Point Function

Hi All,

Point function of Form object returns color of the pixel at a
partcular location on the form.

I tried to use this function in a project of Graphics.

I found that the behaviour of the function was strange.

Sometimes, the function returned a color value upon clicking
a pixel on form.

Other times, it simply falied to return anything.
It just kept returning -1 eventhought the color of the pixel was red.

The same code worked on other PCs while on still others it failed.

Can anyone explain why Point function behaves like this ?

I need a quick reply.

Thank you.

The Point function normally returns -1 if the coordinates you specify is outside of the Form border. Could you post the code you used?

I think it even returns -1 if the mouse cursor is over objects as well. Correct me if I'm wrong but I remember that happening to me in the past.

That is true unless the ClipControls property is set to False.

Hi Jacob,
Here is the code you want.
If you know computer graphics, it is about BoundaryFill Algorithm that fills
a polygon. If you need any further code, just inform me. Thanks.

Public Sub BoundaryFill4(xf As Single, yf As Single, FillCol As ColorConstants, BoundaryCol As ColorConstants)



Dim current As ColorConstants

current = Point(xf, yf)



If ((current <> BoundaryCol) And (current <> FillCol)) Then

Me.PSet (xf, yf), FillCol

Call BoundaryFill4(xf + 1, yf, FillCol, BoundaryCol)

Call BoundaryFill4(xf - 1, yf, FillCol, BoundaryCol)

Call BoundaryFill4(xf, yf + 1, FillCol, BoundaryCol)

Call BoundaryFill4(xf, yf - 1, FillCol, BoundaryCol)

End If

Does that solve your problem?