192b2f2dba
While I was working on my over-30-FPS patch, I found out that the tower background in the credits scroll was being completely re-drawn every single frame, which was a bit wasteful and expensive. It's also harder to interpolate for my over-30-FPS patch. I'm guessing this constant re-draw was done because the math to get the surface scroll properly working is a bit subtle, but I've figured the precise math out! The first changes of this patch is just removing the unconditional `map.tdrawback = true;`, and having to set `map.scrolldir` everywhere to get the credits scrolling in the right direction but make sure the title screen doesn't start scrolling like a descending tower, too. After that, the first problem is that it looks like the ACTION press to speed up the credits scrolling doesn't speed up the background, too. No problem, just shove a `!game.press_action` check in `gamecompletelogic()`. However, this introduces a mini-problem, which is that NOW when you hold down ACTION, the background appears to be slowly getting out of sync with the credits text by a one-pixel-per-second difference. This is actually due to the fact that, as a result of me adding the conditional, `map.bscroll` is no longer always unconditionally getting set to 1, while `game.creditposition` IS always unconditionally getting decremented by 1. And when you hold down ACTION, `game.creditposition` gets decremented by 6. Thus, I need to set `map.bscroll` when holding down ACTION to be 7, which is 6 plus 1. Then we have another problem, which is that the incoming textures desync when you press ACTION, and when you release ACTION. They desync by precisely 6 pixels, which should be a familiar number. I (eventually) tracked this down to `map.bypos` being updated at the same time `map.bscroll` is, even though `map.bypos` should be updated a frame later AFTER updating `map.bscroll`. So I had to change the `map.bypos` update in `gamecompleteinput()` and `gamecompletelogic()` to be `map.bypos += map.bscroll;` and then place it before any `map.bscroll` update, thus ensuring that `map.bscroll` updates exactly one frame before `map.ypos` does. I had to move the `map.bypos += map.bscroll;` to be in `gamecompleteinput()`, because `gamecompleteinput()` comes first before `gamecompletelogic()` in the `main.cpp` game loop, otherwise the `map.bypos` update won't be delayed by one frame for when you press ACTION to make it go faster, and thus cause a desync when you press ACTION. Oh and then after that, I had to make the descending tower background draw a THIRD row of incoming tiles, otherwise you could see some black flickering at the bottom of the screen when you held down ACTION. All of this took me way too long to figure out, but now the credits scroll works perfectly while being more optimized. |
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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
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