Android Question [XUI] drawing a dashed circle

[Andrew (Digitwell)]

I would like to draw a dashed circle.

I have come up with this algorithm which uses initializearc, but it does not feel very efficient. Is there a better way?

    Dim c As B4XCanvas
    c.Initialize(xview) ' view to draw on, assume a square

        Private path As B4XPath
        Private i As Int
        For i = 0 To 360 Step 30
            path.InitializeArc(c.targetrect.CenterX,c.TargetRect.CenterY,(c.TargetRect.Width / 2)-1dip,i,20)
            c.DrawPath(path,outlinecolour,False,2dip) ' Draw arc, not filled
            
        Next
        'remove all of the "spokes"
        Private pathin As B4XPath
        Private rt As B4XRect
        rt.Initialize(2dip,2dip,c.TargetRect.Right-2dip,c.TargetRect.Bottom-2dip)
        pathin.InitializeOval(rt)
        c.ClipPath(pathin)
        c.ClearRect(rt)
        c.RemoveClip
    c.Invalidate

    c.Release

 

[Erel]

Can you post an image with the desired result?

 

[Andrew (Digitwell)]

Here is a sample from the app screen, I am using it to draw the green line around the date. I had simplified the code to remove the date display etc

It works, I was just wondering if there was a better way.

 

[Erel]

but it does not feel very efficient

If your code produces the desired results and you are worried about its performance then you should measure it. Make sure to do it in release mode.

My guess is that it is already fast enough.

 

[MarkusR]

i think DrawPathRotated is better, one block (path) with 6 or 8 points painted 12x
u define inner and outer radius, with SinD & CosD you get the path block points.