【OpenGL 学习笔记03】点画多边形

1.点画多边形

//定义填充多边形的点画模式。mask为32 x 32 的位图指针，1画0不画，使用前必须启用多边形点画功能
void glPloygonStipple(const GLubyte* mask);
//绘制一个矩形
void glRectf(GLfloat x1,GLfloat y1,GLfloat x2,GLfloat y2);

2.示例

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

void display(void)
{
	GLubyte fly[] = {
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x03, 0x80, 0x01, 0xC0, 0x06, 0xC0, 0x03, 0x60, 
		0x04, 0x60, 0x06, 0x20, 0x04, 0x30, 0x0C, 0x20, 
		0x04, 0x18, 0x18, 0x20, 0x04, 0x0C, 0x30, 0x20,
		0x04, 0x06, 0x60, 0x20, 0x44, 0x03, 0xC0, 0x22, 
		0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
		0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
		0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
		0x66, 0x01, 0x80, 0x66, 0x33, 0x01, 0x80, 0xCC, 
		0x19, 0x81, 0x81, 0x98, 0x0C, 0xC1, 0x83, 0x30,
		0x07, 0xe1, 0x87, 0xe0, 0x03, 0x3f, 0xfc, 0xc0, 
		0x03, 0x31, 0x8c, 0xc0, 0x03, 0x33, 0xcc, 0xc0, 
		0x06, 0x64, 0x26, 0x60, 0x0c, 0xcc, 0x33, 0x30,
		0x18, 0xcc, 0x33, 0x18, 0x10, 0xc4, 0x23, 0x08, 
		0x10, 0x63, 0xC6, 0x08, 0x10, 0x30, 0x0c, 0x08, 
		0x10, 0x18, 0x18, 0x08, 0x10, 0x00, 0x00, 0x08};

	GLubyte halftone[] = {
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
		0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55};

	glClear (GL_COLOR_BUFFER_BIT);
	glColor3f (1.0, 1.0, 1.0);//白色

	//矩形1
	glRectf (25.0, 25.0, 125.0, 125.0);	//绘制矩形

	//矩形2
	glEnable (GL_POLYGON_STIPPLE);		//开启多边形点画功能
	glPolygonStipple (fly);				//定义点画模式填充内容
	glRectf (125.0, 25.0, 225.0, 125.0);//绘制矩形
	
	//矩形3
	glPolygonStipple (halftone);
	glRectf (225.0, 25.0, 325.0, 125.0);
	glDisable (GL_POLYGON_STIPPLE);		//关闭多边形点画功能

	glFlush ();
}

void init (void) 
{
	glClearColor (0.0, 0.0, 0.0, 0.0);
	glShadeModel (GL_FLAT);    //采用恒定着色模式，使用图元中某个顶点的颜色来渲染整个图元。  
}

void reshape (int w, int h)
{
	glViewport (0, 0, (GLsizei) w, (GLsizei) h);
	glMatrixMode (GL_PROJECTION);	 //将当前矩阵指定为投影矩阵  
	glLoadIdentity ();				 //把当前矩阵设为单位矩阵  
	gluOrtho2D (0.0, (GLdouble) w, 0.0, (GLdouble) h);
}

void keyboard(unsigned char key, int x, int y)
{
	switch (key) {
	case 27:
		exit(0);
		break;
	}
}

int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize (350, 150);
	glutCreateWindow (argv[0]);
	init ();
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutKeyboardFunc (keyboard);
	glutMainLoop();
	return 0;  
}

3.效果图