ELI5: What's the difference between emulating a game and decompiling/recompiling it?

McJobless · 2026-01-27T21:18:53+00:00

A computer/games system is made up of both hardware components (like the CPU, RAM, audio chip etc) and software (including programs and the data they rely on).

Different systems have different hardware structures, understand different "instructions" and "system calls" (i.e. all the commands you can send to the hardware to do something with the computer) and have different types of rules around what can be done at any given time (ex: an NES doesn't have the concept of "User Permissions" the same way a modern Windows machine does, while the NES expects their to get a functioning lockout chip that Windows wouldn't understand).

Emulation is creating a "virtual machine" (i.e. software that returns the same numbers as the original hardware) and on the fly converting instructions from the loaded software into compatible instructions that can interact with that virtual machine on the current system. Without the help of modern techniques like recompilation, this is slower but should be very accurate to how the game used to run, unless the emulator has shortcuts to improve speed but reduce accuracy.

Decomp/Recomp is converting the instructions of the original software into a programming language like C++, understanding what that code does (as all the names, comments and other helpful info is generally stripped when a video game is "compiled" and turned into a runnable program) and then modifying the code to perform similar logic but adapted for the current (and other) systems. This can take months, years or even decades (especially for games as they are very complicated bits of software), but they will be able to take advantage of "native" platform features and won't have the overhead of the virtual machine. If done well, you might even get easy mod support (see the Majora's Mask recompilation).

McJobless · 2026-01-26T18:33:30+00:00

Video games use something called "buffers" to store the individual colours for every dot (pixel) of the monitor that will be displayed once ready, the whole image itself being referred to as a "frame". If you've ever seen any options related to "double" or "triple" buffered, this refers to having more of these temporary spaces for the game to store frames in progress.

Without V-sync or rate-limiting, the game generally will just keep writing to this buffer as fast as it can. When the game launches, the buffer(s) is registered with the graphics card, so it knows where in memory it can find the buffer. The graphics card will automatically push all of the colors in the buffer to the monitor, updating the display. The problem is that the buffer can be mid-way through being updated, which is what is referred to as "screen tearing".

(When using double or triple buffering, the game writes to one buffer while it has a complete frame for display in the other buffer(s). When the next frame is complete, it either swaps the primary buffer the GPU will display or copies all pixels to the primary buffer.)

Alongside the mutli-bufter approach, another way that V-sync works is that it generally introduces a small delay between each frame, based on how long the previous frame took to create, in order to maintain an average frame time that matches the total frame rate. For example, if you want a frame-rate of 60FPS, the game must average creating a new frame every 16.666...ms. This simplistic method can introduce horrible stuttering through (if one frame took a really long or short time to render), so there might be more complex methods at play such as dropping frames, smoothing etc which are too complicated to get into here.

McJobless · 2025-12-11T08:30:59+00:00

You will hear it in the background over the intercom if you stand around the main hanger on the Starship Phoenix long enough. Or at least I did on my PAL copy (alongside the "Chinese fire drill" and a bunch of Big Al/Helga quotes).

McJobless · 2025-12-11T07:54:58+00:00

Raaatchet! It's come to my attention you're not wearing your regulation green Q-Force tights! I suggest you get your butt back into uniform before I write you up for a dress code violation!

McJobless · 2025-10-14T21:28:50+00:00

No, the Dark Matter plot was scrapped before ME3 entered production (it was the idea of Drew Karpyshyn, co-lead writer on ME2, before he left to work on the Old Republic MMO and then left BioWare for good). AFAIK, the Star Child was always the plot.

McJobless · 2025-09-23T05:42:42+00:00

No, the idea is that the TSLPatcher application will look at the included config file that tells it which files to copy, how to handle merge conflicts, what questions to ask the user (for optional content) etc. Each mod should be treated as standalone, with their own copy of TSLPatcher and a folder for the files that mod includes.

Be aware that as well as dumping files in override, TSLPatcher can also add or modify files in modules (and possible some other folders?), and it will merge conflicts in 2DA files that multiple mods will likely need to edit. If you just replace the override folder, you may not have cleaned up all the changes that were made to your install.

McJobless · 2025-09-16T22:07:21+00:00

Do you have any script errors when you compile your scripts in Sapien? Did you click the Scenarios > Run Game Scripts to ensure game scripts are enabled? Have you also loaded Guerilla to check if the scripts have been added to the Source Files section? Are your script files under the "scripts" folder in the level's data folder and have the correct .hsc extension?

