@Michel Bujardet : This is exactly what I did in the “normal” mode in my test project:
[code]dim p As new Picture(w * 2, h * 2)
mainCanvas.Backdrop = p[/code]
But the result is that the picture is drawed in non-retina to the canvas, so in double size.
Note how I use g.ScaleX to get the actual scale of the screen.
In my example, in non Retina, since ScaleX would be 1, the picture would be at the correct scale.
[quote=381438:@Michel Bujardet]What you also need is to detect if you are in Retina mode to make the picture with twice as much pixels on each side.
[/quote]
Actually, you can call TrueWindow.BitmapForCaching(width,height) and itll do all that work for you automatically, depending on the screen the window is on.
Yes … ScaleX and Y are 2 in my case. So for my device Width * 2 is the correct size.
@Greg O’Lone : Thanks, this is the most elegant way, with best render result.
I will start implementing this concept now.
Demo project is updated.
Here is a stripped demo project just with the bitmap solution.
http://downloads.revolversoftware.com/dev/canvas_bitmap.zip
Maybe it is helpful for somebody.
That is what I get for not reading thoroughly enough release notes 
I did not realize that existed. It is definitely easier. Thank you Greg.