Ideal display settings for Amiga with scanlines, and possible new look for new FS-UAE

[FrodeSolheim]

When you use a scanline filter (or a similar effect), you'll only get a "perfect" result if you scale the resulting picture in integer steps (1x, 2x, 3x, etc). The "scanlines" need to correspond exactly with the LCD pixels. Here's an illustration of what happens when the scanlines line up with LCD pixel row (left image) and when scaling causes the scanlines to not line up with LCD pixel rows (right image). You can see a wave pattern in the right image:



So using scanlines should ideally be combined with using a fixed zoom level / viewport in FS-UAE which ensures correct scaling.

Having 1920x1080 as native LCD resolution is especially practical. 1080 divided by two is 540, which is a nice vertical resolution for Amiga, because this allows for a 640x512 picture (PAL) with some overscan, scaled exactly 2x in height. A good choice for FS-UAE viewport is 672x540, which is becomes 1344x1080 when scaled 2x. When centered on the 1920x1080 display, this leaves 286 pixels on either side (unless the image is streched horizontally). Alternatively, to show some more overscan, 704x540 (1408x1080) is also a nice size, or even 720x540 (1440x1080).

The extra free areas on the left and right side could be used to display more information. Here is a mockup (with LEDs borrows from nexusle's theme) for a 16:9 theme which exploits the free areas to show LEDS (drive access, status, warnings), performance graphs (audio fill buffer, frame rate), and in net play mode, also information about players:



The scanlines in the above image are perfectly aligned, the screen size here is 960x540, and the Amiga viewport is 672x540 -so the Amiga display is shown 1:1 here. The black border surrounding the game screen is part of the Amiga display and not the FS-UAE theme (it just happens to be a black border in this game).

(NB: not all features in the mockup are currently possible with the existing theme infrastructure. Also, I'm not currently suggesting that *this mockup* should be the default, but that the default FS-UAE video settings could move in this direction).

[nexusle]

*** Deleted ***

Very nice! This is such a common problem on almost every emulator out there. Nice to see yet again your quest for perfection is benefiting us all! I hope you keep your passion going as I will certainly be doing as much as I can to help you.

[nexusle]

So is there a ability to implement, that themes can have the size of the native resolution?

Sidenote: The real Amiga Power LED have 3 states. OFF, ON and HALF. Is there a ability to show this in FS-UAE? Some source code for this?

[spajdr]

this is pure scanline , just awesome.

[FrodeSolheim]

Originally Posted by nexusle

So is there a ability to implement, that themes can have the size of the native resolution?

Hi, themes are always stretched to the native resolution. So if you create an overlay of 1680x1050, and use this on a 1680x1050 monitor, the image will be displayed 1:1 without scaling. But it is true that the other custom overlays (LEDs) are scaled as if the display is 1920x1080. You can specify their position to suit the 1680x1050 theme by converting the coordinates, but there's no way to override the size.

I'll do something about it, perhaps a theme option to tell FS-UAE what size the theme is designed for.

Originally Posted by nexusle

Sidenote: The real Amiga Power LED have 3 states. OFF, ON and HALF. Is there a ability to show this in FS-UAE? Some source code for this?

I'll have a look at it. Any suggestions for software/games which affects the power led (audio filter) for testing?

[nexusle]

*** Deleted ***

[FrodeSolheim]

I think it would be more correct to say that the power LED only has two states: "On" and "Half"? ("Off" == FS-UAE not running). So the theme could just render a half-bright LED on the background -which the ON-led will cover when active.

But due to transparency effects and pixel-rounding in OpenGL, it might still be slighty better to have a separate LED overlay for the dimmed light...

I could also, while at it, implement support for alternative LEDs when DF0..DF3 and HD have *write* operations..

[FrodeSolheim]

I have created a new thread to discuss new theme optons, and I have also just now released 2.1.21 which has more flexible theming options.
New thread is here: http://eab.abime.net/showthread.php?t=67567

(The improved theme support includes better support for custom resolutions, multiple states for LEDs and replacing custom_x with "real names" and new overlay types).

Please discuss the new general theme features (and request new theme features?) in the new thread, and not in this one

[John Pillow]

Originally Posted by FrodeSolheim

using scanlines should ideally be combined with using a fixed zoom level / viewport in FS-UAE which ensures correct scaling.

