5e94239967
This patch optimizes the loop used to limit the framerate in 30-FPS-only mode so that it uses SDL_Delay() instead of an accumulator. This means that the game will take up less CPU power in 30-FPS-only mode. This also means that the game loop code has been simplified, so there's only two while-loops, and only two places where game.over30mode is checked, thus leading to easier-to-understand logic. Using an accumulator here would essentially mean busywaiting until the 34 millisecond timer was up. (The following is just what leo60228 told me.) Busywaiting is bad because it's inefficient. The operating system assumes that if you're busywaiting, you're performing a complex calculation and handles your process accordingly. And this is why sleeping was invented, so you could busywait without taking up unnecessary CPU time. |
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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