Improved scanline renderer in FS-UAE

[mr_a500]

I noticed a problem with the replaced ("old style") scanlines - in 2.1.29:



I also noticed this when I attempted to use "old style" scanline code (from 2.1.19) in 2.1.27 - but I just assumed I screwed something up or missed something.

[Goingdown]

Originally Posted by spajdr

Yo matey, what exact shader you trying? i dont have any problem with my Intel HD 3000.

Attach file fs-uae.log.txt from FS-UAE\Logs directory

Tried scanlines-nonlinear and scanlines-classic. Both will give same error message. All other shaders I tried are working.

[FrodeSolheim]

Originally Posted by spajdr

By the way, is it possible to combine two shaders into one file, like scanline classic + curvature?

Yes, in most cases. But it might require some knowledge of how the shader system works to get optimal results...

Originally Posted by Goingdown

Tried scanlines-nonlinear and scanlines-classic. Both will give same error message. All other shaders I tried are working.

Thanks for helping debugging the problem (IRC). Fixes will be included in .30 (Shaders did not follow the specification to the letter, worked with some OpenGL drivers).

Originally Posted by mr_a500

I noticed a problem with the replaced ("old style") scanlines - in 2.1.29: I also noticed this when I attempted to use "old style" scanline code (from 2.1.19) in 2.1.22 - but I just assumed I screwed something up or missed something.

I haven't seen anything like that. But when I think of it, the scanline implemention may not work properly with (video format) rgb565. Is that what you're running? Does it work with video format rgba or bgra?

[mr_a500]

Originally Posted by FrodeSolheim

I haven't seen anything like that. But when I think of it, the scanline implemention may not work properly with (video format) rgb565. Is that what you're running? Does it work with video format rgba or bgra?

I use default video format. The problem is same with rgba. The rgb565 was screwed up (remember corrupted screenshot in other thread) before, but now the screen remains completely black. (...but I don't care about that because default video format was fine before)

Something you changed when making the scanlines as shaders is causing this problem. (It's not in scanlines.c because as I said, when using the one from 2.1.19 instead - the problem is still there.)

[FrodeSolheim]

OK, what was the last version where scanlines worked correctly for you? 2.1.19 does not work I gather, does for example 2.1.18?

[spajdr]

Strange, all shaders works for me. I just have latest intel driver.

[mr_a500]

2.1.19 was the last version with the old scanlines - working fine. 2.1.21 - 2.1.27 have the new scanlines - working fine. 2.1.27(u?) has the new scanlines re-implemented as shader. That's the first version with the problem.

[FrodeSolheim]

@mr_a500. There's a couple of lines missing (for PPC), try this patch

diff --git a/libfsemu/src/emu/scanlines.c b/libfsemu/src/emu/scanlines.c
index d7deb36..64849d6 100644
--- a/libfsemu/src/emu/scanlines.c
+++ b/libfsemu/src/emu/scanlines.c
@@ -37,6 +37,10 @@ void fs_emu_render_scanlines(uint8_t* out, fs_emu_video_buffer *buffer,
                 continue;
             }
             for (int x = 0; x < cw; x++) {
+#ifdef __BIG_ENDIAN__
+                src ++;
+                dst ++;
+#endif
                 *dst++ = (*src++ * light_ia) / 256 + scanline_light;
                 *dst++ = (*src++ * light_ia) / 256 + scanline_light;
                 *dst++ = (*src++ * light_ia) / 256 + scanline_light;

[spajdr]

Frode : i wonder, can you add this shader to be compatible with fs-uae?
http://www.sendspace.com/file/p8037b

[FrodeSolheim]

The shader language is GLSL, so the shader could perhaps work with FS-UAE with small modifications. It isn't enough that the language is OpenGL Shading Language, shaders must also know how to get the Amiga video texture (and other information) from the emulator.

FS-UAE loads shaders following the "XML Shader Format 1.1" (http://gitorious.org/bsnes/pages/XmlShaderFormat). So someone would have to rewrite the shader slightly.

(Hmm, looking at the shader code, it uses two uniforms in addition to the video texture, color_texture_sz, color_texture_pow2_sz (vec2), and it is not immediately obvious what these are. FS-UAE do not provide such vec2s to shaders).

[spajdr]

No problem thanks for trying

[Retro-Nerd]

Another nice example for non-linear scanlines.

[FrodeSolheim]

@Retro-Nerd, Yes, though you can see a slightly annoying "wave pattern" in the solid color areas. See this thread on how to fix that: http://eab.abime.net/showthread.php?t=67535.

[Retro-Nerd]

Thanks for the custom theme settings. Looks really good now.

[TEOL]

After looking at this thread since I was watching a video at the same time I nicked these real scanlines from a youtube video where somebody recorded a video of an old game on his actual CRT TV.

So now we have a picture of some real scanlines maybe somebody can work on making a legit looking ones for our AMIGA emulator now and be the first emulator ever to have legit looking scanlines in the program?

As you can see by the picture the legit style scanlines have large spaces in between each set and look diagonal half circle style.

The real half circle scanlines also have verical scanlines going through them which are the Composite/RGB/RF/Component scanlines which come from the systems to make up the picture.

So basiclly TV scanlines are oval rather than horizontal and Console/Computer scanlines are vertical both together making a real scanlines picture which it's what I gather from the picture.

These oval scanlines look like a vortex into another dimension but they are at the same time actual CRT TV set ones as well. What retro beauty.

I've now since last Janurary become a regular user of FS-UAE and WinUAE unless if I'm pratting about in Workbench GUI as my WinUAE hard drive files didn't want to work in it is an after thought as far as playing both disk and WHD games is concerned now so I'm a complete FS-UAE backer all the way.

[FrodeSolheim]

Originally Posted by TEOL

So basiclly TV scanlines are oval rather than horizontal and Console/Computer scanlines are vertical both together making a real scanlines picture which it's what I gather from the picture.

I'm afraid the "circular wave pattern" in the photo does not represent real scanlines on CRTs/TVs. This pattern shows up in the digital picture because the picture has too low resolution to represent the complex/real pattern on the TV screen. This is an aliasing effect (see Moiré_pattern), and the person taking that picture would not see that pattern when looking at the real TV screen.

So this photo should not be used as basis for creating a scanline shader

Btw, you'll also see similar problems in TV broadcasts if a person in a TV studio has a sweater with a detailed checkered pattern, for instance.