Re: [AD] problem with Chris' X primitives patch

[Chris <kcat@xxxxxxxxxx>]

Peter Wang wrote:
> Chris wrote:
> > The attached patch fixes the exspline problem.
>
> Great.  It appears to have solved exjoy as well.

There's a small potential issue I just caught. If you use XOR mode then 
switch to an unsupported mode (leaving XPutImage to do the copy) when in 
matching depths, a similar issue will occur. The working patch should 
fix that.

> > But it seems I've possibly stumbled across a more general problem. Is 
> > gfx_driver->drawing_mode called when a new video mode is set, or is 
> > the drawing mode reset when a mode is changed? 
>
> Neither, it seems.

Ok. Well, the current working patch also calls gfx_driver->drawing_mode 
when setting a mode, so the drawing mode is retained when switching 
video modes.

Hmm.. after testing this latest patch, it seems there's a problem. Using 
the test program, I switched on XOR mode drawing and did the putpixel 
test in three depths: 8, 16, and 32 (matching). The results are problematic.

* In 8-bit, it acts as if the drawing mode is completely ignored.. the 
pixels are the original colors. I don't see anything in my patch that 
would cause one mis-matched depth to behave different from another 
mis-matched depth.
* In 16-bit, the pixels are inversed (corectly), although the text 
displaying the putpixel count is /not/ inversed. I don't ever remember 
seeing the text invert before, so I would assume this is correct behavior.
* In 32-bit (the same as my desktop, so it's using the X routines), the 
pixels are inversed as well as the text (white text with a black 
background).

Now, regardless of which is right (between 16 and 32-bit), there's a 
bug. Either the default font rendering functions for memory bitmaps is 
improperly ignoring the drawing mode (meaning 32-bit is right), or the 
text routines aren't temporarilly setting a solid mode in case it falls 
back on primitives to draw the text (meaning 16-bit is right).

In either case, I'm completely baffled by 8-bit's behavior.

- Kitty Cat