Various

Prince of Persia related subjects that do not have their own boards.
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Norbert
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Re: Various

Post by Norbert »

Falcury wrote: February 5th, 2018, 5:25 pmSDLPoP has an optional fix for this, by the way.
Oh, "enable_remember_guard_hp".
Nice.
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Re: Various

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Norbert wrote: August 27th, 2017, 8:12 pm I wonder if it'd be possible to create a mod that's supposed to be played with your eyes closed. Probably with SDLPoP or MININIM, that the executable is modified to play specific sound effects that indicate the prince leaves a room or enters a different row. I'm not sure if this would work. Too much work to find out too, so I'm just writing about that this is something I was wondering. :)

[Edit: Hm. Or maybe only the prince could be visible and nothing else. Or perhaps just the prince and the potions? Or only the potions, and that one of the potions makes everything visible for half a minute or so?]
Somewhat related. Playing with an invisible prince, where only sound effects and room switching helps you.
PoP1 1.0 offset 0xC661, change it from 0x10 to 0x03.
(No idea about what that changes or why it works. Ran into this coincidentally.)
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Re: Various

Post by Falcury »

Maybe if we had directional sounds (footsteps and the like) that could also work well.
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Re: Various

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Norbert wrote: February 27th, 2018, 12:32 am Somewhat related. Playing with an invisible prince, where only sound effects and room switching helps you.
PoP1 1.0 offset 0xC661, change it from 0x10 to 0x03.
(No idea about what that changes or why it works. Ran into this coincidentally.)
It does something odd with guards: they are only pushed down a bit. The intro and the cutscenes also look odd.
So it's not perfect.

This is what your hack changes:

Code: Select all

seg008:1186 8B 5E 12                             mov     bx, [bp+chtab_id]
seg008:1189 D1 E3                                shl     bx, 1
seg008:118B 8B BF 38 43                          mov     di, chtab_addrs[bx]
seg008:118F 8B 5E 10                             mov     bx, [bp+id] ; <-- here
seg008:1192 D1 E3                                shl     bx, 1
seg008:1194 D1 E3                                shl     bx, 1
seg008:1196 C4 59 02                             les     bx, [bx+di+(chtab_type.images-4)]
seg008:1199 8B 46 0A                             mov     ax, [bp+ybottom]
seg008:119C 26 2B 07                             sub     ax, es:[bx+image_type.height]
seg008:119F 40                                   inc     ax
seg008:11A0 89 84 3A 3D                          mov     midtable[si]+midtable_type.y, ax
That's in add_midtable().
Specifically, it's the part that finds the image for the purpose of subtracting its height from the y coordinate.
(Note: In SDLPoP I factored out a part of this to get_image().)

Code: Select all

	image_type* image = get_image(chtab_id, id - 1);
	if (image == NULL) {
		return 0;
	}
	midtable_item->y = ybottom - image->h/*height*/ + 1;
The hack changes the local variable reference from [bp+id] ([bp+0x10]) to [bp+3].
[bp+3] is the middle the return address or something, so the hacked prince.exe ends up selecting the height a random out-of-range image, but from the correct chtab.
That's why the guards end up only somewhat below their intended position: The blindly selected y-offset from the guard chtab does not push them offscreen, as opposed to the kid chtab.
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Re: Various

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Someone added two mods (Princess of Persia and The Great Escape) to Google Play.
To make money off of them, it looks like (ads and in-app purchases).
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Re: Various

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Norbert wrote: May 19th, 2018, 4:34 pm Someone added two mods (Princess of Persia and The Great Escape) to Google Play.
Their other apps also look like emulated DOS games, like Zool or Dangerous Dave.
Norbert wrote: May 19th, 2018, 4:34 pm To make money off of them, it looks like (ads and in-app purchases).
I wonder what in-app purchases do, since the original games are not prepared for them.
Maybe the player has to pay after some amount of time to continue playing?
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Re: Various

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GitHub lists Mechner's PoP source code among the most notable things that happened on GitHub in the past ten years:
https://github.com/ten#2015 wrote: Apart from active game development, public source code for some of the most influential games of all time, including Doom and Prince of Persia are archived in public repositories—certainly a better fate than being buried in the New Mexican desert.
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Re: Various

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29 Years ago, on 3 October (yesterday), PoP for Apple II was released.
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Re: Various

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Recent thread on ResetEra about PoP modding:
https://www.resetera.com/threads/the-or ... ity.89895/
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Re: Various

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Has anyone ever finished the DOS or SNES port without pressing Shift anywhere?
Are both finishable without using Shift...
Related: https://www.youtube.com/watch?v=wkC91Y3uobY

What about not using the down arrow...

