[Fixed] Boom compatibility - Passthru

[larsboy]

I've noticed some problems with Boom compatibility. One thing that seems to cause quite a few problems, is the Passthru flag of linedefs not working. With Passthru, several buttons can be placed right behind each other, and using the first one uses them all at once. In ZDoom, you must keep pushing, using one linedef each time, so you must push the button many times.

This is used f.ex. in Phobos Anomaly Reborn, making that excellent episode not work in ZDoom (other than this, it seems to work fine). In E1M3, there are two buttons you must press many times to get all the effects. Also, on the large crane on that level, the button on the elevator is supposed to raise an invisible floor to enable a 3D effect in addition to raising the elevator, and there is no way to get both to happen, breaking the level in ZDoom (the readme of PAR says there are no fatal flaws with ZDoom, so perhaps this was broken recently).

[HotWax]

Make sure you're using 2.0.56, and try again.

[larsboy]

I used 2.0.55 (and 2.0.47i), has it been fixed since? Downloading 56 now.

[Graf Zahl]

Actually, I noticed that problem, too, while playing P:AR (with 2.0.55). The 2 generators in the southeast area of E1M3 had to be activated multiple times until they did what they were supposed to do. AFAIK 2.0.56 hasn't changed anything about the switch code.

[Graf Zahl]

Ok, here's what happens:

At the beginning of P_TranslateLinedefs we find the following line of code:

Code: Select all

	flags = flags & 0x01ff;	// Ignore flags unknown to DOOM

Later we have this:

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	passthrough = (flags & ML_PASSUSE_BOOM);

And guess what? ML_PASSUSE_BOOM is 0x200 so it is cleared by the first of the two lines before the code has any chance to examine it! In v1.22 the order of these 2 lines was inversed so why could this ever happen?

[randi]

Fixed.

[larsboy]

Since rh-log.txt in the source for 57 says that it's fixed, I assume it was supposed to be fixed in this version. Well, passthru don't work in 57

[Ty Halderman]

Since rh-log.txt in the source for 57 says that it's fixed, I assume it was supposed to be fixed in this version. Well, passthru don't work in 57

Well, the code that Graf Zahl quoted has been changed for .57. Randy now has those lines together at the top of the function as:

Code: Select all

	passthrough = (flags & ML_PASSUSE_BOOM);
	flags = flags & 0x01ff;	// Ignore flags unknown to DOOM

so the variable passthrough is now set before the bit is cleared. Whether or not the rest of the logic works is a different issue, of course. In fact I'd be inclined to think that passthrough-specific logic could rather easily not have been tested much, since it never was allowed to execute in the first place .

[PSchmitz]

Another problem (or feature - not sure which) with the pass-thru flag:

if you set the player use pass-through flag on a line that holds a valid switch texture, the switch effect for that texture does not work (texture doesn't change/no sound produced).

So. Is it a bug or an expected feature?

Paul Schmitz (another old DOOM guy)

Edit: fogot to mention - I am using cab57 (see previous line).

[Graf Zahl]

Definitely a bug. The code that switches the texture only checks for types USE and IMPACT on the line but not for USETHROUGH (which unlike Boom is a separate activation type in ZDoom)

[randi]

Well, passthru don't work in 57

I tested it with boomedit.wad, and it worked fine.

[Graf Zahl]

In P:AR E1M3 it didn't work. I was able to activate only one switch at a time.

[randi]

Fixed again. It was only working for lines that used Boom's generalized line types and not for lines that used normal line types.