On 18/09/2014 17:41, Giuliano Colla wrote:
Canvas.RadalPie on GTK2 and Windows works only clockwise, but provides a
very poor image (more like a portion of an octagon that a portion of a
circle).
Counterclockwise it generates the image of my previous e-mail.
On Windows here, Pie (RadialPie) works counterclockwise well, using the
following code example.
I'm sure if you added anitaliasing to improve the rendering quality this
would be welcomed.
Howard
== code ==
unit Unit1;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, Forms, Controls, Graphics;
type
{ TForm1 }
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
procedure FormPaint(Sender: TObject);
private
end;
TPieRec = record
percentage: integer; // give pie segments as percentag of whole pie
color: TColor;
end;
TPieArray = array of TPieRec;
procedure DrawPie(aCanvas: TCanvas; aCircleRect: TRect; pa: TPieArray);
var
Form1: TForm1;
implementation
procedure DrawPie(aCanvas: TCanvas; aCircleRect: TRect; pa: TPieArray);
var
angles: array of integer;
lastAngle: integer = 0;
i: Integer;
begin
SetLength(angles, Length(pa));
for i:=0 to High(pa) do begin
angles[i]:=trunc(pa[i].percentage * 57.60);
aCanvas.Brush.Color:=pa[i].color;
aCanvas.RadialPie(aCircleRect.Left, aCircleRect.Top,
aCircleRect.Right, aCircleRect.Bottom,
lastAngle, angles[i]);
Inc(lastAngle, angles[i]);
end;
end;
{$R *.lfm}
{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
end;
procedure TForm1.FormPaint(Sender: TObject);
var
example: TPieArray;
circleRect: TRect;
begin
circleRect:=Rect(10,10,110,110);
SetLength(example, 4);
example[0].percentage:=30; example[0].color:=clBlue;
example[1].percentage:=10; example[1].color:=clRed;
example[2].percentage:=20; example[2].color:=clYellow;
example[3].percentage:=40; example[3].color:=clMoneyGreen;
DrawPie(Canvas, circleRect, example);
end;
end.
--
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