT,   false,  sizeof(Vertex),(void*)(3*sizeof(float)+2*sizeof(float)));

         glDrawElements(GL_TRIANGLES,sizeof(indexData)/sizeof(indexData[0]),GL_UNSIGNED_BYTE,0);

         glBindBuffer(GL_ARRAY_BUFFER,0);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);

         实例2
         ...
         glVertexAttribPointer(shader._position,3,  GL_FLOAT,   false,  sizeof(Vertex),(void*)0);
         glVertexAttribPointer(shader._tpos,    2,  GL_FLOAT,   false,  sizeof(Vertex),(void*)(3*sizeof(float)));
         glVertexAttribPointer(shader._color,   4,  GL_FLOAT,   false,  sizeof(Vertex),(void*)(3*sizeof(float)+2*sizeof(float)));

         glDrawElements(GL_TRIANGLES,sizeof(indexData)/sizeof(indexData[0]),GL_UNSIGNED_BYTE,indexData);

         glBindBuffer(GL_ARRAY_BUFFER,0);

     }

 }

 {3:帧缓冲区 GL_FRAMEBUFFER/GL_RENDERBUFFER
     OpenGL-ES 中 Framebuffer 在这个阶段发生

     {
         1:创建一张帧缓冲大小
         2:把要画的东西画的一张纹理上(帧缓冲和纹理id绑定)
         3:渲染这种纹理
     }

     {code

         struct FBO{
             unsigned fb;//帧缓冲
             unsigned rb;//渲染缓冲
         };

         FBO createFBO(int width,int height){
             FBO frb;
             glGenFramebuffers(1,&frb.fb);//生成帧缓冲的索引
             glBindFramebuffer(GL_FRAMEBUFFER,frb.fb);//绑定帧缓冲

             glGenRenderbuffers(1,&frb.rb);//生成渲染缓冲的索引
             glBindRenderbuffer(GL_RENDERBUFFER,frb.rb);//绑定渲染缓冲

             /** 绘制渲染缓冲区的存储大小
              * @param  target  类型(GL_RENDERBUFFER ...)
              * @param  internalformat 存储数据格式（GL_DEPTH_COMPONENT16 深度信息）
              * @param  width 存储的宽
              * @param  height 存储的高
              */
             glRenderbufferStorage(GL_RENDERBUFFER,GL_DEPTH_COMPONENT16,width,height);

             glBindRenderbuffer(GL_RENDERBUFFER,0);

             /** 帧缓冲区与渲染缓冲区绑定
              * @param  target  帧缓冲区类型(GL_FRAMEBUFFER 帧缓冲区)
              * @param  attachment  关联的类型(GL_DEPTH_ATTACHMENT 深度)
              * @param  renderbuffertarget  渲染缓冲区类型(GL_RENDERBUFFER 渲染缓冲区)
              * @param  renderbuffer  渲染缓冲区id
              */
             glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_DEPTH_ATTACHMENT,GL_RENDERBUFFER,frb.rb);

             glBindFramebuffer(GL_FRAMEBUFFER,0);

             return frb;
         }

         void beginFBO(unsigned fboId,uniform textureId){
             glBindFramebuffer(GL_FRAMEBUFFER,fboId);
             /** 帧缓冲区数据渲染到纹理上
              * @param  target 帧缓冲类型(GL_RENDERBUFFER ...)
              * @param  attachment 缓存区类型 (GL_COLOR_ATTACHMENT0 颜色缓存区)
              * @param  textarget 纹理类型 (GL_TEXTURE_2D ...)
              * @param  texture 纹理id
              * @param  level 层级别(数据渲染到纹理的什么层级别上)
              */
             glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,textureId,0);
         }
         void endFBO(){
             glBindFramebuffer(GL_FRAMEBUFFER,0);
         }

 1:创建一张帧缓冲大小
         FBO  fboId;
         unsigned textureFboId;//帧缓冲数据保存到这张纹理上

         {//帧缓冲区
             fboId=createFBO(_width,_height);
             textureFboId=createTexture(_width,_height);
         }
 2:把要画的东西画的一张纹理上(帧缓冲和纹理id绑定)
         beginFBO(fboId.fb,textureFboId);
             .... //所以要添加到帧缓冲的数据
         endFBO();
 3:渲染这种纹理
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
         //设置视口的大小
         glViewport(0,0,_width,_height);
         shader.begin();

             glBindTexture(GL_TEXTURE_2D,textureFboId);
             CELL::matrix4 mat=CELL::ortho<float>(0,(float)_width,(float)_height,0,-100,100);
             glUniformMatrix4fv(shader._MVP,1,false,mat.data());

             glVertexAttribPointer(shader._position,3,GL_FLOAT,false,sizeof(Vertex),&xt[0].pos);
             glVertexAttribPointer(shader._tpos,2,GL_FLOAT,false,sizeof(Vertex),&xt[0].uvpos);
             glVertexAttribPointer(shader._color,4,GL_FLOAT,false,sizeof(Vertex),&xt[0].rgba);
             glDrawArrays(GL_TRIANGLE_STRIP,0,sizeof(xt)/sizeof(xt[0]));

         shader.end();
     }

 }

 {4:封装
     VertexBuffer 顶点缓冲区  create,begin,end
     ElementBuffer 创建索引缓冲区  create,begin,end
     FrameBefferObject 帧缓冲  create,begin,end
 }

