theoryno3 / bizhawk

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seriously consider gfx debugging tools update timing #96

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
seriously consider gfx debugging tools update timing. 

when we get proper interactive debugging, the gfx tools MUST reflect current 
contents of vram.

from user perspective, sometimes you want gfx tools to reflect PREVIOUS 
contents of vram (i.e. what was used to generate the frame that just got 
output). 

but, keep in mind, we tend to break the frame at the beginning of vblank, so 
the game is almost surely going to set values for the next frame's rendering 
too late for us to catch it. so if we capture the gfx state before, and then 
emulate a frame, it wont be faithful.

finally, remember, we have scanline controls for some gfx tools. it may be best 
to normalize the non-scanlined behaviour with the scanlined behaviour in some 
kind of clear way, by defining non-scanlined behaviour to occur at a certain 
scanline, or understanding when it happens in the frame.

Original issue reported on code.google.com by zero...@zeromus.org on 4 Oct 2012 at 10:21

GoogleCodeExporter commented 9 years ago
Here is the current state of things in GB and GBA:

Emulation frame timing: Frame end roughly coincides with the end of the visible 
frame, which roughly coincides with vblank interrupt signalling.

GFX tool timing update has three options: end of frame, manual, and scanline 
based.  The scanline control is arranged so that the numbers appear in 
chronological order.  Manual produces end of frame timing, but only when 
clicked.

The more I think about it, the more I think it isn't necessarily the greatest 
thing in the world.  End of frame is duplicating a particular scanline 
selection, and I'm struggling to imagine a real usage case for manual.  But, 
that's what it is for now.

Original comment by goyu...@gmail.com on 1 Dec 2012 at 7:43

GoogleCodeExporter commented 9 years ago

Original comment by zero...@zeromus.org on 9 Jun 2014 at 3:51

GoogleCodeExporter commented 9 years ago

Original comment by zero...@zeromus.org on 9 Jun 2014 at 4:04