| Time |
Nickname |
Message |
|
04:11
🔗
|
SketchCow |
I'll be right over |
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04:11
🔗
|
SketchCow |
<airsiren> |
|
04:14
🔗
|
db48x |
heh |
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04:19
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taisel has joined #jsmess |
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05:28
🔗
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taisel has quit IRC (Quit: Leaving) |
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05:33
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icculus has joined #jsmess |
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05:34
🔗
|
icculus |
hello, Jason Scott sent me. |
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05:35
🔗
|
bai |
oh man, bringing in the big guns :D |
|
05:36
🔗
|
bai |
welcome |
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05:37
🔗
|
icculus |
hi. :) |
|
05:38
🔗
|
bai |
so how much do you know about what's going on in here? I'm more than happy to get you up to speed |
|
05:38
🔗
|
icculus |
Jason said there was some sort of MAME-vs-Emscripten issue, and I should come get technical details from the fine folk in this channel. |
|
05:38
🔗
|
icculus |
Something about it using 100% CPU for no good reason |
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05:39
🔗
|
bai |
yeah, so it's been working pretty solid for a while now, but we want it faster and yeah, less cpu burning when idle |
|
05:39
🔗
|
bai |
MAME is built using the standard game loop architecture, a tight loop executing as fast as possible, with some calls to a sleep wrapper which calls the appropriate sleep function for the platform |
|
05:40
🔗
|
bai |
to control timing of machine chips and ultimately frame output |
|
05:41
🔗
|
bai |
but with emscripten...well, how much do you know about that whole thing, specifically its async handler? |
|
05:41
🔗
|
icculus |
I’ve gotten a few games running with Emscripten: https://icculus.org/ut99-emscripten/ and some stuff on playonjump.com |
|
05:41
🔗
|
icculus |
So I’m pretty familiar |
|
05:43
🔗
|
bai |
cool, yeah I figured. so, we've modified MAME's main game loop to use emscripten_set_main_loop, and as it is now we basically have it hardcoded to assume 60fps, and to advance the machine's internal emulation clock by the appopriate number of ticks |
|
05:44
🔗
|
bai |
https://github.com/mamedev/mame/blob/master/src/emu/machine.cpp#L1321-L1360 |
|
05:45
🔗
|
bai |
using that code, the cpu profile looks like this https://i.imgur.com/80HgKvk.png |
|
05:46
🔗
|
bai |
because scheduler->timeslice(); |
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05:46
🔗
|
bai |
oops |
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05:46
🔗
|
bai |
because scheduler->timeslice() is where all the sleep() magic happens for timing |
|
05:47
🔗
|
bai |
and on the emscripten platform it's just doing the naive while (Date.now() < t) {} style sleep implementation |
|
05:47
🔗
|
icculus |
So this is just burning the entire ~16 milliseconds, returning so the framebuffer can swap, and then starting again, 60 times a second |
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05:47
🔗
|
bai |
yup |
|
05:48
🔗
|
icculus |
This should be solvable, then. |
|
05:48
🔗
|
bai |
now, I've got an experimental branch which tries to handle it a bit more intelligently - if the system is asked to sleep() for longer than the amount of time left in this frame, it basically stops processing until the next emcripten main loop call |
|
05:49
🔗
|
bai |
this ends up looking like this https://i.imgur.com/YEEbT9b.png - much cleaner |
|
05:49
🔗
|
bai |
but it introduces some timing issues |
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05:50
🔗
|
icculus |
How long are these sleeps intended to be, generally? |
|
05:50
🔗
|
bai |
because I did it in a pretty hacky way while trying to work through some theories, and my feeble brain turns to mush when I try to consider the delicate timing balance of a system like this |
|
05:50
🔗
|
icculus |
are they…five milliseconds or like 50 milliseconds? |
|
05:51
🔗
|
bai |
let me refresh myself on the code. I think the mame functions themselves are in something insane like picoseconds |
|
05:56
🔗
|
DFJustin |
attoseconds |
|
05:59
🔗
|
bai |
that's right |
|
06:00
🔗
|
bai |
sorry dealing with space issues on my vm. I guess a stock ubuntu install chews right through 12 now |
|
06:00
🔗
|
bai |
12 gigs* |
|
06:02
🔗
|
icculus |
no worries |
|
06:03
🔗
|
icculus |
the more direct question: where do I build this from? Is it on mamedev/mame, or is this a separate fork elsewhere? |
|
06:03
🔗
|
bai |
it's all part of the official release now, except for my hacks |
|
06:04
🔗
|
icculus |
ok, I’m going to poke at it in the morning, then, and hopefully I’ll make some progress. |
|
06:04
🔗
|
bai |
sweet |
|
06:04
🔗
|
bai |
I'll dig up my own patches by then to give you a starting point of where in the codebase you'll want to poke things |
|
06:05
🔗
|
icculus |
for now, though, I’m going to sleep. I’ll idle in this channel though, in case anyone wants me to hear any details. |
|
06:05
🔗
|
icculus |
ok, that’s great, thank you! |
|
06:05
🔗
|
bai |
sounds good, looking forward to seeing what we can come up with |
|
06:05
🔗
|
bai |
been a long-standing issue |
|
06:45
🔗
|
Vito` |
Haha |
|
06:45
🔗
|
Vito` |
I think my internet is a closed loop now |
|
06:46
🔗
|
Vito` |
I need new circles, everyone I know ends up in here |
|
06:54
🔗
|
bai |
all roads lead to #jsmess |
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07:24
🔗
|
SketchCow |
I never stop |
|
07:24
🔗
|
SketchCow |
You said we needed people, I got people |
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07:26
🔗
|
SketchCow |
icculus: Bai is the main person who was trying this but he got super busy because his company needs him |