 //DataBuffer.hpp
 #pragma once
 #include "gles2/gl2.h"


 class DataBuffer {
 public:
     virtual~DataBuffer() {};
     virtual void begin() = 0;
     virtual void end() = 0;
     virtual void destroy() = 0;//销毁
 protected:
     DataBuffer() {};
 private:

 };


 /** 顶点缓冲区
 *   struct VX{
 *       float x, y, z;
 *       float u,v;
 *       float r, g, b,a;
 *   };
 *   VX vertexs[] ={
 *       { -1.0f,-1.0f, zOff,    0.0f,0.0f,  1.0f,1.0f, 1.0f,1.0f },
 *       {  1.0f,-1.0f, zOff,    1.0f,0.0f,  1.0f,1.0f, 1.0f,1.0f }
 *   }
 *   //创建
 *   VertexBuffer vbId=VertexBuffer::create(sizeof(vertexs),vertexs,GL_STATIC_DRAW);
 *   //使用
 *   vbId.begin();
 *       ...使用过程
 *       glVertexAttribPointer(shader._position,3,  GL_FLOAT,   false,  sizeof(VX),(void*)0);
 *       glVertexAttribPointer(shader._tpos,    2,  GL_FLOAT,   false,  sizeof(VX),(void*)(3*sizeof(float)));
 *       //glVertexAttribPointer(shader._position,3,  GL_FLOAT,   false,  sizeof(VX),vertexs[0].x);
 *       //glVertexAttribPointer(shader._tpos,    2,  GL_FLOAT,   false,  sizeof(VX),vertexs[0].u);
 *   vbId.end();
 */
 class VertexBuffer :public DataBuffer {
 public:
     unsigned vbId;
 public:
     virtual~VertexBuffer() {}

     /** 创建顶点缓冲区
     * @param  dataSize 数据大小
     * @param  data     数据
     * @param  dataType
     *       GL_STREAM_DRAW   偶尔需要改动数据
     *       GL_STATIC_DRAW   不改动(静态的)数据
     *       GL_DYNAMIC_DRAW  经常改动(动态的)数据
     * @return          [description]
     */
     static VertexBuffer  create(int dataSize, void *data, int dataType = GL_STATIC_DRAW) {
         VertexBuffer vb;
         glGenBuffers(1, &vb.vbId);
         glBindBuffer(GL_ARRAY_BUFFER, vb.vbId); //绑定/取消缓冲区
         glBufferData(GL_ARRAY_BUFFER, dataSize, data, dataType);//设置缓冲区数据(更新全部数据)
         //glBufferSubData(GL_ARRAY_BUFFER, offset, size, data);//设置缓冲区数据(更新局部数据)
         glBindBuffer(GL_ARRAY_BUFFER, 0);//绑定/取消缓冲区
         return vb;
     }
     virtual void begin() {
         glBindBuffer(GL_ARRAY_BUFFER, vbId); //绑定/取消缓冲区
     }
     virtual void end() {
         glBindBuffer(GL_ARRAY_BUFFER, 0); //绑定/取消缓冲区
     }
     virtual void destroy() {
         glDeleteBuffers(1, &vbId);
     }
 public:
     VertexBuffer() {}
 };

 /** 创建索引缓冲区
 *   byte indexData[] = {
 *       0, 1, 2, 2, 3, 0,  //上
 *       0, 4, 5, 5, 1, 0,  //左
 *       0, 4, 6, 6, 3, 0,  //后
 *       2, 7, 6, 6, 3, 2,  //右
 *       1, 5, 7, 7, 2, 1,  //前
 *       4, 5, 7, 7, 6, 4,  //下
 *   };
 *
 *   //创建
 *   int drawSize = sizeof(indexData) / sizeof(indexData[0]);
 *   ElementBuffer eb= ElementBuffer::create(drawSize,sizeof(indexData),indexData,GL_STATIC_DRAW);
 *   //使用
 *   eb.begin();
 *       ...使用过程(注意 顶点说索引同时使用eb.data 就不许添了，添0就可以了)
 *       glDrawElements(GL_TRIANGLES, eb.drawSize, GL_UNSIGNED_BYTE, eb.data);
 *   eb.end();
 */
 class ElementBuffer :public DataBuffer {
 public:
     unsigned ebId;
     int drawSize;//渲染数据个数
     void *data;//数据
 public:
     virtual~ElementBuffer() {}

