Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

crt-pi-vertical.glslp issue / horizontal lines only



  • I was testing some shaders and I wanted to have those nice vertical lines for authentic game feeling on shoot em ups like 1941, 1944, 19XX etc...
    I access the retroarch menu (Quick menu -> Shaders -> Load Shader Preset) and there I load crt-pi-vertical.glslp
    Now it suppose to show vertical scan-lines but I get only horizontal ones. Same happens with the crt-pi-curvature-vertical.glslp

    Running a RPi 3
    ES v2.4.1RP
    Retroarch v1.6.0
    RetroPie Script 4.2.12

    Can anyone out there give this a quick try and check if the same thing happens?



  • No one? Really?
    Nobody can spare 5min and do a quick test?



  • Hi @FlyingTomahawk

    Firstly, Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first . Not only have you not completed the information requested, but also you have bumped a post unnecessarily. Just because no one answered you, does not mean you are being ignored, we all have lives too.

    The crt-pi-vertical shader isn't doing what you expected, but it doesn't look like it has ever done as it was intended to (someone has copied and pasted crt-pi and changed 2 instances of x to y). I have downloaded the latest version of the shader files from the LibRetro git and even installing on a PC running RetroArch, it produces horizontal scanlines. If you want vertical ones, I don't know if there is a shader that does this already, but it wasn't obvious in their git repository.



  • OK, I've done some more diagnostics and it does work but the rom seems to need to be recognised by something as a vertical resolution.

    I loaded APB into lr-mame2003 and the scanlines are vertical, however if I load something like Track & Field the same shader gives horizontal scanlines.



  • The vertical variants of crt-pi aren't responsible for producing vertical scanlines. They are for correcting the shadow mask emulation.

    See this page for an explanation of the problem.

    If you're not getting vertical scanlines there is something else wrong with your setup.



  • @simonster

    Please don't do that. Don't talk to me like I am a complete noob or first time poster.

    I did my research before posting, I didn't ask "why" it is not working or "how to fix it" I just simply wanted to know if this is happening only to me or also to others. I didn't feel it was necessary to write my PSU specs or what emulator not for a simple shader "test".
    And after 50+ views I thought I ask if really no one could spare those 5 minutes to test and confirm.
    I am here every day and I see how many users are online and it seems to me that there are plenty of people that have a bit time to spare.

    That said, I thank you for taking some of your precious time to test this and confirm that the shader doesn't produce vertical lines as is.
    It is a bit confusing though because if crt-pi creates horizontal lines I would automatically think that crt-pi-vertical would create, well, vertical lines on a regular screen setup but that isn't the case.

    Not sure how someone would create vertical lines though I just simply took ruckages overlays, edited and flipped them to simulate those vertical lines and it seems to work quite well.


  • Global Moderator

    @flyingtomahawk

    didn't feel it was necessary to write my PSU specs or what emulator not for a simple shader

    actually emulator is totally relevant. the emulator itself tells libretro/retroarch that the game is rotated (vertical) or not, which is what causes the CRT shaders to appear vertical or not. the shader itself has no idea if it's running on a vertical game or not. it's just a program that does something to the pixels it's given.

    this is fine with (for example) lr-mame2003 as it correctly rotates games through the libretro API, so CRT shaders appear correct for vertical games.

    this is a problem with lr-imame4all, which rotates games internally, rather than using the proper API, so CRT shaders appear wrong for vertical games.

    so, what emulator are you using? ;)

    it's always worth filling out the entire support form for all issues. with respect, the people who know if they're relevant or not aren't usually the people asking for support ;)



  • @dankcushions

    Good point.

    If it is indeed an emulator based issue then he could simply just have explained it instead of posting the regular copy & paste stuff an admin or mod would usually post. And the "we all have a lives" comment was really not necessary. Not that I haven't spend any of my time to create a theme for this community, help people when I can and even donate to projects here.

    Or maybe I just woke up with a bad attitude today... not sure yet.

    So the emulator or core I am using is lr-fbalpha.


  • Global Moderator

    @flyingtomahawk said in crt-pi-vertical.glslp issue / horizontal lines only:

    @dankcushions

    Good point.

    If it is indeed a emulator based issue then he could simply just have asked for it instead of posting the regular copy & paste stuff an admin or mod would usually post. And the "we all have a live" comment was really not necessary.

    So the emulator or core I am using is lr-fbalpha.

    well, they didn't neccesarily know that it could be an emulator issue, so this is my point: rather than them, and now me, spend time asking for specific information, we have a template for support posts that asks for ALL information that will ever likely be needed, and then it's (hopefully) a matter of someone posting the solution.

    but hey, your post had way more information than most support calls i see at work so it's not so bad :)

    but never mind that now :) i will try 1942 in fba tomorrow and see if it produces vertical scanlines. i thought lr-fbalpha correctly rotated through the api so it should, but i can check.



  • @dankcushions said in crt-pi-vertical.glslp issue / horizontal lines only:

    i will try 1942 in fba tomorrow and see if it produces vertical scanlines. i thought lr-fbalpha correctly rotated through the api so it should, but i can check.

    Thank you.



