glViewport用例

说明

,,,, glViewport决定了将OpengGL渲染的图形,显示在屏幕的什么位置,第一和第二参数决定开始渲染的位置,后两个参数分别为宽和高

代码

# include & lt; gl/glut.h>

空白显示()

{

,glClear (GL_COLOR_BUFFER_BIT);

,glColor3f (1.0, 0.0, 0.0);

,//画分割线,分成四个视见区

,glViewport (0, 0, 400, 400);

,glBegin (GL_LINES);

,glVertex2f (-1.0, 0),

,glVertex2f (1.0, 0),

,glVertex2f (0.0, -1.0);

,glVertex2f (0.0, 1.0);

,glEnd ();

,//定义在左下角的区域

,glColor3f (0.0, 1.0, 0.0);

,glViewport (0, 0, 200, 200);

,glBegin (GL_POLYGON);

,glVertex2f (-0.5, -0.5);

,glVertex2f (-0.5, 0.5);

,glVertex2f (0.5, 0.5);

,glVertex2f (0.5, -0.5);

,glEnd ();

,//定义在右上角的区域

,glColor3f (0.0, 0.0, 1.0);

,glViewport(200、200、200、200);//注意,后面这两个参数是高度和宽度,而不是坐标

,glBegin (GL_POLYGON);

,glVertex2f (-0.5, -0.5);

,glVertex2f (-0.5, 0.5);

,glVertex2f (0.5, 0.5);

,glVertex2f (0.5, -0.5);

,glEnd ();

,//定义在左上角的区域

,glColor3f (1.0, 0.0, 0.0);

,glViewport(0, 200, 200, 200);//注意,后面这两个参数是高度和宽度,而不是坐标

,glBegin (GL_POLYGON);

,glVertex2f (-0.5, -0.5);

,glVertex2f (-0.5, 0.5);

,glVertex2f (0.5, 0.5);

,glVertex2f (0.5, -0.5);

,glEnd ();

,//定义在右下角

,glColor3f (1.0, 1.0, 1.0);

,glViewport(200, 0, 200, 200);//注意,后面这两个参数是高度和宽度,而不是坐标

,glBegin (GL_POLYGON);

,glVertex2f (-0.5, -0.5);

,glVertex2f (-0.5, 0.5);

,glVertex2f (0.5, 0.5);

,glVertex2f (0.5, -0.5);

,glEnd ();

,glFlush ();}

空白init ()

{

,glClearColor (0.0, 0.0, 0.0, 0.0);

,glColor3f (1.0, 1.0, 1.0);

,glMatrixMode (GL_PROJECTION);

,glLoadIdentity ();

,//定义剪裁面

,//gluOrtho2D (-1.0, 1.0, -1.0, 1.0);}

int主要(int命令行参数个数,char * * argv)

{

,glutInit(和命令行参数个数,argv);

,glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);

,glutInitWindowPosition (100、100);

,glutInitWindowSize (400、400);

,glutCreateWindow (“glViewport”);

,glutDisplayFunc(显示),

,init ();

,glutMainLoop ();}

glViewport用例