OpenGL入门笔记（十）

要使用GLUT库，要将glut32.lib放到VC98/Lib下，将glut.h放到VC98/Include/GL下，并在程序中包含进glut.h。



#include <GL/glut.h>


#include <stdlib.h>






GLfloat point1[] =

{0.25,0.25,0.0};




GLfloat point2[] =

{0.75,0.25,0.0};




GLfloat point3[] =

{0.75,0.75,0.0};




GLfloat point4[] =

{0.25,0.75,0.0};




GLfloat point5[] =

{0.3,0.45,0.0};




GLfloat point6[] =

{0.5f,0.5f,0.0f};




void init(void)






{//初始化OpenGL参数


glClearColor(0.0,0.0,0.0,0.0);//设置清空颜色


glShadeModel(GL_FLAT);//设置阴影模式


glLineWidth(2.0);


glLineStipple(1,0xCCFC);


glEnable(GL_LINE_STIPPLE);


}




void DrawPoint(void)






{//画点


glColor3f(0.0f,0.0f,1.0f);


glPointSize(10.0);


glBegin(GL_POINTS);


glVertex3fv(point6);


glEnd();


}




void DrawPolyGon(void)






{//画正方形




glColor3f(0.3f,0.2f,0.0f);//设置绘制颜色




glBegin(GL_POLYGON);//绘制正方形


glVertex3fv(point1);


glVertex3fv(point2);


glVertex3fv(point3);


glVertex3fv(point4);


glEnd();


}




void DrawLines(void)






{//画直线


glColor3f(0.0f,1.0f,0.0f);






glBegin(GL_LINES);


glVertex3fv(point1);


glVertex3fv(point3);


glVertex3fv(point2);


glVertex3fv(point4);


glEnd();


}




void DrawTriangle(void)






{//画三角形


glColor3f(0.0f,1.0f,0.0f);




glBegin(GL_TRIANGLES);


glVertex3fv(point1);


glVertex3fv(point5);


glVertex3fv(point6);


glEnd();


}




void DrawLinesStrip(void)






{


glColor3f(1.0f,1.0f,1.0f);






glBegin(GL_LINE_STRIP);


glVertex3fv(point1);


glVertex3fv(point3);


glVertex3fv(point5);


glVertex3fv(point2);


glVertex3fv(point4);




glEnd();


}




void DrawLineLoop(void)






{


glColor3f(1.0f,1.0f,1.0f);




glBegin(GL_LINE_LOOP);


glVertex3fv(point1);


glVertex3fv(point3);


glVertex3fv(point5);


glVertex3fv(point2);


glVertex3fv(point4);




glEnd();


}




void display(void)






{//绘制函数


glClear(GL_COLOR_BUFFER_BIT);//清空缓存


DrawPolyGon();


DrawPoint();


DrawTriangle();


DrawLines();


DrawLinesStrip();


DrawLineLoop();


glutSwapBuffers();//交换缓存


}




void reshape(int w,int h)






{//重画函数，初次绘制，移动窗口或改变窗口大小时调用


glViewport(0,0,(GLsizei)w,(GLsizei)h);//视口变换


glMatrixMode(GL_PROJECTION);


glLoadIdentity();


// glOrtho(0.0,1.0,0.0,1.0,-1.0,1.0);//投影变换


gluOrtho2D(0.0f,1.0f,0.0f,1.0f);


glMatrixMode(GL_MODELVIEW);//开始模型视图变换


glLoadIdentity();


}




int main(int argc,char**argv)






{


glutInit(&argc,argv);


glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);//设置显示模式为"双缓冲，RGB"


glutInitWindowPosition(100,100);//窗口左上角在(100,100);


glutInitWindowSize(500,400);//窗口大小为宽500,高400


glutCreateWindow("Hello OpenGL");//创建窗口,标题为"Hello OpenGL"


init();//初始化OpenGL参数


glutDisplayFunc(display);//注册显示回调函数


glutReshapeFunc(reshape);//注册重画函数


glutMainLoop();


return 0;


}