  • @flyingtomahawk said in crt-pi-vertical.glslp issue / horizontal lines only:

    And after 50+ views I thought I ask if really no one could spare those 5 minutes to test and confirm.
    I am here every day and I see how many users are online and it seems to me that there are plenty of people that have a bit time to spare.

    I appreciate how frustrating that can be. The problem is that most people outside the development team, unless they use the specific module/emulator/shader that you are having issues with, are probably unlikely to want to do anything that may disturb their current setup. So of those users on here, only a limited number will probably ever try anything like that. I have a spare Pi3 and 2 sd cards which I write images from the site to for testing purposes, so I had a setup I could try it with.

    I apologise if you think I was being rude, but if you've spent any time here, you must see how many posts there are where the first reply is: "Can you complete the information?". The emulator is important, equally some of the most bizarre issues are caused by using an under-powered PSU.

    I must say that in my "live" system, I use overlays rather than shaders unless I want the barrel distortion effect as I've found that the overlays use far less CPU in general.

    As suggested by @dankcushions I've loaded 1942 Rev B into lr-fbalpha and the scanlines do rotate to vertical correctly, which games are you experiencing issues with?



  • @simonster

    I get the same result with every vertical shooter game that I have currently setup. I have 2 systems only at the moment, NeoGeo and Capcom Play System.
    Games like 1941, 1944, 19xx, Alpha Mission 2, Varth, Strikers 1945 Plus and a few others.
    I haven't changed anything, I just load the game and then access the Retroarch menu to load the shader.
    Is there anything specific that I have to do? Change resolution manually?



  • I tried changing the screen size in RetroArch and that didn't make a difference, so I think it can only be how the emulator is interpreting the rom. It isn't down to the viewport size being portrait or landscape (I can stretch 1942 to 16:9) and it still shows vertical lines. Can you try getting hold of a copy of 1942 (Rev B) for the correct romset on fbalpha and try that. It seems to work correctly for me using an Rpi3 and the current image.

    If this works, it is obviously down to the rom/emulator combination not flagging it correctly. I will note though that the vertical scanlines are very close together when rendered on a 16:9 monitor (to the point I was getting banding in the colours at 1920x1080 on 1942).



  • @simonster

    Will do that, thanks.
    I should have that rom somewhere.
    I'll test it today after I get back from work and report back.


  • Global Moderator

    i've tested it as well. works fine. are you 100% sure you're using 'lr-fbalpha' (there is another lr-fba emulator in retropie). i don't think using the right rom will make a difference (the wrong rom wouldn't load at all). you can't bypass the rotational code on a default retropie install. i'm not you can bypass it at all in lr-fbalpha without the game appearing the wrong way around.



  • @dankcushions

    Last time I checked, yes it is the lr-fbalpha emulator I am using (v0.2.97.39). But I'll check again and confirm that too.
    I only use lr-fbalpha2012 for one game, R-Type2, which wouldn't run with lr-fbalpha. And I don't use pifba which leaves only lr-fbalpha.

    I never tried 1942 (Rev B) before. I also could try Donpachi or Dodonpachi which "should" be 100% vertical.


  • Global Moderator

    @flyingtomahawk said in crt-pi-vertical.glslp issue / horizontal lines only:

    @dankcushions

    Last time I checked, yes it is the lr-fbalpha emulator I am using (v0.2.97.39). But I'll check again and confirm that too.
    I only use lr-fbalpha2012 for one game, R-Type2, which wouldn't run with lr-fbalpha.

    r-type2 has run for in lr-falpha for about a year. fbalpha is also on v.0.2.97.42 now. it sounds like you're running quite an old version, although it shouldn't make a difference for rotation.



  • @simonster said in crt-pi-vertical.glslp issue / horizontal lines only:

    I must say that in my "live" system, I use overlays rather than shaders unless I want the barrel distortion effect as I've found that the overlays use far less CPU in general.

    Me too at least for the vertical stuff I am using an overlay. I did compare overlay vs crt-pi for horizontal and the crt-pi shader looked a bit smoother but it does use more CPU power which can, sometimes, cause slow downs on games like Street Fighter III - 3rd strike or other SF games.
    I most likely will revert back to overlays for horizontal too for performance sake.

    Curious, what overlay(s) are you using?

    I use these here by ruckage.



  • @dankcushions @simonster

    I just tested it with the following roms

    Raiden
    Raiden II
    Raiden DX
    Donpachi
    DoDonpachi
    1942 (revision B)
    Gunbird
    Gunbird 2

    and all show vertical lines when I load the crt-pi-vertical shader.
    So I must have been unlucky because I tried roms like 1941, 1944 and 19xx and all of them don't load those vertical lines.
    It is good to know that the vertical shader actually works if you use the right emulator and rom.

    Thanks for the help. Something new learned again.



  • @flyingtomahawk said in crt-pi-vertical.glslp issue / horizontal lines only:

    Curious, what overlay(s) are you using?

    I have a set of arcade overlays that I got about 18 months ago. They all have machine bezels inside a fake cabinet with a background of an arcade along each side. I can't remember where they came from, but the screen in some of the images even has scratches and scuffs on it for authenticity.



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