windowposition doesn't seem to work with openglnb, wondering how to offset windowresolution from fullresolution

[miranda]

I thought I should try a discussion instead of opening a bug, because I don't really understand what is going on with this...

I'm running what is probably a rare setup for DOSBox-X, I'm using a 15KHz CRT using switchres and a superresolution of 2560x240. This is a common way to run the emulator Retroarch, as it is even built-in to Retroarch... but I just run it on my desktop all the time for a second display.

Fortunately I was able to get DOSBox-X set up to work with this... but it was a pain in the ass and very hacky. In order to get it to display properly, I have to use a lot of KDE window rules and a launcher script for DOSBox-X.

my script looks like this:

#!/bin/bash

xrandr --output DisplayPort-1 --mode 2560x240 --scale 1.0x1.0
feh -F -Z --no-menus -. ~/.local/share/feh/crt_backdrop_black.png &
FEH_PID=$!

cd ~/DOSBox-X
/usr/bin/dosbox-x "$@"

kill $FEH_PID
xrandr --output DisplayPort-1 --mode 2560x240 --scale 0.25x1.0 --filter nearest

The xrandr parts are just to switch to full 2560x240 mode. When not running a game on the CRT I scale the horizontal resolution to what is effectively 640 so I can use the desktop for terminals and other things without it being squished to something unreadable. But when running an emulator you don't want that because you just lose resolution.

Anyway, for my DOSBox-X config I have these relevant settings:

fullresolution    = 2560x240
windowresolution  = 2240x200
windowposition    = -

aspect         = false
doublescan     = false
scaler         = none
glshader       = pixel_perfect.glsl

it's running in openglnb output mode, which is required by the shader. The shader makes it so in DOS I can change between 640x200 and 320x200 modes and it will scale the screen without messing up pixels to 2240x200. This all works great. The problem is, the windowposition setting doesn't really work. "-" is the only thing that doesn't have unintended side effects. I'm not sure how this parameter is really supposed to work, but I expected it to provide an offset on the screen. The first thing I tried was 160, 20 which I expected to create an overscan border between windowresolution and fullresolution. It does not.

I found no way to position the 2240x200 viewport in the center of my screen using any options in DOSBox-X.conf. It would ether jam the 200 lines picture up at the top into the overscan, or it would stretch the whole thing to 240 lines. So the solution I found was use KDE window rules to force the position of the window (fullscreen mode doesn't work) to the center of the screen and remove the window decorations. This left an overscan border around the DOSBox output where I could see my wallpaper. I solved this by running feh with a solid black image for a backdrop, and used another KDE window rule to force it to be under all other windows.

The end result is basically perfect, and I've never seen DOS games look so good.. But it's disappointing this is so complicated. I'm not even sure if it would be possible to do this at all with any DE other than KDE.

So I guess I was just wondering, is this a bug that the windowposition option doesn't work as I expected? Or should it be a feature request to be able to position the windowresolution offset inside the fullresolution? I know there is an overscan setting but I don't know if it does what I would expect... and it only goes up to 10. Proper overscan for a 200 line DOS mode would need to be at least 20 or 40, depending if you are talking about total difference or one side of the border (240 - 200).

Anyway that's the situation. Like I said, I admit this is probably a rare use case of DOSBox-X, but it's not for other emulators like RetroArch.

[miranda]

No responses... That makes me sad.

No love for 15KHz CRTs here?