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...shape a form to a bitmap?
Autor: Pascal Enz
[ Print tip ]  

Tip Rating (8):  
     


unit Unit1;

interface

uses
  
Windows, Classes, SysUtils, Graphics, Forms;

type
  
TRGBArray = array[0..32767] of TRGBTriple;
  PRGBArray = ^TRGBArray;

type
  
TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    
{ Private declarations }
    
FRegion: THandle;
    function CreateRegion(Bmp: TBitmap): THandle;
  end;

var
  
Form1: TForm1;

implementation

{$R *.dfm}

function TForm1.CreateRegion(Bmp: TBitmap): THandle;
var
  
X, Y, StartX: Integer;
  Excl: THandle;
  Row: PRGBArray;
  TransparentColor: TRGBTriple;
begin
  
Bmp.PixelFormat := pf24Bit;

  Result := CreateRectRGN(0, 0, Bmp.Width, Bmp.Height);

  for Y := 0 to Bmp.Height - 1 do
  begin
    
Row := Bmp.Scanline[Y];

    StartX := -1;

    if Y = 0 then
      
TransparentColor := Row[0];

    for X := 0 to Bmp.Width - 1 do
    begin
      if 
(Row[X].rgbtRed = TransparentColor.rgbtRed) and
        
(Row[X].rgbtGreen = TransparentColor.rgbtGreen) and
        
(Row[X].rgbtBlue = TransparentColor.rgbtBlue) then
      begin
        if 
StartX = -1 then StartX := X;
      end
      else
      begin
        if 
StartX > -1 then
        begin
          
Excl := CreateRectRGN(StartX, Y, X + 1, Y + 1);
          try
            
CombineRGN(Result, Result, Excl, RGN_DIFF);
            StartX := -1;
          finally
            
DeleteObject(Excl);
          end;
        end;
      end;
    end;

    if StartX > -1 then
    begin
      
Excl := CreateRectRGN(StartX, Y, Bmp.Width, Y + 1);
      try
        
CombineRGN(Result, Result, Excl, RGN_DIFF);
      finally
        
DeleteObject(Excl);
      end;
    end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  
Bmp: TBitmap;
begin
  
Bmp := TBitmap.Create;
  try
    
Bmp.LoadFromFile('C:\YourBitmap.bmp');
    FRegion := CreateRegion(Bmp);
    SetWindowRGN(Handle, FRegion, True);
  finally
    
Bmp.Free;
  end;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  
DeleteObject(FRegion);
end;

end.


 

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