/* WIN-TC BGI 圖形編程模板 */

#include "Conio.h"
#include "graphics.h"
#define closegr closegraph
#include "math.h"
#define pie 3.1415926
void initgr(void) /* BGI初始化 */
{
  int gd = DETECT, gm = 0; /* 和gd = VGA,gm = VGAHI是同樣效果 */
  registerbgidriver(EGAVGA_driver);/* 注冊BGI驅動后可以不需要.BGI文件的支持運行 */
  initgraph(&gd, &gm, "");
}


 void CirclePoints(int x,int y,int t,int s,int color)
{
  putpixel(t+x,s+y,color);
  putpixel(s+y,t+x,color);
  putpixel(s-y,t+x,color);
  putpixel(t-x,s+y,color);
  putpixel(s+y,t-x,color);
  putpixel(t+x,s-y,color);
  putpixel(t-x,s-y,color);
  putpixel(s-y,t-x,color);
}
  void EllipsePoints(int x,int y,int t,int s,int color)
{
  putpixel(t+x,s+y,color);
  putpixel(t-x,s+y,color);
  putpixel(t+x,s-y,color);
  putpixel(t-x,s-y,color);

}


/*-----------------------------開平方法生成圓-----------------------------*/
void sqrtCircle(int radius,int color)
{
  float x,y;
  x=0;y=radius;
  CirclePoints(x,y,100,100,color);
  while(y>=x)
   {
     x++;
     y=sqrt(radius*radius-x*x);
     CirclePoints((int)(x+0.5),(int)(y+0.5),100,100,color);
   }
   outtextxy(50,170,"sqrtCircle");
}

/*----------------------------參數法生成圓---------------------------------*/
void funCircle(int radius,int color)
{
  float x,y,afla;
  x=radius;y=0;afla=0;
  CirclePoints(x,y,200,200,color);
  while (afla<=pie/4)
  {
    afla+=pie/400;
    x=radius*cos(afla);
    y=radius*sin(afla);
    CirclePoints((int)(x+0.5),(int)(y+0.5),200,200,color);
     outtextxy(100,250,"funCircle");
  }
}

/*----------------------------Bresenham算法生成圓-----------------------------*/
BresenhamCircle(int R,int color)
{
  int x,y,dD,dHD,dDV,next;
  x=0;y=R;dD=2*(1-R);
  while(y>=0)
  {
    CirclePoints(x,y,300,300,color);
    if(dD<0)
    {
      dHD=2*(dD+y)-1;
      if(dHD<=0) next=0;
      else next=1;
    }
    else if(dD>0)
    {
      dDV=2*(dD-x)-1;
      if(dDV<=0) next=1;
      else next=2;
    }
    else next=1;
    switch(next)
    {
     case 0:x++;
            dD+=2*x+1;
            break;
     case 1:x++;
            y--;
            dD+=2*(x-y+1);
            break;
     case 2:y--;
            dD+=-2*y+1;
            break;
    } /*switch*/
  }  /*while*/
  outtextxy(150,350,"BresenhamCircle");
}

/*----------------------------中點算法生成圓--------------------------------*/
void MidPointCircle(int radius,int color)
{
  int x,y,d,deltaE,deltaSE;
  x=0;
  y=radius;
  d=5-4*radius;
  deltaE=12;
  deltaSE=20-8*radius;
  CirclePoints(x,y,400,400,color);
  while(y>x)
  {
    if(d<=0)
      {d+=deltaE;
        deltaSE+=8;}
     else
      {
        d+=deltaSE;
        deltaSE+=16;
        y--;
      }
      deltaE+=8;
      x++;
      CirclePoints(x,y,400,400,color);
  }
  outtextxy(250,450,"MidPointCircle");
}

/*---------------------------開平方法生成橢圓---------------------------------*/
 void sqrtEllipse(int a,int b,int color)
{
 float x,y;
   x=0;y=b;
   EllipsePoints(x,y,300,100,color);
   while(x<a)
   {
     x++;
     y=sqrt(b*b-(x*x*b*b)/(a*a));
     EllipsePoints((int)(x+0.5),(int)(y+0.5),300,100,color);

   }
   outtextxy(350,100,"sqrtEllipse");
}
/*---------------------------參數法生成橢圓-----------------------------------*/
void funEllipse(int a,int b,int color)
{
  float x,y,afla;
  x=a;y=0;afla=0;
  EllipsePoints(x,y,400,200,color);
  while(afla<=pie/2)
  {
    afla+=pie/400;
    x=a*cos(afla);
    y=b*sin(afla);
     EllipsePoints((int)(x+0.5),(int)(y+0.5),400,200,color);
  }
  outtextxy(450,200,"funEllipse");
}
/*---------------------------中點算法生成橢圓---------------------------------*/
 void MidPointEllipse(double a,double b,int color)
  {
    double x,y,d,xP,yP,squarea,squareb;
    squarea=a*a;
    squareb=b*b;
    xP=(int)(0.5+(double)squarea/sqrt((double)(squarea+squareb)));
    yP=(int)(0.5+(double)squareb/sqrt((double)(squarea+squareb)));
    x=0;
    y=b;
    d=4*(squareb-squarea*b)+squarea;
    EllipsePoints(x,y,500,300,color);
    while(x<=xP)
    {
      if(d<=0)  d+=4*squareb*(2*x+3);
      else
        {d+=4*squareb*(2*x+3)-8*squarea*(y-1);
          y--;}
      x++;
      EllipsePoints(x,y,500,300,color);
     }
    x=a;
    y=0;
    d=4*(squarea-a*squareb)+squareb;
    EllipsePoints(x,y,500,300,color) ;
    while(y<yP)
     {
       if(d<=0)  d+=4*squarea*(2*y+3);
       else
         {
           d+=4*squarea*(2*y+3)-8*squareb*(x-1);
            x--;
         }
         y++;
         EllipsePoints(x,y,500,300,color);

     }
     outtextxy(480,380,"MidPointsEllipse");
  }

int main(void)
{
  initgr(); /* BGI初始化 */

  /*****此部分添加你自己的代碼，例如
  line(25, 25, 220, 220);
  circle(100, 100, 50);
  等等*****/
     sqrtCircle(50,105);
     funCircle(50,5);
     BresenhamCircle(50,35);
     MidPointCircle(50,255);
     sqrtEllipse(50,80,220);
     funEllipse(50,80,180);
     MidPointEllipse(50,80,150);
  getch(); /* 暫停一下，看看前面繪圖代碼的運行結果 */
  closegr(); /* 恢復TEXT屏幕模式 */
  return 0;
}