1e9fb6aac0
Okay, so the reason why all render functions were moved to the end of the frame in #220 is because it's simpler to call two fixed functions and then a delta function instead of one fixed function, then a delta function, and then another fixed function. This is because fixed functions need special handling inside deltaloop(), and you can't simply duplicate this handling after calling a delta function. Oh, and to make matters worse, it's not always fixed-delta-fixed, sometimes (like in MAPMODE and TELEPORTERMODE) it's delta-fixed-fixed, so we'd need to handle that somehow too. The solution here is to generalize the game loop and factor out each function, instead of hardcoding it. Instead of having hardcoded case-switches directly in the loop, I made a function that returns an array of functions for a given gamestate, along with the number of functions, then the game loop processes it accordingly. In fixedloop(), it iterates over the array and executes each function until it reaches a delta function, at which point it stops. And when it reaches the end of the array, it goes back to the start of the array. But anyway, if it gets to a delta function, it'll stop the loop and finish fixedloop(). Then deltaloop() will call the delta function. And then on the next frame, the function index will be incremented again, so fixedloop() will call the fixed functions again. Actually, the previous game loop was actually made up of one big loop, with a gamestate function loop nested inside it, flanked with code that ran at the start and end of the "big loop". This would be easy to handle with one loop (just include the beginning and end functions with the gamestate functions in the array), except that the gamestate functions could suddenly be swapped out with unfocused functions (the ones that run when you unfocus the window) at any time (well, on frame boundaries, since key.isActive only got checked once, guarding the entire "inner loop" - and I made sure that changing key.isActive wouldn't immediately apply, just like the previous game loop order) - so I had to add yet another layer of indirection, where the gamestate functions could immediately be swapped out with the unfocused functions (while still running the beginning and end code, because that was how the previous loop order worked, after all). This also fixes a regression that the game loop that #220 introduced had, where if the fixed functions switched the gamestate, the game would prematurely start rendering the gamestate function of the new gamestate in the deltaframes, which was a source of some deltaframe glitches. But fixing this is likely to just as well cause deltaframe glitches, so it'd be better to fix this along with fixing the loop order, and only have one round of QA to do in the end, instead of doing one round after each change separately. Fixes #464... but this isn't the end of the patchset. There are bugs that need to be fixed, and kludges that need to be reverted. |
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| 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 2.0.14+ 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