Screen Point to Chart Coordinates

[bvsimmons]

Is there a way to obtain the Chart X and Y coordinates from a screen X, Y (mouse coordinates).

Thanks
Bernard

[Yeray]

Hello,

You can use the Axis' CalcPosPoint to transform screen pixels to axis values. Ie:

Code: Select all

var XPixel: Integer;
    XValue: Double;
  //...
  XValue:=Chart1.Axes.Bottom.CalcPosPoint(XPixel);

Note you can also transform Axis values to screen pixels with CalcPosValue function. Ie:

Code: Select all

var XPixel: Integer;
    XValue: Double;
  //...
  XPixel:=Chart1.Axes.Bottom.CalcPosValue(XValue);

Another pair useful functions is the Series' CalcXPos/CalcYPos, returning the pixel position for a given ValueIndex. Ie:

Code: Select all

var XPixel, YPixel, ValueIndex: Integer;
    Series1: TPointSeries;
  //...
  XPixel:=Series1.CalcXPos(ValueIndex);
  YPixel:=Series1.CalcYPos(ValueIndex);

[bvsimmons]

Thanks for your response.

Where can I find the function 'CalcPosPixel' I have searched all of the directories under Steema TeeChart Pro VCL FMX 2017.22 but have not found it.

Bernard

[bvsimmons]

Never mind, I found it, in C++ Builder it's Chart1->Series->CalcXPosValue(.....

Thanks

Bernard