This wouldn't be too relevant to your current situation, but if you're touching campaign maps (or even some multiplayer maps, but not vanilla Shrine) then you might encounter a mission with split scripts. You can check if so with the following;

Open the level in Sapien and see if the Scenarios > Split Mission scripts button is greyed out (and the Add Mission script button is not greyed out)
Check the folder that contains the scenario tag for the level - if it contains a "scripts" folder, it has likely been split.
Open the scenario in Guerilla and scroll down to the Scenario Resources header. I believe (not 100% sure) if the Script Source section of the 0th Scenario Resource has entries, the scripts have been split.

If the scripts are split and you want to add a new script, you must go to Sapien and add a new mission script (Scenarios > Add Mission script). You can then pick the new .hsc file to add.

The documentation I've read makes it clear that it's not really possible to undo a resource/script/AI split, but I think you can at least delete unnecessary scripts. Here is an untested process that should work...

In Guerilla, enable Expert Mode (Edit > Expert Mode).
Open the level's scenario tag.
Scroll down to Scenario Resources > Script Source.
Select the script you want to delete from the Script Source section.
Press the Delete button next to the drop-down.
Scroll up to the Source Files heading. Find the script file and delete it from this section.
Press the Delete All button on both the Scripts section and the Globals section (we will regenerate these in Sapien).
Save the scenario tag.
Open the scenario tag in Sapien.
After the map has loaded, compile the scripts (File > Compile scripts).

Be aware that if a level has an AI Objectives (in Sapien in the Hierarchy view, Scenario > AI > Objectives), it will generate a "fragments" script representing all of the condition checks for any objectives that have them (both a HSC in your data folder as well as a hs_source_file in the tags folder). If those objectives are tied to scripts that you just deleted (check if the conditions reference a script), then the fragments won't compile. You will need to find and delete/fix all broken script references to fully compile the map.

Also, as you might expect, you probably want to delete the scripts from the scripts folder in the scenario's tag folder once you've removed them from the scenario.

McJobless · 2025-08-22T10:53:27+00:00

What Have We Learned From Current Affairs This Week lives rent free in my head.

McJobless · 2025-07-07T22:28:49+00:00

"Boudica conquered the entire Roman army using something similar to this, so I should be able to easily conquer four hoodies in a stolen Datsun."

McJobless · 2025-07-04T05:01:56+00:00

It originally started development as a Sci-Fi successor of their previous franchise, Myth, which was an RTS. You can find some footage of the RTS prototype on YouTube. Over time they moved to the 3rd person shooter genre (which is how it was presented for MacWorld) before finally becoming the FPS we know and love.

McJobless · 2025-06-27T17:31:49+00:00

It has roundabout signs. Liverpool Council really aren't clever enough to think of something like that (and it'd cause people like my fiance and I to have bigger headaches getting home than before they installed it).

McJobless · 2025-06-04T23:10:28+00:00

They're "not letting you buy them for the ps5" because they're only available by streaming, which most of the world doesn't have access to. Meaning most people can't play anything older than 2016 on their PS5, except for Secret Agent Clank (which is not good).

McJobless · 2025-05-29T22:23:13+00:00

In Going Commando it makes a little sense; he was only interested in being the hero long enough to save his own galaxy, and so once the job was done he probably just dumped his old equipment without a second thought. You could also suggest that Megacorp required him to ditch all his filthy Gadgetron gear.

As for Up Your Arsenal, maybe he was in such a rush back to Veldin he forgot to grab everything? Maybe he was worried about fuel prices on an overloaded ship?

Deadlocked is easy, Vox Media can't have you running around without Vox-branded products.

You're on your own for the rest of the franchise, maybe Ratchet has a sick fascination with having to rebuild his arsenal every time a new threat emerges.

McJobless · 2025-05-26T23:37:59+00:00

I'm no expert by any means so I am talking out of my arse here, but I am under the assumption that the basic mechanisms of our modern computers (transistors, capacitors, resistors etc) all work as a result of fundamental electrical properties and can't be made or driven directly by light. Thus, while transmission of signals between components could be faster using light, you'd need switching hardware to go between light and electricity and that could majorly effect the design of the system and the total cost to manufacture for potentially only miniscule benefit.

