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fbergama / pigfx

PiGFX is a bare metal kernel for the Raspberry Pi that implements a basic ANSI terminal emulator with the additional support of some primitive graphics functions.
MIT License
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mode4h / 320 x 200 -- apears off screen #46

Open lindoran opened 4 years ago

lindoran commented 4 years ago

was testing the CGA 4 color resolution with a custom pallet I don't know if this is a limit of the PI, the monitor or the software ; but when I do 320 x 200 some of the pixels draw off the screen; this issue is not present in 640x480 or 320x240. this issue happens even with the Xterm pallet. this is with composite output.

lindoran commented 4 years ago

see how the image is off center: PXL_20201003_231116674

320x240 it's centered in a 4/3 aspect on the screen: PXL_20201001_044039696

lindoran commented 4 years ago

Looks like the same issue with 640x350 (only more of it renders off screen and is far shorter top to bottom). The upside is 640x480 / 320x240 are likely to be the most used resolutions due to this being evenly scalable to other common resolutions.

chregu82 commented 4 years ago

Actually I don't think there's much I could do about this. I tried different resolutions on a Pi 4 with a VGA monitor connected to the HDMI port. What this does if I change to a resolution which is not 4:3 is, it adds top and bottom black bars to get it to 4:3 again. This is all Pi firmware related. I only can choose a resolution for the framebuffer. I don't have a composite monitor to test with. It's probably even different with a 16:9 or 16:10 monitor connected with HDMI.

lindoran commented 4 years ago

I figured something like that was the case. Those other resolutions are less useful so I don't think it's a huge deal, but if it's a known issue my only thought would be to update the document or disable those resolutions as they don't perform as expected on other monitors. Thanks for the answer 🙂

On Sun, Oct 4, 2020, 2:05 AM Christian Lehner notifications@github.com wrote:

Actually I don't think there's much I could do about this. I tried different resolutions on a Pi 4 with a VGA monitor connected to the HDMI port. What this does if I change to a resolution which is not 4:3 is, it adds top and bottom black bars to get it to 4:3 again. This is all Pi firmware related. I only can choose a resolution for the framebuffer. I don't have a composite monitor to test with. It's probably even different with a 16:9 or 16:10 monitor connected with HDMI.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/fbergama/pigfx/issues/46#issuecomment-703213205, or unsubscribe https://github.com/notifications/unsubscribe-auth/AQIK5ZFIEZJT5TBODBIBK4TSJANDFANCNFSM4SDJ2FQQ .

willtco commented 3 years ago

That is most probably your monitor (it certainly looks a few years old), it should have size and position controls which you can use to correct it.