3D Zoom Fit

[to2]

I'd like to draw waterfall series and allow the user to change rotation and elevation. Depending on rotation, elevation, zoom and Chart3DPercent corners of the chart may be positioned outside of the visible area. After every change of rotation, elevation and Chart3DPercent I'd like to zoom the chart in a way that it fits best into the visible area. How can I do that?

p.s. I'm using TeeChart 8.08.

[Narcís]

Hi to2,

It's a little bit complicated but can be achieved using the "Protected Hack" with the TTeeCanvas3D class and the code below. Find also attached the complete project:

Code: Select all

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, TeeGDIPlus, TeEngine, TeeComma, ExtCtrls, TeeProcs, Chart, TeCanvas;

type
  TForm1 = class(TForm)
    TeeCommander1: TTeeCommander;
    Chart1: TChart;
    procedure FormCreate(Sender: TObject);
    procedure Chart1AfterDraw(Sender: TObject);
  private
    { Private declarations }
    Procedure RectangleWithZ(Const Rect:TRect; var FPoints: TFourPoints; Z:Integer);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses Series, TeeSurfa, TeeTools;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chart1.AddSeries(TSurfaceSeries.Create(Self)).FillSampleValues();
  Chart1.Chart3DPercent:=100;
  Chart1.Aspect.Orthogonal:=False;

  Chart1.Tools.Add(TRotateTool.Create(Self));
  //(Chart1.Tools.Items[0] as TRotateTool).Pen.Visible:=True;
end;

procedure TForm1.Chart1AfterDraw(Sender: TObject);
var
  FourPoints : TFourPoints;
  FourPointsZ : TFourPoints;
begin
  RectangleWithZ(Chart1.ChartRect, FourPoints, 0);
  RectangleWithZ(Chart1.ChartRect, FourPointsZ, Chart1.Width3D);

  if not PointInRect(Chart1.ChartBounds, FourPoints[0].X, FourPoints[0].Y) or
      not PointInRect(Chart1.ChartBounds, FourPoints[1].X, FourPoints[1].Y) or
      not PointInRect(Chart1.ChartBounds, FourPoints[2].X, FourPoints[2].Y)  or
      not PointInRect(Chart1.ChartBounds, FourPoints[3].X, FourPoints[3].Y) or
      not PointInRect(Chart1.ChartBounds, FourPointsZ[0].X, FourPoints[0].Y) or
      not PointInRect(Chart1.ChartBounds, FourPointsZ[1].X, FourPoints[1].Y) or
      not PointInRect(Chart1.ChartBounds, FourPointsZ[2].X, FourPoints[2].Y)  or
      not PointInRect(Chart1.ChartBounds, FourPointsZ[3].X, FourPoints[3].Y) then
  begin
    Chart1.Aspect.Zoom:=Chart1.Aspect.Zoom - 10;
  end;
end;

type
  TCanvas3DAccess=class(TTeeCanvas3D);

Procedure TForm1.RectangleWithZ(Const Rect:TRect; var FPoints: TFourPoints; Z:Integer);
begin
  With Rect, TCanvas3DAccess(Chart1.Canvas) do
  begin
    Calc3DPoint(FPoints[0],Left,Top,Z);
    Calc3DPoint(FPoints[1],Right,Top,Z);
    Calc3DPoint(FPoints[2],Right,Bottom,Z);
    Calc3DPoint(FPoints[3],Left,Bottom,Z);
  end;
end;

end.

[to2]

can be achieved using the "Protected Hack"

Thank you very much, Narcís. While trying it I've realized, it is not that simple to do the Protected Hack in BCB. I wonder, if Calc3DPoint can be done by using other functions like Calculate3DPosition.

[to2]

I wonder, if Calc3DPoint can be done by using other functions

-> FourPointsFromRect works.