SetSrcRect example for C++ Builder
This example zooms in on the image by reducing the source rectangle and repaints the image.
void __fastcall TForm1::Button1Click(TObject *Sender)
{
int NewLeft, NewTop, NewWidth, NewHeight;
NewLeft = Lead1->SrcLeft+ Lead1->SrcWidth / 10;
NewTop = Lead1->SrcTop + Lead1->SrcHeight / 10;
NewWidth = Lead1->SrcWidth * 8 / 10;
NewHeight = Lead1->SrcHeight * 8 / 10;
if( (NewWidth > 1) && (NewHeight >1))
Lead1->SetSrcRect(NewLeft, NewTop, NewWidth, NewHeight);
Lead1->ForceRepaint();
}