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Why we need buffered rendering ? - Printable Version

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Why we need buffered rendering ? - Merivex - 02-05-2013 06:17 AM

When I disable buffered rendering , I got full speed and 2x graphic but the sound is really choppy . But when I enable buffered rendering and disable 2x rendering , the game is slow and when enable 2x rendering , the game is 2x slow Big Grin . So I think we dont need buffered rendering because it makes the game slow . Smile


RE: Why we need buffered rendering ? - thedicemaster - 02-05-2013 08:30 AM

try some more games and you'll understand why it's needed.

some games suffer from epilepsy-inducing flashing if buffered rendering is disabled.


RE: Why we need buffered rendering ? - Henrik - 02-05-2013 08:56 AM

The PSP can render to any location in its VRAM and use as either the scanout buffer (what you see on the screen) or textures. Many games use this to implement special effects, or simply to implement 30fps (you need to show the same buffer twice). We simulate this by allocating an OpenGL FBO for every PSP framebuffer location.

PPSSPP doesn't have complete support for what the PSP can do with these buffers yet, but it's important for accuracy and will only become more so. Turning buffered rendering off is really just a speed hack that happens to work on simple games.


RE: Why we need buffered rendering ? - Carter07 - 02-05-2013 09:56 AM

(02-05-2013 06:17 AM)Merivex Wrote:  When I disable buffered rendering , I got full speed and 2x graphic but the sound is really choppy . But when I enable buffered rendering and disable 2x rendering , the game is slow and when enable 2x rendering , the game is 2x slow Big Grin . So I think we dont need buffered rendering because it makes the game slow . Smile

The speedup when you disable buffered rendering is not due to buffered rendering itself but, as Henrik said on github, it's because a bug that makes the screen render at a lower resolution putting less strain on the fragment shader.

Disabling buffered rendering, now that the bug is fixed, makes games slower than having it enabled.


RE: Why we need buffered rendering ? - Henrik - 02-05-2013 09:58 AM

Not necessarily, on some devices non-buffered rendering may be faster because you save a screen copy. That's why I've kept the option instead of always doing buffered rendering.


RE: Why we need buffered rendering ? - Carter07 - 02-05-2013 10:02 AM

(02-05-2013 09:58 AM)Henrik Wrote:  Not necessarily, on some devices non-buffered rendering may be faster because you save a screen copy. That's why I've kept the option instead of always doing buffered rendering.
Ah ok, didn't know that. Smile

Ps: shader optimizations worked, I posted some comparison screens at github. Big Grin


RE: Why we need buffered rendering ? - Merivex - 02-05-2013 10:45 AM

(02-05-2013 08:30 AM)thedicemaster Wrote:  try some more games and you'll understand why it's needed.

some games suffer from epilepsy-inducing flashing if buffered rendering is disabled.

I try dragonball evolution and its really smooth without buffered rendering . But why there are no flashing screen when only start fighting ? .. Smile so weird Idea

(02-05-2013 08:56 AM)Henrik Wrote:  PPSSPP doesn't have complete support for what the PSP can do with these buffers yet, but it's important for accuracy and will only become more so. Turning buffered rendering off is really just a speed hack that happens to work on simple games.

Thanks 4 answering this .. so in the future , will the 2X buffered rendering speed will be same like when we disable buffered rendering speed ? AND ,, do you Angel REALLY THINK Angel that PPSSPP will run FULL SPEED on SINGLE CORE 1ghz phone ? sory if this question already has been ask by other people Sad


RE: Why we need buffered rendering ? - Henrik - 02-05-2013 11:04 AM

At this point it seems clear that no, a 1Ghz phone will not run _all_ games at full speed. But I think it's likely that they will run many games fast enough, maybe with frameskipping though. We'll see.


RE: Why we need buffered rendering ? - Apology11 - 02-05-2013 05:14 PM

On my Xperia S with CM 10 it has always been faster with buffered rendering, than without.


RE: Why we need buffered rendering ? - VIRGIN KLM - 02-05-2013 05:26 PM

Well in my HTC EVO 3D when I disable buffered rendering it gets full speed but I get squished half the vertical resolution. On the games that it is known to flash it flashes (too bad I'm epileptic) and on the ones it works, you just have to deal with the squished screen.


RE: Why we need buffered rendering ? - Carter07 - 02-05-2013 05:48 PM

(02-05-2013 05:26 PM)VIRGIN KLM Wrote:  Well in my HTC EVO 3D when I disable buffered rendering it gets full speed but I get squished half the vertical resolution. On the games that it is known to flash it flashes (too bad I'm epileptic) and on the ones it works, you just have to deal with the squished screen.

If you try last build this problem is fixed.
Is it still faster without buffered rendering?


RE: Why we need buffered rendering ? - VIRGIN KLM - 02-05-2013 09:00 PM

(02-05-2013 05:48 PM)Carter07 Wrote:  If you try last build this problem is fixed.
Is it still faster without buffered rendering?

Still faster but the screen is not squished anymore (still flashes though, but it looks like it runs at something like your screen's native resolution).
Funny/Intresting thing is that it is squished with buffered rendering enabled and not squished when you have buffered rendering disabled on Digimon World Re:Digitize... (WTF?)

Buffered rendering ON: (2x internal resolution squishes it even more)
[Image: 20130204030514.jpg]
Buffered rendering OFF:
[Image: 20130205235258.jpg]


RE: Why we need buffered rendering ? - Merivex - 02-06-2013 10:38 AM

(02-05-2013 09:00 PM)VIRGIN KLM Wrote:  
(02-05-2013 05:48 PM)Carter07 Wrote:  If you try last build this problem is fixed.
Is it still faster without buffered rendering?

Still faster but the screen is not squished anymore (still flashes though, but it looks like it runs at something like your screen's native resolution).
Funny/Intresting thing is that it is squished with buffered rendering enabled and not squished when you have buffered rendering disabled on Digimon World Re:Digitize... (WTF?)

Buffered rendering ON: (2x internal resolution squishes it even more)
[Image: 20130204030514.jpg]
Buffered rendering OFF:
[Image: 20130205235258.jpg]

What is the title of this digimon game Big Grin ?


RE: Why we need buffered rendering ? - VIRGIN KLM - 02-06-2013 08:17 PM

(02-06-2013 10:38 AM)Merivex Wrote:  What is the title of this digimon game Big Grin ?
You already quoted it! Tongue


RE: Why we need buffered rendering ? - Merivex - 02-06-2013 10:20 PM

(02-06-2013 08:17 PM)VIRGIN KLM Wrote:  
(02-06-2013 10:38 AM)Merivex Wrote:  What is the title of this digimon game Big Grin ?
You already quoted it! Tongue

Big Grin ya I mean the full name Rolleyes