Plus42 Equations, Preview Release

[Thomas Okken]

It was pointed out to me that Free42 3.0.11 for Windows is a lot slower than 3.0.10 when running display-intensive programs.

This is because of how the display is drawn on the screen: 3.0.10 did this using GDI, BitBlt() to be precise, but 3.0.11 uses GDI+, in order to support non-integral display scales. And the GDI+ bitmap render apparently takes twice as long.

There is actually a deeper issue with Free42 and Plus42 for Windows: they paint the display immediately, whenever the core updates it. This is really inefficient, because the human eye can't keep up with that kind of frame rate anyway, and it makes more sense to put a limit on the number of repaint operations per second, and allow program execution to hog the CPU the rest of the time. Which is what the Android, iOS, and MacOS versions do as well.

I made this change in Free42 and verified that, instead of being 2x slower than 3.0.10, it is now 5x faster, despite still using GDI+.

The improved display update code for Windows will be in Free42 3.0.12 and Plus42 1.0.1. In addition, I uploaded Plus42 test builds here.

It looks like the Linux version may benefit from this type of surgery as well. I'll look into that tomorrow.