Point Function

[varun_789]

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.

[Joacim Andersson]

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

[Jacob Roman]

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.

[Joacim Andersson]

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

[varun_789]

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

[dglienna]

Does that solve your problem?