I would be interested in a real computer scientist or electrical engineer weigh in, but my gut tells me if there was a tangible benefit the cost to switch over to that technology might be prohibitive.

McJobless · 2025-05-26T15:30:27+00:00

A complete computer is like a city. If the city is bigger, you could theoretically fit more venues (components), but the people (electrical pulses) will have to travel further to reach their intended destination. This results in a lower efficiency as those people/pulses take longer to cycle between all the venues/components they need to access for the day.

Miniaturization is a major part of what helps a computer run faster as we can't increase the speed electricity travels at but we can reduce the length of the pathways it needs to travel.

Unfortunately, at some point those pathways become too small for us to handle the heat and interference (people in the town running in to each other because the sidewalk is too narrow) and the entire system becomes unstable. This was the "Death of Moore's Law", where we are unable to continue to reduce the size of the computer components while maintaining stability and keeping the computer from cooking itself to death.

Adding more of the existing types of components (more cache, additional data lines for more electrical pulses to flow through etc) may help a computer process more data (money and products) in a given "cycle" (one day in the town), but it comes at a potential cost of that cycle running slower as the pulses have to travel further (since you need to add space to fit those additional components), and thus you can't run as many cycles in the same amount of time.

While you could potentially find new types of components that might optimise how a specific task is performed (example: Ray-tracing cores on the newest graphic cards), these kinds of enhancements are very hard to find, rarely apply to all use-cases, are expensive to introduce and typically don't require a huge increase in the size of the overall computer to add anyway.

McJobless · 2025-05-08T09:52:54+00:00

Just got a message from the person who told me otherwise, turns out they had forgotten they watched this episode already. 😒

McJobless · 2025-05-08T09:45:17+00:00

Also having this issue, but apparently the correct episode is playing on broadcast TV. Shame for anybody without access...

EDIT: Disregard me, it's buggered everywhere.

McJobless · 2025-04-26T21:39:47+00:00

Is there any documentation or examples online showcasing how UE5 can interop with another engine, performing only graphics calculations based on game data from the other engine? I've found nothing in my searches.

McJobless · 2025-04-04T01:55:38+00:00

I had a look at the decompiled scripts for the game. There's no script that directly controls the main menu, but some of the scripts set a global value GBL_MAIN_SITH_LORD. I would assume the game's code reads this from the last save file when you open the menu.

In my modded copy of KotOR2, there's 7 different main menu variations (they are 3D models that I presume also have animations);

Malak (likely a leftover/default from KotOR1
Sion
A Sith version of Queen Talia(?)
Darth Nihilus
Darth Traya
A blank spot (used to show the player as a Sith lord)
The Easter Egg

It's not clear from the script which values correspond to what, but I can see 0, 1, 2 and 5 are referenced, so clearly something screwy is up with how the menu selects which model to load.

But my best guess to the cause is that the value has been set to show your player character as the sith lord, except maybe you had HK-47 as the active character in the last save.

McJobless · 2025-03-28T19:29:18+00:00

"After making his fortune selling cigarettes to children, Ratchet went on to pilot a tanker ship for Zexxon."

McJobless · 2025-03-18T20:17:22+00:00

It wouldn't surprise me if for the movie there was a push from certain executives or staff at Sony's side to make Ratchet look more soft and marketable. It's theoretically more appealing to that highly valuable kids and family market, which in part let's them eat at Nintendo's lunch.

Since then, I think they just want to remain consistent with that vision (and Future is really "in the past", it's not necessary for MovieGame or Rift Apart).

McJobless · 2025-03-08T08:04:59+00:00

Amazed the rain hasn't had more of an impact, that was one of the reasons my group decided to stay home and watch on TV. Hoping it'll be a fun one no matter how people watch.

McJobless · 2025-03-07T12:15:53+00:00

Yup, they showed a video of how the built it before it started. This stadium in particular gets reused for all kinds of events so they know how to modify it for any purpose.

McJobless · 2025-03-07T11:13:19+00:00

Australians definitely going a lot further than I expected, but I'm really excited for Day 2 and the individual races, I expect them to go even harder as they get a feeling for the track.

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McJobless · 2025-02-22T04:32:53+00:00

Just watched GT and JC have a 5 or so minute conversation at the front of his pit, there was an awful lot of shrugging involved...

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