逐点判断方法.c

一个图形学和数据结构作业文档和实现代吗

/**********************************************************************
 This is a program of filling a Polygon Area Point by Point
	                   CopyRights 2002 By LiLi.
**********************************************************************/
#include "time.h"
#include "graphics.h"
#define MAX 100
typedef enum {FALSE,TRUE}Boolean;
typedef struct { int x;
		 int y;
	       }Point;
typedef struct { int PolygonNum;
		 Point verteces[MAX];
	       }Polygon;
clock_t starttime,finishtime;
double timeused;
void FillPolygonPbyP(Polygon *P,int polygonColor,int backgroundColor)
{int x,y;
 int i;
 int gdriver=DETECT,gmode;
 int Height,Width;
 Boolean IsInside(Polygon *,int,int);
 initgraph(&gdriver,&gmode,"");
 Height=getmaxy();
 Width=getmaxx();
 starttime=clock();        /* start record time */
 for(y=0;y<=Height;y++)    /* Judge Point By Point */
   for(x=0;x<=Width;x++)
    if(IsInside(P,x,y))
	putpixel(x,Height-y,polygonColor);
    else
	putpixel(x,Height-y,backgroundColor);
 finishtime=clock();      /* stop record time */
 /* getch();  */
 closegraph();
}

Boolean IsInside(Polygon *P,int x,int y)
{int i;
 int sum=0;    /* sum is used to record the Code of each edge */
 int Coding(float,float,float,float,int,int);
 Boolean IsInEdge(int,int,int,int,int,int);
 /* Deal with the Points On the Polygon */
 for(i=0;i<P->PolygonNum;i++)
   if(IsInEdge(P->verteces[i].x,P->verteces[i].y,P->verteces[i+1].x,
      P->verteces[i+1].y,x,y))
      return TRUE;
 for(i=1;i<=P->PolygonNum;i++)
  sum+=Coding(P->verteces[i-1].x,P->verteces[i-1].y,
	 P->verteces[i].x,P->verteces[i].y,x,y);
 if(sum==0)
    return FALSE;
 else
    return TRUE;
}

Boolean IsInEdge(int x0,int y0,int x1,int y1,int x,int y)
{
 if(x0==x1&&x0==x)            /* when it's a vertical line */
  {if((y>=y0&&y<=y1)||(y<=y0&&y>=y1))return TRUE;}
 else if((y-y0)*(x1-x0)==(x-x0)*(y1-y0))
  {if((x>=x0&&x<=x1)||(x<=x0&&x>=x1))return TRUE;}
 return FALSE;
}

int Coding(float x0,float y0,float x1,float y1,int x,int y)
{int code0, code1;
 float MidPointx,MidPointy;
 if(x0>x&&y0>=y)
     code0=0;
 else if(x0<=x&&y0>y)
     code0=1;
 else if(x0<x&&y0<=y)
     code0=2;
 else
     code0=3;

 if(x1>x&&y1>=y)
     code1=0;
 else if(x1<=x&&y1>y)
     code1=1;
 else if(x1<x&&y1<=y)
     code1=2;
 else
     code1=3;

 if(code1-code0==3)
     return -1;
 else if(code1-code0==-3)
     return 1;
 else if(code1-code0==1)
     return 1;
 else if(code1-code0==-1)
     return -1;
 else if(code1==code0)
     return 0;
 else
     {MidPointx=(x0+x1)/2;
      MidPointy=(y0+y1)/2;
      return Coding(x0,y0,MidPointx,MidPointy,x,y)+
	  Coding(MidPointx,MidPointy,x1,y1,x,y);
     }
}
main()
{int i;
 int Color,bgColor;
 Polygon *P;
 printf("Please Enter The Vertex Number Of the Polygon.\n");
 scanf("%d",&P->PolygonNum);
 for(i=0;i<P->PolygonNum;i++)
  {printf("The x Coordinate Of the %d Vertex.\n",i);
   scanf("%d",&P->verteces[i].x);
   printf("The y Coordinate Of the %d Vertex.\n",i);
   scanf("%d",&P->verteces[i].y);
  }
 printf("The Color Of the Plygon Area:\n");
 scanf("%d",&Color);
 printf("The BackGroundColor Of the Screen.\n");
 scanf("%d",&bgColor);
 P->verteces[i].x=P->verteces[0].x;
 P->verteces[i].y=P->verteces[0].y;
 FillPolygonPbyP(P,Color,bgColor);
 timeused=(double)(finishtime-starttime)/CLK_TCK;
 printf("The Program Used %f seconds.\n",timeused);
 getch();