     /** 创建索引缓冲
     * @param  drawSize 渲染数据个数
     * @param  dataSize 数据大小
     * @param  data     数据
     * @param  dataType
     GL_STREAM_DRAW   偶尔需要改动数据
     GL_STATIC_DRAW   不改动(静态的)数据
     GL_DYNAMIC_DRAW  经常改动(动态的)数据
     * @return          [description]
     */
     static ElementBuffer  create(int drawSize, int dataSize, void *data, int dataType = GL_STATIC_DRAW) {
         ElementBuffer eb;
         eb.drawSize = drawSize;
         eb.data = data;
         glGenBuffers(1, &eb.ebId);
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, eb.ebId); //绑定/取消缓冲区
         glBufferData(GL_ELEMENT_ARRAY_BUFFER, dataSize, data, dataType);//设置缓冲区数据(更新全部数据)
         //glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, offset, size, data);//设置缓冲区数据(更新局部数据)
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); //绑定/取消缓冲区

         return eb;
     }
     virtual void begin() {
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebId); //绑定/取消缓冲区
     }
     virtual void end() {
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); //绑定/取消缓冲区
     }
     virtual void destroy() { glDeleteBuffers(1, &ebId); }
 public:
     ElementBuffer() {
         drawSize = -1;
         data = NULL;
     }

 };

 /** 帧缓冲
 *   FrameBefferObject fboId=FrameBefferObject::create(100,100);
 *   fboId.begin(textureFboId);
 *       .... //所以要添加到帧缓冲的数据
 *   fboId.end();
 *   最后画这张 textureFboId 纹理就可以了
 */
 class FrameBefferObject {
 public:
     unsigned fb;//帧缓冲
     unsigned rb;//渲染缓冲

 public:
     virtual ~FrameBefferObject() {}
     static FrameBefferObject  create(int width, int height) {
         FrameBefferObject frb;
         glGenFramebuffers(1, &frb.fb);//生成帧缓冲的索引
         glBindFramebuffer(GL_FRAMEBUFFER, frb.fb);//绑定帧缓冲

         glGenRenderbuffers(1, &frb.rb);//生成渲染缓冲的索引
         glBindRenderbuffer(GL_RENDERBUFFER, frb.rb);//绑定渲染缓冲

         /** 绘制渲染缓冲区的存储大小
         * @param  target  类型(GL_RENDERBUFFER ...)
         * @param  internalformat 存储数据格式（GL_DEPTH_COMPONENT16 深度信息）
         * @param  width 存储的宽
         * @param  height 存储的高
         */
         glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);

         glBindRenderbuffer(GL_RENDERBUFFER, 0);

         /** 帧缓冲区与渲染缓冲区绑定
         * @param  target  帧缓冲区类型(GL_FRAMEBUFFER 帧缓冲区)
         * @param  attachment  关联的类型(GL_DEPTH_ATTACHMENT 深度)
         * @param  renderbuffertarget  渲染缓冲区类型(GL_RENDERBUFFER 渲染缓冲区)
         * @param  renderbuffer  渲染缓冲区id
         */
         glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, frb.rb);

         glBindFramebuffer(GL_FRAMEBUFFER, 0);

         return frb;
     }

     virtual void begin(unsigned textureId) {
         glBindFramebuffer(GL_FRAMEBUFFER, fb);
         /** 帧缓冲区数据渲染到纹理上
         * @param  target 帧缓冲类型(GL_RENDERBUFFER ...)
         * @param  attachment 缓存区类型 (GL_COLOR_ATTACHMENT0 颜色缓存区)
         * @param  textarget 纹理类型 (GL_TEXTURE_2D ...)
         * @param  texture 纹理id
         * @param  level 层级别(数据渲染到纹理的什么层级别上)
         */
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureId, 0);
     }

     virtual void end() {
         glBindFramebuffer(GL_FRAMEBUFFER, 0);
     }
     virtual void destroy() {
         glDeleteRenderbuffers(1, &rb);
         glDeleteFramebuffers(1, &fb);
     }
 public:
     FrameBefferObject() {}

 };

源码地址

http://pan.baidu.com/s/1geVargZ   缓冲区.zip

 main.cpp
     //头文件不能都开，里面有重复定义的类或函数，不解释了自己看吧
     //#include "VertexBufferWin.hpp"
     //#include "ElementWin.hpp"
     #include "FraneBufferWin.hpp"

     //VertexBufferWin app(hInstance);//顶点缓冲区数据
     //ElementWin app(hInstance);//索引缓冲区数据
     FraneBufferWin app(hInstance);//帧缓冲