"Vertical Retrace" (Series 60)

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Tue, 2003-04-08 18:23
zeep
Joined: 2003-04-03
 Forum posts: 31
Hi!

I am looking for a way to sync my graphics drawing to the refresh of the screen.
Currently I am not incorporating Direct Screen Access but am already getting about 60fps. The problem with this is that when the whole screen is moving (eg. scrolling) ugly tearing effects are visible.
My guess is the DMA controller used to transfer memory to the screen is just much too slow. At least in the n-gage specs it is stated that just 30 fps are possible.

I am now looking for a way to sync my drawing to the screen refresh. Is there a way to do this?

tnx, zeep

zeep

Wed, 2003-04-09 02:08
ouseka
Joined: 2003-04-01
 Forum posts: 37
"Vertical Retrace" (Series 60)
Hi, thanx for your help in the other topic Smiley

For this question, I think you can find a way to access screen memory directly in the example `9210game' at www.symbian.com Smiley

But during my coding in this way, I met some strange matter...

Regards,
ouseka

ouseka

 
Wed, 2003-04-09 12:18
nanard
Joined: 2003-04-01
 Forum posts: 9
"Vertical Retrace" (Series 60)
It seems that the Screen Refresh is 64Hz and that using Direct screen access on series 60 platform as explained in the "direct_screen_access.pdf" file from Symbian automatically sync to that. But sometimes sync doesnt seems to be done properly. Maybe should we try to stop interrupts or block process switching during bitblt Huh
 
Wed, 2003-04-09 17:25
zeep
Joined: 2003-04-03
 Forum posts: 31
"Vertical Retrace" (Series 60)
Quote from: nanard
It seems that the Screen Refresh is 64Hz and that using Direct screen access on series 60 platform as explained in the "direct_screen_access.pdf" file from Symbian automatically sync to that. But sometimes sync doesnt seems to be done properly. Maybe should we try to stop interrupts or block process switching during bitblt Huh

I don't think the screen refresh is 64hz. The system timer of Series 60 devices ticks at 64hz. This probably explains the usage of this value in the example (which btw is tearing HORRIBLY on my phone).

As it's stated in the n-gage faq:
Code:
2.4 How large is the display? What color depth does it provide? How many frames per second can it display?
The display is 176 x 208 pixels in size. It supports 4,096 colors (12 bits). The maximum frame rate is 30 frames per second.

I think 30fps is pretty poor for a games device (GBA does ~50fps).

Your suggestion to block interrupts seems the way to go. Do you know how to accomplish that?

zeep

 
Sun, 2003-10-05 01:16
ghoom
Joined: 2003-10-05
 Forum posts: 1
"Vertical Retrace" (Series 60)
GBA -> 59.727 Hz
But gba is a real console
 
Sun, 2003-10-05 10:26
pawel
Joined: 2003-05-27
 Forum posts: 363
"Vertical Retrace" (Series 60)
Hi,

As far as I know, there is no way you can obtain a vertical retrace notification on any of the current Symbian devices. This is based on what I know about hardware interfaces and the devices drivers for the display controllers.

I really would like to be proven wrong  Cheezy .

Regarding the interrupts, stopping them is an questionable idea really - it would make the whole phone side ( the custom OS side ) probably crash. You could not do this anyway without writing kernel-side code ( a device driver ).


Cheers,
Pawel
 
Sun, 2003-10-05 13:51
Anonymous (not verified)
Forum posts: 2043
"Vertical Retrace" (Series 60)
Quote from: pawel
Hi,

As far as I know, there is no way you can obtain a vertical retrace notification on any of the current Symbian devices. This is based on what I know about hardware interfaces and the devices drivers for the display controllers.

I really would like to be proven wrong  Cheezy .

Regarding the interrupts, stopping them is an questionable idea really - it would make the whole phone side ( the custom OS side ) probably crash. You could not do this anyway without writing kernel-side code ( a device driver ).


Cheers,
Pawel
 
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