3927bb9713
This patch restores some 2.2 behavior, fixing a regression caused by the refactor of properly using std::vectors. In 2.2, the game allocated 200 items in obj.entities, but used a system where each entity had an `active` attribute to signify if the entity actually existed or not. When dealing with entities, you would have to check this `active` flag, or else you'd be dealing with an entity that didn't actually exist. (By the way, what I'm saying applies to blocks and obj.blocks as well, except for some small differing details like the game allocating 500 block slots versus obj.entities's 200.) As a consequence, the game had to use a separate tracking variable, obj.nentity, because obj.entities.size() would just report 200, instead of the actual amount of entities. Needless to say, having to check for `active` and use `obj.nentity` is a bit error-prone, and it's messier than simply using the std::vector the way it was intended. Also, this resulted in a hard limit of 200 entities, which custom level makers ran into surprisingly quite often. 2.3 comes along, and removes the whole system. Now, std::vectors are properly being used, and obj.entities.size() reports the actual number of entities in the vector; you no longer have to check for `active` when dealing with entities of any sort. But there was one previous behavior of 2.2 that this system kind of forgets about - namely, the ability to have holes in between entities. You see, when an entity got disabled in 2.2 (which just meant turning its `active` off), the indices of all other entities stayed the same; the indice of the entity that got disabled stays there as a hole in the array. But when an entity gets removed in 2.3 (previous to this patch), the indices of every entity afterwards in the array get shifted down by one. std::vector isn't really meant to be able to contain holes. Do the indices of entities and blocks matter? Yes; they determine the order in which entities and blocks get evaluated (the highest indice gets evaluated first), and I had to fix some block evaluation order stuff in previous PRs. And in the case of entities, they matter hugely when using the recently-discovered Arbitrary Entity Manipulation glitch (where crewmate script commands are used on arbitrary entities by setting the `i` attribute of `scriptclass` and passing invalid crewmate identifiers to the commands). If you use Arbitrary Entity Manipulation after destroying some entities, there is a chance that your script won't work between 2.2 and 2.3. The indices also still determine the rendering order of entities (highest indice gets drawn first, which means lowest indice gets drawn in front of other entities). As an example: let's say we have the player at 0, a gravity line at 1, and a checkpoint at 2; then we destroy the gravity line and create a crewmate (let's do Violet). If we're able to have holes, then after removing the gravity line, none of the other indices shift. Then Violet will be created at indice 1, and will be drawn in front of the checkpoint. But if we can't have holes, then removing the gravity line results in the indice of the checkpoint shifting down to indice 1. Then Violet is created at indice 2, and gets drawn behind the checkpoint! This is a clear illustration of changing the behavior that existed in 2.2. However, I also don't want to go back to the `active` system of having to check an attribute before operating on an entity. So... what do we do to restore the holes? Well, we don't need to have an `active` attribute, or modify any existing code that operates on entities. Instead, we can just set the attributes of the entities so that they naturally get ignored by everything that comes into contact with it. For entities, we set their invis to true, and their size, type, and rule to -1 (the game never uses a size, type, or rule of -1 anywhere); for blocks, we set their type to -1, and their width and height to 0. obj.entities.size() will no longer necessarily equal the amount of entities in the room; rather, it will be the amount of entity SLOTS that have been allocated. But nothing that uses obj.entities.size() needs to actually know the amount of entities; it's mostly used for iterating over every entity in the vector. Excess entity slots get cleaned up upon every call of mapclass::gotoroom(), which will now deallocate entity slots starting from the end until it hits a player, at which point it will switch to disabling entity slots instead of removing them entirely. The entclass::clear() and blockclass::clear() functions have been restored because we need to call their initialization functions when reusing a block/entity slot; it's possible to create an entity with an invalid type number (it creates a glitchy Viridian), and without calling the initialization function again, it would simply not create anything. After this patch is applied, entity and block indices will be restored to how they behaved in 2.2. |
||
|---|---|---|
| .. | ||
| src | ||
| .dockerignore | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CONTRIBUTORS.txt | ||
| Dockerfile | ||
| README.md | ||
| version.cmake | ||
How to Build
VVVVVV's official desktop versions are built with the following environments:
- Windows: Visual Studio 2010
- macOS: Xcode CLT, currently targeting 10.9 SDK
- GNU/Linux: CentOS 7
The engine depends solely on SDL2 and SDL2_mixer. All other dependencies are statically linked into the engine. The development libraries for Windows can be downloaded from their respective websites, Linux developers can find the dev libraries from their respective repositories, and macOS developers should compile and install from source (including libogg/libvorbis/libvorbisfile).
Steamworks support is included and the DLL is loaded dynamically, you do not need the SDK headers and there is no special Steam or non-Steam version. The current implementation has been tested with Steamworks SDK v1.46.
To generate the projects on Windows:
# Put your SDL2/SDL2_mixer folders somewhere nice!
mkdir flibitBuild
cd flibitBuild
cmake -G "Visual Studio 10 2010" .. -DSDL2_INCLUDE_DIRS="C:\SDL2-2.0.10\include;C:\SDL2_mixer-2.0.4\include" -DSDL2_LIBRARIES="C:\SDL2-2.0.10\lib\x86\SDL2;C:\SDL2-2.0.10\lib\x86\SDL2main;C:\SDL2_mixer-2.0.4\lib\x86\SDL2_mixer"
Note that on some systems, the SDL2_LIBRARIES list on Windows may need
SDL2/SDL2main/SDL2_mixer to have .lib at the end of them. The reason for this
inconsistency is unknown.
To generate everywhere else:
mkdir flibitBuild
cd flibitBuild
cmake ..
macOS may be fussy about the SDK version. How to fix this is up to the whims of however Apple wants to make CMAKE_OSX_SYSROOT annoying to configure and retain each time Xcode updates.
Including data.zip
You'll need the data.zip file from VVVVVV to actually run the game! It's available to download separately for free in the Make and Play edition of the game. Put this file next to your executable and the game should run.
This is intended for personal use only - our license doesn't allow you to actually distribute this data.zip file with your own forks without getting permission from us first. See LICENSE.md for more details. (If you've got a project in mind that requires distributing this file, get in touch!)
A Word About Compiler Quirks
(Note: This section only applies to version 2.2 of the source code, which is the initial commit of this repository. Since then, much hard work has been put in to fix many undefined behaviors. If you're compiling the latest version of the source code, ignore this section.)
This engine is super fussy about optimization levels and runtime checks. In particular, the Windows version absolutely positively must be compiled in Debug mode, with /RTC enabled. If you build in Release mode, or have /RTC disabled, the game behaves dramatically different in ways that were never fully documented (bizarre softlocks, out-of-bounds issues that don't show up in tools like Valgrind, stuff like that). There are lots of things about this old code that could be cleaned up, polished, rewritten, and so on, but this is the one that will probably bite you the hardest when setting up your own build, regardless of platform.
We hope you'll enjoy messing with the source anyway!
Love, flibit