Or both, not using the down arrow and not using Shift? :lol:
[Edit: Hm... I don't think 'both' is possible. I cannot pass the second guard in level 2, because I cannot sheathe (put away) the sword.]
[Edit 2: Haha, I passed him with trick 35.]
[Edit 3: Finished levels 1 and 2 without using the down arrow or Shift.]
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Re: Various

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Norbert wrote: March 8th, 2019, 12:09 amOr both, not using the down arrow and not using Shift? :lol:
[Edit: Hm... I don't think 'both' is possible. I cannot pass the second guard in level 2, because I cannot sheathe (put away) the sword.]
[Edit 2: Haha, I passed him with trick 35.]
[Edit 3: Finished levels 1 and 2 without using the down arrow or Shift.]
Well, it was fun while it lasted. :P
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Re: Various

Post by David »

Norbert wrote: March 8th, 2019, 12:09 am Has anyone ever finished the DOS or SNES port without pressing Shift anywhere?
Are both finishable without using Shift...
Well, last time I checked, there was no Shift on the SNES controller. :)
Of course I know you mean the SNES version's equivalent of Shift. (the A button)
Norbert wrote: March 8th, 2019, 12:09 am Related: https://www.youtube.com/watch?v=wkC91Y3uobY
"Prince of Persia 1 Level 10 without SHIFT".
However, the prince starts with 8 HPs, so the player obviously used Shift on previous levels, to drink the big potions. :)

At the second purple guard, I usually turn him left, and sneak right under the gate, so I can surprise the guard from behind.
It's much easier than to go through those chompers.

The hardest part on this level (when playing without Shift) is dealing with the yellow guard.
Norbert wrote: March 8th, 2019, 12:28 am Well, it was fun while it lasted. :P
Yeah, you can't make that jump without Shift.

You'd also need a run-jump with grabbing on further levels:
* Level 8: In the rightmost room.
* Level 11: (1) In the second room, (2) before the exit.
* Level 12: (1) Right after you ran past the spikes, (2) right after the gate.
Although you can skip the second if you do a two-tile run-jump from above the gate.
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Re: Various

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David wrote: March 9th, 2019, 9:24 pmYou'd also need a run-jump with grabbing on further levels:
* Level 8: In the rightmost room.
* Level 11: (1) In the second room, (2) before the exit.
* Level 12: (1) Right after you ran past the spikes, (2) right after the gate.
Although you can skip the second if you do a two-tile run-jump from above the gate.
If down arrow is allowed, your level 11(2) is possible with hopping.
Your level 12(1) is possible by simply going up after the spikes, unless I'm overlooking something.
There are some other challenges and impossibilities throughout the levels.
The Jaffar fight, for instance, and if down arrow is disallowed the shadow and skeleton fights.
Not all guards may be passable with tricks.
Maybe other unforeseen problems?
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Re: Various

Post by David »

Norbert wrote: March 10th, 2019, 12:15 am If down arrow is allowed, your level 11(2) is possible with hopping.
You're right.
I always played that part with holding shift (and without hopping), but then the prince loses one HP.
With your method he doesn't lose any HP.
Norbert wrote: March 10th, 2019, 12:15 am Your level 12(1) is possible by simply going up after the spikes, unless I'm overlooking something.
You're right again, I overlooked that shortcut.
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Re: Various

Post by Norbert »

A November 2005 article "The Art of Jumping" by Joris Dormans uses PoP as one of the examples.
(First, it's briefly mentioned. Later, its secrets, tests, triggers, riddles and such are being discussed.)

https://web.archive.org/web/20171111004 ... tofjumping
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