学习opengl（起步）

#ifndef GLUT_DISABLE_ATEXIT_HACK  
#define GLUT_DISABLE_ATEXIT_HACK 
#endif  
#include <stdio.h>
#include <gl/glut.h>


void init()
{
    glClearColor(1.0,1.0,1.0,0.0);
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(0.0,200.0,0.0,150.0);
}

void lineSegment()
{
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1.0,0.0,0.0);
    glBegin(GL_LINES);
        glVertex2i(180,15);
        glVertex2i(10,145);
    glEnd();
    glFlush();
}

void main(int argc,char **argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(400,300);
    glutCreateWindow("第一个程序");

    init();
    glutDisplayFunc(lineSegment);
    glutMainLoop();
}