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TCrossFunction -- can I get the returnvalue of the crosspoint?
Posted: Fri Mar 03, 2023 3:09 pm
by 16592373
series 1 and series2 is crossing .. but how do I get the value of the cross point
Re: TCrossFunction -- can I get the returnvalue of the crosspoint?
Posted: Fri Mar 03, 2023 4:52 pm
by 16595372
Do i understand correctly that the first point in the parent series is the first cross point?
Code: Select all
repeat
if LinesCross(index1,index2,x,y) then
ParentSeries.AddXY(x,y);
Re: TCrossFunction -- can I get the returnvalue of the crosspoint?
Posted: Mon Mar 06, 2023 10:57 am
by yeray
Hello,
Yes, the series you assign the
TCrossPointsFunction to contains the crossing points.
Ie:
- Project1_2023-03-06_12-00-21.png (27.65 KiB) Viewed 24700 times
Code: Select all
uses Vcl.StdCtrls, VCLTee.TeeGDIPlus, VCLTee.Chart, VCLTee.Series, VCLTee.StatChar;
var Chart1: TChart;
line1, line2: TLineSeries;
crossFunction: TCrossPointsFunction;
crossPoints: TPointSeries;
Memo1: TMemo;
procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
Chart1:=TChart.Create(Self);
Chart1.Parent:=Self;
Chart1.Align:=alClient;
Chart1.View3D:=False;
Chart1.Legend.Hide;
Memo1:=TMemo.Create(Self);
Memo1.Parent:=Self;
Memo1.Align:=alRight;
line1:=TLineSeries(Chart1.AddSeries(TLineSeries));
line2:=TLineSeries(Chart1.AddSeries(TLineSeries));
line1.FillSampleValues;
line2.FillSampleValues;
crossFunction:=TCrossPointsFunction.Create(Self);
crossPoints:=TPointSeries(Chart1.AddSeries(TPointSeries));
crossPoints.Pointer.Size:=2;
crossPoints.FunctionType:=crossFunction;
crossPoints.DataSources.Add(line1);
crossPoints.DataSources.Add(line2);
Memo1.Lines.Add('Crossing Points:');
with crossPoints do
for i:=0 to Count-1 do
Memo1.Lines.Add('X: '+FormatFloat(ValueFormat, XValues[i])+', Y: '+FormatFloat(ValueFormat, YValues[i]));
end;
Re: TCrossFunction -- can I get the returnvalue of the crosspoint?
Posted: Tue Mar 07, 2023 12:06 pm
by 16592373
thanks ..clear! but..
where exactly is the trigger for the final painting of the chart and lines.
I try to debug step by step in Tee9New.. but get lost.
is it here?
------ from Base Form---------------
ncGDIPlus : if not (Chart1.Canvas is TGLCanvas) then // <-- For demos with default OpenGL Canvas, do not change it !
if not (Chart1.Canvas is TGDIPlusCanvas) then // <-- Do not assign a GDI+ canvas if it already is !
Chart1.Canvas:=TGDIPlusCanvas.Create;
{$ENDIF}
else
Chart1.Canvas:=TTeeCanvas3D.Create;
Re: TCrossFunction -- can I get the returnvalue of the crosspoint?
Posted: Tue Mar 07, 2023 2:30 pm
by yeray
Hello,
I'm not sure what are you trying to achieve.
In the example I posted above, the calculation of the crossing points starts as soon as the second series is added to the crossPoints DataSources.