【openGL】画直线

 1 #include "stdafx.h"
 2 #include <GL/glut.h>
 3 #include <stdlib.h>
 4 #include <math.h>
 5 #include <stdio.h>
 6
 7 using namespace std;
 8
 9
10 void myDisplay(void){
11     glClear(GL_COLOR_BUFFER_BIT);
12     //glRectf(-0.5f, -0.5f, 0.5f, 0.5f);
13
14     glBegin(GL_LINES);
15     glVertex2f(-0.5f, -0.5f);        //直线起始坐标
16     glVertex2f(0.5f, 0.5f);         //直线结束坐标
17     glEnd();
18
19     glBegin(GL_LINES);
20     glVertex2f(-0.5f, 0.5f);
21     glVertex2f(0.5f, -0.5f);
22     glEnd();
23
24     glBegin(GL_LINES);
25     glVertex2f(-0.5f, 0.5f);
26     glVertex2f(-0.5f, -0.5f);
27     glEnd();
28
29     glBegin(GL_LINES);
30     glVertex2f(0.5f, 0.5f);
31     glVertex2f(0.5f, -0.5f);
32     glEnd();
33
34     glBegin(GL_LINES);
35     glVertex2f(-0.5f, 0.5f);
36     glVertex2f(0.5f, 0.5f);
37     glEnd();
38
39     glBegin(GL_LINES);
40     glVertex2f(-0.5f, -0.5f);
41     glVertex2f(-0.5f, 0.5f);
42     glEnd();
43
44     glBegin(GL_LINES);
45     glVertex2f(0, 0.5f);
46     glVertex2f(0, -0.5f);
47     glEnd();
48
49     glBegin(GL_LINES);
50     glVertex2f(-0.5f, -0.5f);
51     glVertex2f(0.5, -0.5f);
52     glEnd();
53
54     glBegin(GL_LINES);
55     glVertex2f(-0.5f, 0);
56     glVertex2f(0.5, 0);
57     glEnd();
58
59     glFlush();
60 }
61 int main(int argc, char *argv[]) {
62     glutInit(&argc, argv);
63     glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
64     glutInitWindowPosition(100, 100);
65     glutInitWindowSize(500, 500);
66     glutCreateWindow("第一个 OpenGL 程序");
67     glutDisplayFunc(&myDisplay);
68     glutMainLoop();
69     return 0;
70 }

运行图像：