|
07:27
🔗
|
SketchCow |
icculus: DFJustin has worked in MAME a long time, he can help. A pile of other people are here and can help as well: azakai is the maintainer of Emscripten, db48x has done a bunch of work with all this, and Vito` and devesine also have done massive work in the past. |
|
12:46
🔗
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icculus has quit IRC (icculus) |
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13:30
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icculus has joined #jsmess |
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15:15
🔗
|
icculus |
omg, this thing takes forever to build. Emulate less hardware next time! lol |
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15:56
🔗
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icculus has quit IRC (icculus) |
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15:57
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icculus has joined #jsmess |
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15:57
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icculus has quit IRC (Client Quit) |
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15:57
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icculus has joined #jsmess |
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15:58
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icculus has quit IRC (Client Quit) |
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16:58
🔗
|
SketchCow |
How's it going for you? |
|
17:05
🔗
|
db48x |
:) |
|
17:07
🔗
|
SketchCow |
On my side, I've been ripping CD-ROMs all morning. |
|
17:07
🔗
|
SketchCow |
Someone sent me 500 |
|
17:08
🔗
|
db48x |
nice |
|
17:32
🔗
|
SketchCow |
Yeah, it's going to kick ass to get these up |
|
17:33
🔗
|
SketchCow |
Then it's time to sort them, and maybe consider breaking some out into emulated chunks. |
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17:49
🔗
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icculus has joined #jsmess |
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18:47
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icculus_ has joined #jsmess |
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18:49
🔗
|
SketchCow |
By the way, the latest podcast episode is about Emulation |
|
18:49
🔗
|
SketchCow |
(and a demo I like that's an emulator) |
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18:50
🔗
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icculus has quit IRC (Read error: Operation timed out) |
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18:50
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icculus_ is now known as icculus |
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18:51
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icculus has quit IRC (Client Quit) |
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19:31
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icculus has joined #jsmess |
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19:31
🔗
|
icculus |
Uh, is it normal to not be able to link this in 16 gigabytes of RAM? https://gist.github.com/rcgordon/d57e1e3fb504cb698edb091543bda27b |
|
19:31
🔗
|
icculus |
This was just a git clone, then CC=emcc make |
|
19:31
🔗
|
icculus |
which might totally be the wrong way to do this |
|
19:33
🔗
|
bai |
icculus: oh, yeah you generally don't want to do a full build of all systems |
|
19:34
🔗
|
bai |
we normally do a build per system |
|
19:34
🔗
|
icculus |
oh |
|
19:38
🔗
|
bai |
I think what you want is something like "emmake make SOURCES=src/mame/drivers/pacman.cpp" |
|
19:40
🔗
|
icculus |
yeah, that builds much quicker. :) |
|
19:49
🔗
|
bai |
finding the right source file for the system you're targeting is a bit of black magic, mame has a -listsource file but it's....well....it's just dumb and wrong half the time :D |
|
19:49
🔗
|
bai |
eg, "mame -listsource pacman" tells you the source is "pacman.c" when really it's "src/mame/drivers/pacman.cpp" |
|
19:50
🔗
|
bai |
(plus you need a native build to do it, too) |
|
19:55
🔗
|
db48x |
yea, I really want better automation there |
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20:07
🔗
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icculus has quit IRC (icculus) |
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20:08
🔗
|
SketchCow |
Oops, h's gone |
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20:08
🔗
|
SketchCow |
we killed him |
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20:08
🔗
|
SketchCow |
this seems promising |
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20:31
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azakai has quit IRC (Quit: Ex-Chat) |
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21:57
🔗
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DFJustin |
-listsource should always be correct although it doesn't specify src/mame/drivers/ |
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21:57
🔗
|
DFJustin |
if there's a mismatch, the mame in your path may be out of date |
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22:07
🔗
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azakai has joined #jsmess |
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23:07
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icculus has joined #jsmess |
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23:11
🔗
|
bai |
hmm, I suppose that's not impossible, I might have a system-installed binary version |
|
23:12
🔗
|
bai |
wonder when they switched from .c to .cpp |
|
23:13
🔗
|
* |
db48x recommends running "type mame" |
|
23:15
🔗
|
bai |
yeah, it's definitely a system install, just not sure how old we're talking :D |
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23:22
🔗
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icculus has quit IRC (icculus) |