[v1.1] Flipper - DoomGuy's World Gone Backwards

[Rachael]

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Warning: This mod requires OpenGL 3.3 or greater, and it is recommended you run it on a modern version of GZDoom!
Note: This mod requires GZDoom 4.3.x or higher or compatible!

Github

Ever wondered what it would be like to live in a mirror universe?

Well, now you can find out!

This mod reverses the entire world on its Y axis, making everything a mirror of itself.

It should be compatible with nearly any game, mapset, or other gameplay mod.

CREDITS: Gutawer and Nash Muhandes helped a little bit with this, and ideas and small code snippets were also used from Tilt++.
v1.1 Release

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flipper_alpha_v0.2.pk3

flipper_alpha.pk3

v0.4 Alpha

[BerserkerNoir]

NICE!
Something so basic like this can change the pace of the gameplay, reminds me when I was younger and played TLOZ Master Quest or Twilight Princess in Wii version.

[Rachael]

Thank you, and yeah, that's part of why I put it here. It will confuse you about which is left and which is right, which, until you get used to the levels in their "new" format, you're going to be stuck exploring once familiar levels all over again!

It's also good for testing your own levels from a "new perspective". Might help you spot misalignments and bugs that you've gone blind to!

[Toberone]

This makes me want a mod where you go backwards thru levels like its mario kart lol. Cool Stuff tho, strange how much a simple change like this makes everything so unfamiliar.

also for some reason my weapons not being flipped is making my brain go haywire, I keep thinking everything is still on the other side for certain secrets and areas

[NightFright]

There is a similar mod out there for EDuke32. I was wondering when it would finally be available in GZDoom as well. Thanks a lot for making it happen!

[Beed28]

The game seems to crash when moving to a new level; I was running Russian Overkill if anyone's curious.

Code: Select all • Expand view

MAP02 - Underhalls

VM execution aborted: tried to read from address zero.
Called from FlipperInventory.Tick at flipper_alpha_v0.2.pk3:zs/flipper.zsc, line 89

[Rachael]

Thanks. Pushed a fix and published a new version.

[Rachael]

Minor update: Mouse movement should be a little bit smoother now. The angle tracking was stored in a float instead of a double, and it seems like GZDoom still sends the player angle as fixed point, which doesn't fit in a float, but fits perfectly fine in a double.

[Nems]

Oooo, gonna have to give this a spin once I clear out my mod backlog. <3

[doomfiend]

I think there might be an issue with sound? enemies in the flipped version will have sound generate on the opposite speaker? i.e imp charging me on the right side of the screen and his alert / attacking sounds will come out on the left ear or is that just a me issue?

[Rachael]

That is an issue that can't be solved easily without redoing the mod a different way. The current implementation simply uses a shader to flip the view and some ZScript hackery to reverse your angle. Unfortunately, there's no way to reverse the sound.

[Nash]

I think there might be an issue with sound? enemies in the flipped version will have sound generate on the opposite speaker? i.e imp charging me on the right side of the screen and his alert / attacking sounds will come out on the left ear or is that just a me issue?

It's not just sound, even the automap doesn't match the 3D view. As Rachael explained, this is a simple shader effect that only works on the 3D view that merely mirrors it.

Rachael if you could pull it off with the LevelCompatibility idea I was talking about in PM, I look forward to doing a serious playthrough with it. XD It's gonna mess my brain up so bad!

[Rachael]

Doing the LevelCompatibility method will take a lot of work and will have a few caveats - notably that some scripted interactions are likely to break. Anything using absolute coordinates for the map or textures (since those will be reversed) will probably break as well. Any level that does not use scripts (i.e. vanilla Doom/Heretic maps) will probably function just fine. Maps that use MapSpots instead of absolute coordinates will function fine, as well.

However, if possible, the linedefs will be properly flipped to the new orientation, so front/back linedefs will continue to function.

The idea is thus: First all verteces are flipped on their X axis over (0,y) (simply by multiplying by -1). Then, each line will have its vertex references reversed. This will flip vertical lines properly, and will also properly maintain the orientation of horizontal lines. Afterward, the length of each line will be measured, the texture scale will be multiplied by vec2(-1, 1), and the offset will be added by the length of the line. This should help to maintain texture alignments throughout the entire level.

[AlphaSoraKun]

This is probably gonna be a mistake I make, but judging by screenshots, this is Funny AF!

[Rachael]

This is probably gonna be a mistake I make, but judging by screenshots, this is Funny AF!

It's meant to be. Part of the joke is how you go into familiar areas and get completely lost because you lose your sense of left and right.

When I get the LevelCompatibility version done, I'll post a gameplay vid of E1M1 or MAP01.