OpenGL的glViewPort窗口设置函数实现分屏

之前实现过全景图片查看（OpenGL的几何变换3之内观察全景图），那么我们需要进行分屏该如何实现呢？如下图：

没错就是以前提过的glViewPort函数，废话不多说了，我直接上代码：

 //从这里开始进行所有的绘制
 void drawCube(void)
 {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);    //清除屏幕和深度缓存
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();    //重置当前的模型观察矩阵

     glPushMatrix();
     {
         gluLookAt(, , -, , , , , , );
         glTranslatef(0.0f, 0.0f, -5.0f);    //移入屏幕 5 个单位
         glRotatef(xangle_Textures, 1.0f, 0.0f, 0.0f);    //绕X轴旋转
         glRotatef(yangle_Textures, 0.0f, 1.0f, 0.0f);    //绕Y轴旋转
         glRotatef(zangle_Textures, 0.0f, 0.0f, 1.0f);    //绕Z轴旋转
         for (int i = ; i < ; i++) {
             glViewport(i * w_Textures, , w_Textures, h_Textures);
             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //前面：纹理顺时针，立方体逆时针
                 glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    //纹理和四边形的右下
             }glEnd();

             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //后面：纹理顺时针，立方体逆时针
                 glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    //纹理和四边形的右下
             }glEnd();

             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //顶面：纹理顺时针，立方体逆时针
                 glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    //纹理和四边形的右下
             }glEnd();

             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //底面：纹理顺时针，立方体逆时针
                 glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    //纹理和四边形的右下
             }glEnd();

             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //右面：纹理顺时针，立方体逆时针
                 glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    //纹理和四边形的右下
             }glEnd();

             glBindTexture(GL_TEXTURE_2D, texturesArr[]);    //选择纹理
             glBegin(GL_QUADS); {
                 //左面：纹理顺时针，立方体逆时针

                 glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    //纹理和四边形的左下
                 glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    //纹理和四边形的左上
                 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    //纹理和四边形的右上
                 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    //纹理和四边形的右下
             }glEnd();
         }
     }glPopMatrix();
     glFlush();
 }