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rdoeffinger / xwa_ddraw_d3d11

Direct3D 11 implementation of DDraw.dll for XWA
MIT License
63 stars 2 forks source link

Flickering issue #10

Closed bguthrie1 closed 5 years ago

bguthrie1 commented 5 years ago

There seems to be some sort of flickering issue with the latest development.

Here is a link to the video showing the issue: https://1drv.ms/v/s!AoEpIrw6LOkUjccrXpg7AEqFc9lAlQ

rdoeffinger commented 5 years ago

Any idea since when? This kind of looks like standard Z fighting, which should not be affected by the kind of changes me or Jeremya have been doing.

bguthrie1 commented 5 years ago

It seems this doesn't happen with 1.5.7 for some reason.

rdoeffinger commented 5 years ago

@JeremyAnsel this issue seems to go away for me if I revert the 16 bpp texture support. Can you confirm? (to reproduce you can start a Skirmish in an A-Wing against a couple of buoys, numpad * to switch to external view, numpad / to be able to rotate the view - flickering engine lights I guess are intentional, but the border between the red and white part of the rear A-Wing part for some reason starts to flicker)

commit 0082089579764afc78aebc3330b365cfcc04b2e5 Author: Jérémy Ansel JeremyAnsel@users.noreply.github.com Date: Tue Jan 15 14:08:56 2019 +0100

Add support for 16-bpp in texture loading
rdoeffinger commented 5 years ago

ddraw.zip Binary with the change to disable upload of 16-bit textures, which seems to fix the issue for me.

rdoeffinger commented 5 years ago

Note: We are both running NVidia graphics. Since I think there might be a risk of this being some hardware/driver issue? Not overly likely I admit, but I don't have a good explanation for the issue otherwise. Edit: I can confirm no flickering on laptop with Intel graphics. It's no guarantee, but it means it's at least possible it's an NVidia issue.

bguthrie1 commented 5 years ago

The above ddraw fixed the issue on my end.

JeremyAnsel commented 5 years ago

Strange, I haven't flickering issue with version 1.3.6 with either Intel or NVidia graphic card. I've tested in skirmish with an A-Wing. The flickering engine glow is intentional.

rdoeffinger commented 5 years ago

You are right Jeremy, sorry. The problem seems to be connected with my implementation of ATEST (necessary for the old games, but XWA does not seem to care much if you just ignore it). Using 16-bit textures seems to change the alpha interpolation and then causes part of the A-Wing to go missing.

rdoeffinger commented 5 years ago

I don't understand it, sometimes the alpha value for 565 textures is 0, and it's not the border colour. Either something is going on I don't understand or alpha for 565 textures is buggy on NVidia cards.

rdoeffinger commented 5 years ago

xwing_ddraw_d3d11_1.5.8_rc1.zip Ok, if there are no more issues anyone spots, I think I'll make a release of that one...

bguthrie1 commented 5 years ago

Haven't seen the flickering issue so far. I think its ok to close this one.

rdoeffinger commented 5 years ago

Ok, thanks, closing.