Having 1920x1080 as native LCD resolution is especially practical. 1080 divided by two is 540, which is a nice vertical resolution for Amiga, because this allows for a 640x512 picture (PAL) with some overscan, scaled exactly 2x in height. A good choice for FS-UAE viewport is 672x540, which is becomes 1344x1080 when scaled 2x. When centered on the 1920x1080 display, this leaves 286 pixels on either side (unless the image is streched horizontally). Alternatively, to show some more overscan, 704x540 (1408x1080) is also a nice size, or even 720x540 (1440x1080).

Hi Frode, having a MacBook Pro with a 1440x900 resolution, what fixed zoom level and viewport would you recommend?

Right now i'm only using the following:

fullscreen = 1
zoom = full
keep_aspect = 1
shader = crt
low_resolution = 1
line_doubling = 0

Cheers!

[John Pillow]

Gentle bump :-)

Some tests with Blood Money:

Intro: http://imageshack.us/photo/my-images/10/22086595.jpg/
Intro: http://imageshack.us/photo/my-images/541/68322421.jpg/
Menu: http://imageshack.us/photo/my-images/541/68322421.jpg/
Gameplay: http://imageshack.us/photo/my-images/198/96423733.jpg/

Cheers

[John Pillow]

Hi there,
do not want to sound boring, and this is probably due to me being new to FS-UAE or shaders in general, but i noticed that while games look and feel like the "good old days", on Workbench (and/or on most Cracktros) fonts seem to be "eaten away", an example:

Workbench 1.3: http://imageshack.us/photo/my-images/33/wb01k.jpg/
Workbench 1.3: http://imageshack.us/photo/my-images/18/wb02j.jpg/
IK+: http://imageshack.us/photo/my-images/855/ikplus01.jpg/
IK+: http://imageshack.us/photo/my-images/14/ikplus02.jpg/

Do you know a possible solution or trick?

Cheerio

[Retro-Nerd]

It seems you use lores. This doesn't work properly with 640x256 PAL Hires WB resolutions for fonts.

[John Pillow]

Thanks!

With low_resolution = 0 and line_doubling = 1 Workbench looks great:

http://imageshack.us/photo/my-images/832/wb1301.jpg/

While for games i'll keep a separate config with low_resolution = 1 and line_doubling = 0

Cheers

[TCD]

You'll have the same effect for text-adventures or in general hi-res games with text.

[John Pillow]

Thanks,
luckily all games i'm playing atm seems low-res (Speedball 2, Blood Money, X-Out, Gods, Shufflepuck Cafe, E-Motion, IK+, Stunt Car Racer, Wizball, Xenon 2, Rick Dangerous, Axel's Magic Hammer).

Cheers

[TEOL]

Is it possible to add a small curve to the edges of all the lines we have in our now perfect for LCD in density and thickness straight existing scanlines into upwards and downwards curved ones with a straight one in the middle to give them the psychedelic look of a real CRT only with our own thinner thickness from these so it looks real but a lot better than the real thing.

Here is the real scanlines effect on SWIV an actual AMIGA game. The scanlines are thick probably because it's a small size CRT but I would imagine a bigger CRT would look like the ones we have here in spacing instead of massive but I think the video shows of the curves of a real scanlines very well which is what we want for following to make the real effect on our own thinner lines if we can archive making it.

[ Show youtube player ]

I'm not complaining but I feel straight ones look fake and not right but at the same time I think the FS-UAE ones are the best straight ones out there so I'm 75/25 the 75 being good and the 25 being the bad but I would like them 100% if we got some curves into those existing lines.

[Retro-Nerd]

What scanlines? All i can see are distortions due to filming a CRT screen with a camera. Looks more like a crappy Composite Cinch cable was used. A proper RGB cable would show us decent scanlines.

Real CRT scanlines:

[ajk]

Scanlines should be the same regardless of the cable, they are a feature of the display rather than the Amiga. Still, that particular video is so low resolution that scanlines wouldn't show up in any case. Those thick red-green arcs are some sort of moire effect like Retro-Nerd already mentioned. Here are some photos of actual scanlines from another thread here on EAB. They are as straight as the display is.

[Retro-Nerd]

Well, with an antenna cable you won't see the scanlines unless you put your nose on the TV. Best connection for shiny scanlines is RGB, as shown in Dukes and the Sonic screenshot above.