Opengl ES IBO(索引缓冲区) VBO(顶点缓冲区)创建一个立方体

1 创建

            //立方体顶点属性
             Vertex cubeVerticesIndexed[] =
            {
                { -1.0f,-1.0f, 1.0f, 0.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 0
                {  1.0f,-1.0f, 1.0f, 0.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 1
                {  1.0f, 1.0f, 1.0f, 1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 2
                { -1.0f, 1.0f, 1.0f, 1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 3
                { -1.0f,-1.0f,-1.0f, 0.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 4
                { -1.0f, 1.0f,-1.0f, 1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 5
                {  1.0f, 1.0f,-1.0f, 1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 6
                {  1.0f,-1.0f,-1.0f, 1.0f,1.0f,     1.0f, 1.0f, 1.0f,1.0f  }, // 7
            };
            //索引点
            GLubyte indexBuf[] =
            {
                0, 1, 2, 0, 2, 3, // Quad 0
                4, 5, 6, 4, 6, 7, // Quad 1
                5, 3, 2, 5, 2, 6, // Quad 2
                4, 7, 1, 4, 1, 0, // Quad 3
                7, 6, 2, 7, 2, 1, // Quad 4
                4, 0, 3, 4, 3, 5  // Quad 5
            };
            unsigned            _vbo;
            //创建顶点缓冲区
            glGenBuffers(1,&_vbo);
            //制定vbo类型
            glBindBuffer(GL_ARRAY_BUFFER,_vbo);
            //给vbo赋值glBufferData(GL_ARRAY_BUFFER,sizeof(cubeVerticesIndexed),cubeVerticesIndexed,GL_STATIC_DRAW);
            //恢复初始状态
            glBindBuffer(GL_ARRAY_BUFFER,0);
            //创建ibo
            glGenBuffers(1,&_indexbo);
            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,_indexbo);
                        glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indexBuf),indexBuf,GL_STATIC_DRAW);
            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);

2 渲染：

//矩阵变换
 CELL::matrix4   MVP     =   matProj * matView * matRot;

//给一个纹理
                glBindTexture(GL_TEXTURE_2D,_textureId);
                glBindBuffer(GL_ARRAY_BUFFER,_vbo);
                glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,_indexbo);

                glUniformMatrix4fv(_shader._MVP, 1, false, MVP.data());
                glVertexAttribPointer(_shader._positionAttr,3,  GL_FLOAT,   false,  sizeof(Vertex),(void*)0);
                glVertexAttribPointer(_shader._uvAttr,2,        GL_FLOAT,   false,  sizeof(Vertex),(void*)12);
                glVertexAttribPointer(_shader._colorAttr,4,     GL_FLOAT,   false,  sizeof(Vertex),(void*)20);

                glDrawElements(GL_TRIANGLES,36,GL_UNSIGNED_BYTE,0);
                glBindBuffer(GL_ARRAY_BUFFER,0);
                glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);