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PostPosted: Mon Apr 03, 2017 10:59 am 
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bogglez wrote:
Roel wrote:
bogglez wrote:
Did you toy around with the 8888 paletted mode?


I did more than toy around with it, but found that it has some disadvantages:
1. AFAIK, 8888 palettes are stored in the global palette buffer, which can accomodate only a very limited number of such palettes.
2. It doesn't render as fast as 1555.

Interesting, I thought it's only slower when used with filtering.

They need filtering to smooth out the rotation & scaling of the animations, even though the perspective is 2D.

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PostPosted: Fri Sep 22, 2017 12:38 pm 
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Roel wrote:
Hello all,

I suppose this kinda sorta belongs in this section. I would like to point your attention, if I may, to the latest new post on Senile Team's website. It foretells the announcement of a new game and does so with a small teaser image (and no it's not Age of the Beast, but some info on that is also present).

http://www.senileteam.com/index.html?do=read&id=175358

I hope you will enjoy it!


Hi, Intrepid Izzy and Age of the Beast concept art look great!

Have you guys implemented widescreen options in your Dreamcast games?

The widescreen codes have made the original Dreamcast games so much better (2D and 3D), even though the black border on VGA keeps them from being full screen.

Since you guys are starting from scratch, you can do full 720x480 in VGA mode, right?

Do you guys have enough RAM and fill rate to do some higher resolutions? I read somewhere that Omikron used anti-aliasing so it might be possible...

960x540 would allow pixel doubling on 1080p TVs and would also scale an even 4x4 on 4K screens.

If you could get to 1280x540 that would pixel double on 21:9 1080p monitors. Not sure if these ones have VGA inputs though.

I think it would really show off the Dreamcast if you can pull that off.


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PostPosted: Sat Sep 23, 2017 12:18 am 
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Thank you WingMantis!

As someone who owned a widescreen TV even back in the day when the Dreamcast was still on the shelves, its lack of widescreen support has irked me longer than most.

For 3D games, adding widescreen support is incredibly trivial. Literally a matter of changing just a single number. Thus, a greater horizontal space will be projected onto the screen, even though the resolution is unchanged.

For 2D games, that approach does not necessarily produce good results. In our case, it would produce such noticeable scaling artifacts that I don't even consider it a viable option.

Another option is letterboxing (black bars) to limit the visible area to 640x360. This has disadvantages too, of course. A significant portion of the screen will be cut off. Also, not all VGA displays offer the option to zoom in on the remaining area. Still, this is the most reliable method and it will be an available option.

An actual widescreen resolution would be ideal. However, after investigating this subject as thoroughly as various search engines would allow, I have found no evidence that anyone has ever successfully done this. KOS apparently used to have some alternative resolution settings in the code, but they were disabled because they didn't actually work (correct me if I'm wrong - I'm not an expert on KOS). Other than that, there have been some discussions about what altrernative resolutions the Dreamcast could theoretically handle, but no evidence that in practice, any of them ever worked (or were even attempted).

Nevertheless, I started experimenting with alternative resolutions myself. I managed to get various displayed on a Toshiba TV with a VGA input, however:
- 640x360 increased the refresh rate to about 85Hz, which caused problems as it's far from the standard 60Hz.
- 768x400 is too wide, and more importantly it didn't work when I tried it on another display.
- 720x416 was not properly centred, and it was not displayed with the correct aspect ratio.

Now, I created all of the above without much prior knowledge of the VGA signal, by just fiddling with the DC's video registers. That may explain why the results weren't too great. I have no idea which properties a VGA signal should have in order to be compatible with a wide selection of displays, and could not find any useful information on this subject on the net either. Nevertheless I will continue to attempt to create a reliable resolution as close to 720x400 @60Hz as possible. That would be ideal in my opinion, as it is very close to 16:9 and has a surface area that's comparable to the Dreamcast's standard 640x480, meaning it shouldn't negatively affect rendering performance.

