Mega Code Archive
Drawing at an angle
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Title: Drawing at an angle
Question: Rotating an image
Answer:
paste a button and a image on a form and select a bitmap for the bitmap prefarely not too big about 100x100
and paste this unit.
unit drawunit;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
Image1: TImage;
Button1: TButton;
procedure Button1Click(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
rotateimage:timage;
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
const
rotation = 2/3*pi;
var
x,y : integer;
newx,newy : integer;
radius,a : real;
begin
form1.WindowState:=wsMaximized;
image1.Visible:=false;
button1.Visible:=false;
rotateimage:=timage.Create(self);
rotateimage.parent:=self;
rotateimage.Left:=0;
rotateimage.Top:=0;
rotateimage.width:=740;
rotateimage.Height:=540;
for x:=1 to image1.Picture.Width do
begin
for y:=1 to image1.Height do
begin
radius:=Sqrt(Sqr(X)+Sqr(Y));
a:=Arctan(Y/X);
newx:=round(Radius*Cos(A+Rotation)+300);
newy:=round(Radius*Sin(A+Rotation)+300);
rotateimage.Canvas.Pixels[newx,newy]:=image1.Canvas.Pixels[x,y];
end;//nested for do
end;//for do
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
rotateimage.free;
end;
end.
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