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unit main;
{$mode objfpc}{$H+}
interface
uses
Classes, ExtCtrls, StdCtrls, SysUtils, TAGraph, TAFuncSeries,
TASources, Forms, Controls, Graphics, Dialogs, TATypes, TATools, Types;
type
{ TForm1 }
TForm1 = class(TForm)
Chart1: TChart;
Chart1ColorMapSeries1: TColorMapSeries;
ChartToolset1: TChartToolset;
ChartToolset1PanDragTool1: TPanDragTool;
ChartToolset1UserDefinedTool1: TUserDefinedTool;
ChartToolset1UserDefinedTool2: TUserDefinedTool;
ChartToolset1ZoomDragTool1: TZoomDragTool;
ColorSource: TListChartSource;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Label5: TLabel;
Label6: TLabel;
Label7: TLabel;
Label8: TLabel;
Label9: TLabel;
LblMagnification: TLabel;
LblHistoryCount: TLabel;
Panel1: TPanel;
Panel2: TPanel;
Panel3: TPanel;
procedure Chart1ColorMapSeries1Calculate(const AX, AY: Double;
out AZ: Double);
procedure Chart1ExtentChanged(ASender: TChart);
procedure ChartToolset1PanDragTool1AfterMouseDown(ATool: TChartTool;
APoint: TPoint);
procedure ChartToolset1UserDefinedTool1AfterMouseUp(ATool: TChartTool;
APoint: TPoint);
procedure ChartToolset1UserDefinedTool2AfterMouseUp(ATool: TChartTool;
APoint: TPoint);
procedure ChartToolset1ZoomDragTool1AfterMouseUp(ATool: TChartTool;
APoint: TPoint);
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
ZoomHistory: TChartExtentHistory;
procedure PopulateColorSource;
end;
var
Form1: TForm1;
implementation
{$R *.lfm}
uses
StrUtils,
TAChartUtils, TAGeometry;
const
MANDELBROT_NUM_ITERATIONS = 100;
MANDELBROT_ESCAPE_RADIUS = 2.0;
MANDELBROT_LIMIT = sqr(MANDELBROT_ESCAPE_RADIUS);
function InMandelBrotSet(
AC: TDoublePoint; out AIterations: Integer; out AZ: TDoublePoint): Boolean;
var
j: Integer;
begin
AIterations := 0;
AZ := DoublePoint(0.0, 0.0);
for j := 0 to MANDELBROT_NUM_ITERATIONS - 1 do begin
AZ := DoublePoint(
Sqr(AZ.X) - Sqr(AZ.Y) + AC.X,
2 * AZ.X * AZ.Y + AC.Y);
if Sqr(AZ.X) + Sqr(AZ.Y) > MANDELBROT_LIMIT then
// point did escape --> AC is not in Mandelbrot set
exit(false);
AIterations += 1;
end;
Result := true;
end;
{ TForm1 }
procedure TForm1.FormCreate(Sender:TObject);
begin
PopulateColorSource;
ZoomHistory := TChartExtentHistory.Create;
ZoomHistory.Capacity := 100;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
ZoomHistory.Free;
end;
procedure TForm1.Chart1ColorMapSeries1Calculate(
const AX, AY: Double; out AZ: Double);
var
iterations: Integer;
z: TDoublePoint;
begin
if InMandelBrotSet(DoublePoint(AX, AY), iterations, z) then
AZ := -1
// or - as a solution to the "homework" exercise:
// AZ := sqrt(sqr(z.x) + sqr(z.y)) / MANDELBROT_ESCAPE_RADIUS
else
AZ := iterations / MANDELBROT_NUM_ITERATIONS;
end;
procedure TForm1.Chart1ExtentChanged(ASender: TChart);
var
cex, fex: TDoubleRect;
factor: Double;
begin
cex := ASender.CurrentExtent;
fex := ASender.GetFullExtent;
if cex.b.x = cex.a.x then exit;
factor := (fex.b.x - fex.a.x) / (cex.b.x - cex.a.x);
LblMagnification.Caption :=
'Magnification: ' + Format(IfThen(factor > 1e6, '%.0e', '%0.g'), [factor]);
LblHistoryCount.Caption := Format('History count: %d', [ZoomHistory.Count]);
end;
procedure TForm1.ChartToolset1PanDragTool1AfterMouseDown(
ATool: TChartTool; APoint: TPoint);
begin
Unused(ATool, APoint);
ZoomHistory.Add(Chart1.PrevLogicalExtent);
end;
procedure TForm1.ChartToolset1UserDefinedTool1AfterMouseUp(
ATool: TChartTool; APoint: TPoint);
begin
Unused(ATool, APoint);
if ZoomHistory.Count > 0 then
Chart1.LogicalExtent := ZoomHistory.Pop;
end;
procedure TForm1.ChartToolset1UserDefinedTool2AfterMouseUp(
ATool: TChartTool; APoint: TPoint);
begin
Unused(ATool, APoint);
Chart1.ZoomFull;
end;
procedure TForm1.ChartToolset1ZoomDragTool1AfterMouseUp(
ATool: TChartTool; APoint: TPoint);
begin
Unused(ATool, APoint);
ZoomHistory.Add(Chart1.PrevLogicalExtent);
end;
procedure TForm1.PopulateColorSource;
const
DUMMY = 0.0;
begin
with ColorSource do begin
Clear;
Add(-1.0, DUMMY, '', clBlack);
Add( 0.0, DUMMY, '', clBlue);
Add( 0.3, DUMMY, '', clRed);
Add( 1.0, DUMMY, '', clYellow);
end;
end;
end.
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