Affine transformation (C++ Builder)

private: // User declarations

  float x1[5],y1[5],x2[5],y2[5],x3[5],y3[5];

  void __fastcall init_Random();

  float __fastcall is_Minus(float value);

  void __fastcall init_Arrays();

void __fastcall TForm1::init_Random()

{

srand(time(NULL));

}

float __fastcall TForm1::is_Minus(float value)

{

int x;

x=rand()%12;

if(x==0)

value*=-1.;

else if(x==1)

value=0.;

else if(x==2)

value=0.;

else if(x==3)

value*=-1.;

return value;

}

void __fastcall TForm1::init_Arrays()

{

int i;

for(i=0;i<5;i++)

{

x1[i]=is_Minus((1.*(rand()%100))/100.);

x2[i]=is_Minus((1.*(rand()%100))/100.);

x3[i]=is_Minus((1.*(rand()%100))/100.);

y1[i]=is_Minus((1.*(rand()%100))/100.);

y2[i]=is_Minus((1.*(rand()%100))/100.);

y3[i]=is_Minus((1.*(rand()%100))/100.);

}

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)

{

 Close();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::FormCreate(TObject *Sender)

{

 init_Random();

 init_Arrays();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::FormPaint(TObject *Sender)

{

 int i,j;

 float a,b;

 a=1.*(rand()%65535);

 b=1.*(rand()%65535);

 i=0;

 do

 {

  j=rand()%5;

  switch(j)

  {

 case 0: a=a*x1[0]+b*y1[0]+x2[0]; b=a*y2[0]+b*x3[0]+y3[0];break;

 case 1: a=a*x1[1]+b*y1[1]+x2[1]; b=a*y2[1]+b*x3[1]+y3[1];break;

 case 2: a=a*x1[2]+b*y1[2]+x2[2]; b=a*y2[2]+b*x3[2]+y3[2];break;

 case 3: a=a*x1[3]+b*y1[3]+x2[3]; b=a*y2[3]+b*x3[3]+y3[3];break;

 case 4: a=a*x1[4]+b*y1[4]+x2[4]; b=a*y2[4]+b*x3[4]+y3[4];break;

  }

  Canvas->Pixels[Form1->Width/2+Floor(40*a)][Form1->Height/2-Floor(40*b)]=RGB(rand()%255,rand()%255,rand()%255);

  i++;

}while(i<9000000);

}