要求：绘制钻石图案。将一圆周进行n等分，然后将所有的等分用直线连接，构成图案。
n=8
q =2*p/n
X=2*r*cos(q)
Y=r*sin(q)
#include <GL/glut.h> #include <math.h> #include <stdlib.h> #include <stdio.h> #define pi 3.14159265 int n=8; int R=200,CX=250,CY=250; int *point; void initGraph(void); void drawCircle(int cx, int cy, int r); void display(void); void drawLine(int x1, int y1, int x2, int y2); void main(int argc, char **argv){ float w,wi; glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB) ; glutInitWindowSize(500,500); glutCreateWindow("n阶钻石图案"); initGraph(); point=(int*)malloc(sizeof(int)*n*2);//申请存储空间 w=2*pi/n; wi=w/2; for(int i=0;i<2*n;i+=2){ point[i]=(int)(CX+R*cos(wi)); point[i+1]=(int)(CY+R*sin(wi)); wi+=w; } glutDisplayFunc(display); glutMainLoop(); if(point!=NULL)free(point);//释放存储空间 } void initGraph (void){ glClearColor(0.0,0.0,0.0,0.0); gluOrtho2D(0.0,500.0,0.0,500.0);//窗口坐标左下角(0,0), 右上角(500,500) } void display(void){ glClear(GL_COLOR_BUFFER_BIT) ; glColor3f(5.0, 3.0, 4.0) ; for(int i=0;i<2*n-2;i+=2){ for(int j=i+2;j<2*n;j+=2){ drawLine(point[i],point[i+1],point[j],point[j+1]); } } } void drawLine(int x1, int y1, int x2, int y2) { glBegin(GL_LINES); glVertex2d(x1, y1); glVertex2d(x2, y2); glEnd(); glFlush() ; }
