opengl.rar_OpenGL 圆_opengl 画圆_八卦

#include <GL/glut.h> void Choice(int x,int y,int l,int w,int type) {//根据条件画圆， switch(type) { case 1://上半圆 { glVertex2f(x+l, y+w); glVertex2f(-x+l,y+w); } break; case 2://下半圆 { glVertex2f(x+l,-y+w); glVertex2f(-x+l,-y+w); } break; case 3://整个圆 { glVertex2f(x+l, y+w); glVertex2f(-x+l,y+w); glVertex2f(x+l,-y+w); glVertex2f(-x+l,-y+w); } break; default: break; } } void MyDisplay(int xx,int r,float R,float G,float B,int length,int width,int TYPE) {//根据起点坐标，半径，R，G，B,圆的位置，类型来画圆 glClear(GL_COLOR_BUFFER_BIT); glColor3f(R,G,B); int yy = r,d = 1-r;//设置半径，纵坐标，变化量 glBegin(GL_LINES); while(xx <= yy) { if(d < 0)//点在圆内 { d+= 2*xx + 3; } else //点在圆外 { d+= 2*(xx-yy) + 5; yy = yy - 1; } xx = xx + 1; //确定下一个象素的点 Choice(xx,yy,length,width,TYPE);//画圆 } while(yy >= 0) //x=y对称的八分圆 { if( d > 0) { d-= 2*yy + 3; } else { d+= 2*(xx-yy) + 5; xx = xx + 1; } yy = yy - 1; Choice(xx,yy,length,width,TYPE); } glFlush(); } void myDisplay1(void)//画整个圆的框架 { glClear(GL_COLOR_BUFFER_BIT); //刷新窗口缓冲区 glColor3f(0.0,0.0,0.0); int r = 100,xx = 0,yy = r,d = 1-r; //glBegin(GL_POINTS); while( xx <= yy) { if(d<0) { d+= 2*xx + 3; } else { d+= 2*(xx-yy) + 5; yy = yy-1; } xx = xx + 1; glBegin(GL_POINTS); Choice(xx,yy,400,300,3);//画出圆 glEnd(); } while(yy >= 0) { if(d > 0) d-= 2*yy + 3; else { d+= 2*(xx-yy) + 5; xx = xx + 1; } yy = yy - 1; glBegin(GL_POINTS); Choice(xx,yy,400,300,3);//画出x=y的对称圆 glEnd(); } glFlush(); } void init(void) { glClearColor(1.0,1.0,1.0,0.0); glMatrixMode(GL_PROJECTION); } void Reshape(GLsizei w,GLsizei h) { glViewport(0,0,w,h); glLoadIdentity(); gluOrtho2D(0.0,(GLdouble)w,0.0,(GLdouble)h); } void myDisplay(void) { MyDisplay(0,100,0.0,0.0,0.0,400,300,1);//上半个大黑圆 MyDisplay(0,50,1.0,1.0,1.0,350,300,3);// 左边的中白圆 MyDisplay(0,50,0.0,0.0,0.0,450,300,3);// 右边的中黑圆 MyDisplay(0, 5,0.0,0.0,0.0,350,300,3);// 左边的小黑圆 MyDisplay(0, 5,1.0,1.0,1.0,450,300,3);// 右边的小白圆 myDisplay1();//整个圆的框架 } int main(int argc, char **argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowPosition(100,100); glutInitWindowSize(800,600); glutCreateWindow("A Beautiful Graph"); init(); glutReshapeFunc(Reshape); glutDisplayFunc(myDisplay);//注册当前窗口的显示回调函数 glutMainLoop();//进入GLUT事件处理循环 return 0; }