I don't think higher resolutions, like the ones you mentioned, are worth pursuing. The Dreamcast's pixel output rate is limited, as are its signal configuration options. For example, the signal width is stored in 10 bits, making 1023 the maximum value. Note that this is not a possible horizontal resolution, though! The signal also requires space for synchronisation, so the space for actual pixels is much smaller. That's why I doubt the 960x540 you suggested is even possible.


Anyway, in conclusion: yes, there will be widescreen options. But which ones exactly, will depend on further research.

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PostPosted: Sat Sep 23, 2017 1:10 pm 
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@Roel

There is something non-conventional about the Dreamcast's VGA timing, so different TVs already don't handle it properly all the time. Mine does okay, and looks great with widescreen codes in "Full" stretch mode with small pillar boxes.

I wouldn't drop a bunch of lines just to get to a 16:9 resolution. That's tens of thousands of pixels lost. People that are still on Dreamcast and are your target market know the limitations. Get as much resolution as you can for the game.

I looked up video.h for KOS. There is a mode DM_800x608_VGA for 800x608 VGA 60Hz or DM_800x608_VGA_MB for 800x608 VGA 60Hz 4FBs (4 frame buffers?)

Has anyone ever gotten those to work?

If you did 800x608, that would be 1.2:1 though. Letterboxing to get a widescreen ratio would cause a postage stamp display because (my tv at least) fills vertically first.

There is also a generic mode DM_768x480. You would probably have to set the registers for progressive vga manually. I can actually move the Dreamcast picture side to side within the border area using in-game screen adjust. This makes the border bigger on one side. As much as I hate the border, maybe you can use the same technique to help with centering.

So 768 wide total with a border on each side so people can adjust centering as needed. You can test on different displays to see just how small you can make the border to eke out a few more pixels in width and still achieve centering. Or just do 720x480 with 34 pixel border on left and right and call it good.

In short, it really sucks anamorphic won't work for you. If everything was created as vector art from the start, could you distort to the target aspects and render sprites for each mode?

Oh and I forgot, resolutions have to be divisible by 32 so my idea of 960x540 would have to be rendered at 544 pixels and you would have to crop 4 lines to get perfect pixel doubling on a 1080p display. If only it could work! Try it lol


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PostPosted: Sun Sep 24, 2017 3:29 am 
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WingMantis wrote:
I wouldn't drop a bunch of lines just to get to a 16:9 resolution. That's tens of thousands of pixels lost. People that are still on Dreamcast and are your target market know the limitations. Get as much resolution as you can for the game.


I already am getting as much resolution as I realistically can, which is 640x480. 640x360 is an option. ;)


WingMantis wrote:
If you did 800x608, that would be 1.2:1 though. Letterboxing to get a widescreen ratio would cause a postage stamp display because (my tv at least) fills vertically first.


Actually it would be closer to 1.3:1, or 4:3. And it would work fine on a display that's smart enough to allow zooming in VGA mode (mine doesn't do that either though). That is... if it would actually work. I've looked it up too, and in video.c you'll find that this mode is disabled, and preceded by the following comment:
/* 800x608 NTSC 60Hz (VGA) [BROKEN!] */

I'll take a look at the other modes, though, when I have the time.


WingMantis wrote:
In short, it really sucks anamorphic won't work for you. If everything was created as vector art from the start, could you distort to the target aspects and render sprites for each mode?


Don't need vectors for that. The graphics are already scaled down so that could just as well be done with a different aspect ratio. But it would be pointless because it wouldn't work for any graphics that need to be rotated.

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PostPosted: Tue Sep 26, 2017 1:48 am 
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Interrupting the discussion about widescreen options for some big news! Launching on KickStarter tomorrow! :D

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PostPosted: Tue Sep 26, 2017 3:52 pm 
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I thought it was going to be fully self-funded. Anyway, I'll wait to read the details in the campaign.

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