Mine

//---------------------------------------------------------------------------#include <vcl.h>#pragma hdrstop#include "Unit1.h"//---------------------------------------------------------------------------#pragma package(smart_init)#pragma resource "*.dfm"TForm1 *Form1;//---------------------------------------------------------------------------__fastcall TForm1::TForm1(TComponent* Owner)	: TForm(Owner){}//---------------------------------------------------------------------------void __fastcall TForm1::FormCreate(TObject *Sender){	b=new Graphics::TBitmap;	b->LoadFromResourceID((int)HInstance, 100);	ClientWidth=b->Width;	ClientHeight=b->Height;	for(int x = 0; x < 5; x++)		for (int y = 0; y < 5; y++)			o[x][y]=CreateRectRgn(				x*b->Width/5, y*b->Height/5,				(x+1)*b->Width/5, (y+1)*b->Height/5);	p=CreateRectRgn(0,0,0,0);}//---------------------------------------------------------------------------void __fastcall TForm1::FormDestroy(TObject *Sender){	delete b;	for(int x=0; x<5; x++)		for (int y=0; y<5; y++)			DeleteObject(o[x][y]);	DeleteObject(p);}//---------------------------------------------------------------------------void __fastcall TForm1::FormPaint(TObject *Sender){	SelectClipRgn(Canvas->Handle, p);	Canvas->Draw(0,0,b);}//---------------------------------------------------------------------------void __fastcall TForm1::FormMouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,		  int X, int Y){	for(int x=0; x<5; x++)		for (int y=0; y<5; y++)			if (PtInRegion(o[x][y],X,Y))				CombineRgn(p,p,o[x][y],RGN_OR);	InvalidateRect(Handle,NULL,FALSE);}//---------------------------------------------------------------------------