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。
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

#include < GL/glut.h >
#include < stdlib.h >

GLfloatpoint1[] = {0.25,0.25,0.0} ;
GLfloatpoint2[] = {0.75,0.25,0.0} ;
GLfloatpoint3[] = {0.75,0.75,0.0} ;
GLfloatpoint4[] = {0.25,0.75,0.0} ;
GLfloatpoint5[] = {0.3,0.45,0.0} ;
GLfloatpoint6[] = {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("HelloOpenGL");//创建窗口,标题为"HelloOpenGL"
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();
return0;
}