B4J Question [B4X] Why does B4XCanvas use float when the coordinate systems uses doubles?

Erel

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• Aug 3, 2020

• #2

Moved to the questions forum.

B4XCanvas is a cross platform type and It is the same API as in B4A and B4i, which are based on floats.
I don't think that there is any case in B4J where it will matter that the floats are cast to double.

 

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keirS

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• Aug 3, 2020

• #3

I am using B4XRect to define bounding boxes.. So it's a case of casting a double to a float. Isn't it possible there could be edge cases where the B4XView touch action coordinates would be inside the bounding box if a double was used and outside when using a float?

 

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Erel

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• Aug 3, 2020

• #4

No.

B4X:

Sub Pane1_MouseMoved (EventData As MouseEvent)
    Log(EventData.X)
End Sub

You will see that it is pixel based.

 

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keirS

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• Aug 3, 2020

• #5

I am not using the MouseMoved event. I am using the TOUCH_ACTION_UP, TOUCH_ACTION_DOWN and TOUCH_ACTION_MOVE events for cross platform compatability hence my question.
.

 

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Erel

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• Aug 3, 2020

• #6

It doesn't matter. The precision of float is much higher than the precision of the various mouse events.

 

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