B4J Question B4XCanvas - InitializeArc looks different than in B4A

[Alexander Stolte]

Hey,
why it look in B4J so?:

and on B4A only the right outer line is to watch?

Dim tmp_bp As B4XPath
    tmp_bp.InitializeArc(xcv_main.TargetRect.CenterX,xcv_main.TargetRect.CenterY,Height/2,10,20)   
    xcv_main.DrawPath(tmp_bp,xui.Color_Blue,False,5dip)

 

[Star-Dust]

Hey,
why it look in B4J so?:
View attachment 94362
and on B4A only the right outer line is to watch?

Dim tmp_bp As B4XPath
    tmp_bp.InitializeArc(xcv_main.TargetRect.CenterX,xcv_main.TargetRect.CenterY,Height/2,10,20) 
    xcv_main.DrawPath(tmp_bp,xui.Color_Blue,False,5dip)

Behaviors are different. In B4A the path is closed, if you don't want to close it you have to use the lines not the path.

In B4J the path is not closed, If you want to close you must bring an end point coinciding with the starting point

 

[Alexander Stolte]

my goal is this:

 

[Star-Dust]

my goal is this:
View attachment 94364

On one occasion I used the lines with Sin and Cos I found the points and drew a series of lines. Depending on the radius and the step of degrees you choose, you can get a better (or worse) arc precision

 

[Star-Dust]

Something like that

    Dim X as Float ' Center
    Dim Y as Float ' Center
    Dim LastX as float = 0
    Dim LastY as Float = 0

For i=StartDegree To EndDegree
        Dim x1 As Float = x + ray * CosD(i/2)
        Dim Y1 As Float = y + ray * SinD(i/2)
        if LastX<>0 and LastY<>0 Then DravLine(LastX,LastY,X1,Y1)
        
        LastX=X1
        LastY=Y1
    Next

 

[Erel]

Check BitmapCreator. It can draw arcs and the behavior will be the same in all platforms.