Android Question [Solved] RotatingNeedle-Example: Question to comprehend

[Pflichtfeld]

In this example, I find these lines:

wc = bmpCompass.Width * 100dip / 100
hc = bmpCompass.Height * 100dip / 100
wn = bmpNeedle.Width * 100dip / 100
hn = bmpNeedle.Height * 100dip / 100

Would there be a difference to:

wc = bmpCompass.Width * 1dip
...

or to

wc=(DipToCurrent(bmpCompass.Width))
...

or is there a reason for this "100dip/100"

 

[Jorge M A]

You can find the reason in this video tutorial:

B4X Programming Video Tutorials

www.b4x.com

 

[Pflichtfeld]

You can find the reason in this video tutorial:

thank you Jorge. At 9:25 Erel also uses 100dip/100, but does not explain why he takes this quotient and not just 1dip or dipTo Current.

 

[Pflichtfeld]

I think, I found out the reason myself:
DipToCurrent (Length As Int) As Int
is the definition and I suppose, that that can be unexact in some cases, because it does not return a single or float?
Is this the reason?

 

[klaus]

Yes.
With scales of 0.75 and 1.5 it will be wrong.
I remember also that InitializeMutable(1dip, 1dip) did through an error with a 0.75 scale.

 

[Pflichtfeld]

Yes.
With scales of 0.75 and 1.5 it will be wrong.

Thank you Klaus!