I am using Steema TChart in a C++ Builder program, and I need to draw lines, with a user defined inclination, that passes through a point and goes up to the limits of the TChart. By limits, I mean the rectangule that surrounds the graphic.
In the image below you can see that the lines go beyond the rectangle I mentioned.
Any help will be much appreciated!
You can draw manually those lines. Ie, in delphi:
uses Series, Math, TeCanvas;
procedure TForm1.Chart1AfterDraw(Sender: TObject);
procedure DrawLine(ASeries: TChartSeries; ValueIndex: Integer; Angle: Integer);
var P, P0, P1: TPoint;
Alfa, AlfaTan: Double;
R: TRect;
Canvas: TCanvas3D;
begin
Alfa:=Angle*TeePiStep;
R:=ASeries.ParentChart.ChartRect;
Canvas:=ASeries.ParentChart.Canvas;
P:=Point(ASeries.CalcXPos(ValueIndex), ASeries.CalcYPos(ValueIndex));
if Angle mod 180 = 0 then
begin
if (P.Y > R.Top) and (P.Y < R.Bottom) then
Canvas.HorizLine3D(R.Left, R.Right, P.Y, 0);
end
else if Angle mod 90 = 0 then
begin
if (P.X > R.Left) and (P.X < R.Right) then
Canvas.VertLine3D(P.X, R.Top, R.Bottom, 0);
end
else
begin
AlfaTan:=Tan(Alfa);
P0.Y:=P.Y+Round(AlfaTan*(P.X-R.Left));
P0.X:=R.Left;
if (P0.Y < R.Top) then
begin
P0.Y:=R.Top;
P0.X:=P.X-Round((R.Top-P.Y)/AlfaTan);
end
else if (P0.Y > R.Bottom) then
begin
P0.Y:=R.Bottom;
P0.X:=P.X-Round((R.Bottom-P.Y)/AlfaTan);
end;
P1.Y:=P.Y-Round(AlfaTan*(R.Right-P.X));
P1.X:=R.Right;
if (P1.Y < R.Top) then
begin
P1.Y:=R.Top;
P1.X:=P.X-Round((R.Top-P.Y)/AlfaTan);
end
else if (P1.Y > R.Bottom) then
begin
P1.Y:=R.Bottom;
P1.X:=P.X-Round((R.Bottom-P.Y)/AlfaTan);
end;
Canvas.Line(P0, P1);
end;
end;
begin
DrawLine(Chart1[0], 2, 180);
DrawLine(Chart1[0], 2, 165);
DrawLine(Chart1[0], 2, 150);
DrawLine(Chart1[0], 2, 120);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Chart1.View3D:=False;
Chart1.AddSeries(TPointSeries).FillSampleValues(5);
end;