77a636509b
The onroof/onground attributes are used to determine if the player is standing on a surface and is eligible to flip. Most notably, it is an integer and not a boolean, and it starts at 2, giving the player 2 frames to edge-flip, i.e. they can still flip 2 frames after walking off an edge. However, these attributes are unnecessarily reassigned in movingplatformfix() (which is the function that deals exclusively with vertically-moving platforms; horizontal moving platforms get their own hormovingplatformfix()). Whoever wrote this misunderstood what onroof/onground meant; they thought that they were booleans, and so set them to true, instead of the proper value of 2. This ends up setting onroof/onground to 1 instead of 2, causing a discrepancy with vertical moving platforms and the rest of the surfaces in the game. The bigger mistake here is duplicating code that never needed to be duplicated. The onroof/onground assignment in gamelogic() works perfectly fine for vertical moving platforms. Indeed, after testing it with libTAS, I can confirm that removing the duplicate assignments restores being able to edge-flip off of moving platforms with 2 frames of leeway, instead of only 1 frame. It also doesn't change how long it takes for the onroof/onground to get set when the player is recognized as standing on a vertically-moving platform, either. And so, it's better to not duplicate this code, because when you duplicate it you run the risk of making a mistake, as I just demonstrated. |
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| src | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CONTRIBUTORS.txt | ||
| README.md | ||
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