#include <GL/glut.h>
#include "math.h"
#include<iostream>
#define PI 3.1415926
#define NUMBER 8
#define RADIUS 400
using namespace std;
//===================================================================
struct Node
{
int x,y;
};
struct Edge
{
Node s,e;
}E[11];
int map[111][111];
int v[111][111];
int maxx,maxy,minx,miny;
int n;//多边形边的数量
int fmin(int x,int y)
{
if(x<y) return x;
return y;
}
int fmax(int x,int y)
{
if(x>y) return x;
return y;
}
void init()
{
int i;
printf("请输入多边形边的数量:
");
scanf("%d",&n);
printf("请按照逆时针输入多边形的各个定点:
");
for(i=1;i<=n;i++)
{
scanf("%d%d",&E[i].s.x,&E[i].s.y);
E[i-1].e.x=E[i].s.x,E[i-1].e.y=E[i].s.y;
minx=fmin(E[i].s.x,minx);
maxx=fmax(E[i].s.x,maxx);
miny=fmin(E[i].s.y,miny);
maxy=fmax(E[i].s.y,maxy);
}
E[n].e.x=E[1].s.x;E[n].e.y=E[1].s.y;
}
void cover(int x,int y)
{
int xx=x;
while(xx<maxx)
map[xx++][y]^=1;
}
void DDa(int x0,int y0,int x1,int y1)
{
if(y0<y1)
{
int t;
t=x0;
x0=x1;
x1=t;
t=y0;
y0=y1;
y1=t;
}
int dx,dy,epsl,k;
float x,y,xIncre,yIncre;
dx=x1-x0;dy=y1-y0;
x=x0;y=y0;
if(abs(dx)>abs(dy)) epsl=abs(dx);
else epsl=abs(dy);
xIncre=(float)dx/(float)epsl;
yIncre=(float)dy/(float)epsl;
for(k=0;k<=epsl;k++)
{
if(k==0)continue;
cover(int(x+0.5),int(y+0.5));
x+=xIncre;
y+=yIncre;
}
}
void solve()
{
memset(map,0,sizeof(map));
// memset(v,0,sizeof(v));
int i;
for(i=1;i<=n;i++)
DDa(E[i].s.x,E[i].s.y,E[i].e.x,E[i].e.y);
}
void myinit(void)
{
glClearColor(1.0, 1.0, 1.0, 1.0); /* white background */
glColor3f(0.0, 0.0, 1.0); /* draw in red */
glPointSize(10);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(-5, 15, -5, 15);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_COLOR_LOGIC_OP);
}
void gl(double x1,double y1,double x2,double y2)//划线函数
{
glBegin(GL_LINES);
glVertex2f(x1,y1);
glVertex2f(x2,y2);
glEnd();
}
void gP(int x,int y)//划线函数
{
glBegin(GL_POINTS);
glVertex2i(x,y);
glEnd();
}
void grow(double x,double y,double l,double fai)
{
if(fabs(l-2.9)<1.0)//
return ;
double x1=x+cos(fai)*l,y1=y+sin(fai)*l;
gl(x,y,x1,y1);//先序划线
grow(x1,y1,l*0.618*0.618,fai+PI/3.0);//分别划左右儿子
grow(x1,y1,l*0.618*0.618,fai-PI/3.0);//
grow(x1,y1,l*0.618,fai);//
}
void zuobiao(int minx,int maxx,int miny,int maxy)
{
int i;
for(i=miny;i<=maxy;i++)
gl(minx,i,maxx+3,i);
for(i=minx;i<=maxx;i++)
gl(i,miny,i,maxy+3);
}
//===================================================================
void display( void )
{
glClear(GL_COLOR_BUFFER_BIT); /*clear the window */
zuobiao(0,7,0,7);
// gP(0,0);
for(int i=maxy;i>=miny;i--)
{
for(int j=minx;j<=maxx;j++)
if(map[j][i])
gP(j,i);
}
glFlush();
}
//===================================================================
void main(int argc, char** argv)
{
/* Standard GLUT initialization */
int i,j;
init();
solve();
glutInit(&argc,argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); /* default, not needed */
glutInitWindowSize(500,500); /* 500 x 500 pixel window */
glutInitWindowPosition(0,0); /* place window top left on display */
glutCreateWindow("Diamond"); /* window title */
glutDisplayFunc(display); /* display callback invoked when window opened */
myinit(); /* set attributes */
glutMainLoop(); /* enter event loop */
}