Fractal program

Development Platform:
Visual C++

fractus4_05.cpp：Code Content
							//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop
#include "fractus4_05.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
#include "glib.h"
const int KL=300;
const double BOX=0.01;
const int STEP=1;
int sx,sy,dx=192,dy=192;
double x_min,x_max,y_min,y_max;
double x0,y0;
double a1,b1,a2,b2;
int (*col)[2];
int col_1[][2]={{6,4},{8,1},{12,2},{18,5},{KL+1,6}},
    col_2[][2]={{18,4},{24,1},{36,2},{54,5},{KL+1,6}},
    col_3[][2]={{30,4},{36,1},{48,2},{66,5},{KL+1,6}};
double delta=0.0001;TRect rect;
int colors[16]={0x00000000,0x00FF0000,0x0000FF00,0x00FF8C00,
                0x000000FF,0x00FF00FF,0x0000FFFF,0x00A0A0A0,
                0x009BFFFF,0x009BFFFF,0x00A0FF00,0x00FFFF00,
                0x006E6EFF,0x00FF9BFF,0x009BFFFF,0x00FFFFFF};
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
//按发散区域分类的曼代尔波集合
void __fastcall coord(void)
 {a1=(x_max-x_min)/(2*dx);
  b1=(x_max+x_min)/2;
  a2=(y_max-y_min)/(2*dy);
  b2=(y_max+y_min)/2;
 }
//---------------------------------------------------------------------------
int __fastcall getcol(int k)
 {int i=0;
  while(k>col[i][0]&&k<=KL)
    i++;
  return col[i][1];
 }
//---------------------------------------------------------------------------
void __fastcall plot(int col)
 {putpixel(sx,-sy,colors[col]);
  putpixel(sx,sy,colors[col]);
 }
//---------------------------------------------------------------------------
void mandelbrot(void)
 {int k;double s;
  static double x[KL+1],y[KL+1];
  x[0]=x0;y[0]=y0;
  for(k=1;k<=KL;k++)
   {x[k]=x[k-1]*x[k-1]-y[k-1]*y[k-1]+x0;
    y[k]=2*x[k-1]*y[k-1]+y0;
    if((x[k]*x[k]+y[k]*y[k])>=4.0)
     {plot(getcol(k));return;}
   }
 }
//---------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
  Image1->Height=0;Image1->Top=0;
  Image1->Width=Screen->Width;Image1->Height=Screen->Height;
  rect=Rect(0,0,Image1->Width,Image1->Height);//清屏
  Image1->Canvas->CopyMode=cmBlackness;
  Image1->Canvas->CopyRect(rect,Image1->Canvas,rect);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N1Click(TObject *Sender)
{
  Image1->Canvas->CopyRect(rect,Image1->Canvas,rect);
  set0(320,200);
  coord();
  for(sx=-dx;sx<=dx;sx+=STEP)
   {x0=a1*sx+b1;
    for(sy=0;sy<=dy;sy+=STEP)
     {y0=a2*sy+b2;
      mandelbrot();
     }
   }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N2Click(TObject *Sender)
{
  if(SavePictureDialog1->Execute())
    Image1->Picture->SaveToFile(SavePictureDialog1->FileName);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N3Click(TObject *Sender)
{
  Close();        
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N4_1Click(TObject *Sender)
{
  x_min=-2.2;x_max=0.6;
  y_min=-1.4;y_max=1.4;
  col=col_1;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N4_2Click(TObject *Sender)
{
  x_min=-1.8;x_max=-1.74;
  y_min=-0.03;y_max=0.03;
  col=col_2;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::N4_3Click(TObject *Sender)
{
  x_min=-1.49;x_max=-1.47;
  y_min=-0.01;y_max=0.01;
  col=col_3;
}
//---------------------------------------------------------------------------

						