farbverlauf in %

[mr_emre_d]

Delphi-Quellcode:

function Gradient( ACanvas: TCanvas;
  Pos: TRect; const FromColor, ToColor: Cardinal ): Boolean;
var
  x: Integer;
  NewColor: Cardinal;
  Percent: Single;
  rOP, gOP, bOP: Single;  // One Percent
begin
  Result := False;
  {Initialization}
  Pos.Right  := Pos.Right - Pos.Left;  // Right  = Width
  Pos.Bottom := Pos.Bottom - Pos.Top;  // Bottom = Height
  with ACanvas do
  begin
    rOP := (GetRValue(ToColor)-GetRValue(FromColor)) / Pos.Right;
    gOP := (GetGValue(ToColor)-GetGValue(FromColor)) / Pos.Right;
    bOP := (GetBValue(ToColor)-GetBValue(FromColor)) / Pos.Right;
    for x := 1 to Pos.Right do
    begin
      NewColor := RGB( GetRValue(FromColor)+Round(rOP*x),
        GetGValue(FromColor)+Round(gOP*x),
        GetBValue(FromColor)+Round(bOP*x) );
      Pen.Color := NewColor;
      MoveTo( Pos.Left+x, Pos.Top );
      LineTo( Pos.Left+x, Pos.Top+Pos.Bottom );
    end;
  end;
  Result := not Result;
end;