mirror of
https://github.com/TerryCavanagh/VVVVVV.git
synced 2026-01-29 09:28:15 +03:00
9f603ea3fe
Tower backgrounds have a bypos and bscroll. bypos is just the y-position of the background, and bscroll is the amount of pixels to scroll the background by on each frame, which is used to scroll it (if it's not being redrawn) and for linear interpolation. For the tower background (and not the title background), bypos is map.ypos / 2, and bscroll is (map.ypos - map.oldypos) / 2. However, usually bscroll gets assigned at the same time bypos is incremented or decremented, so you never see that calculation explicitly - except in the previous commit, where I worked out the calculation because the change in y-position isn't a known constant. Having to do all these calculations every time introduces the possibility of errors where you forget to do it, or you do it wrongly. But that's not even the worst; you could cause a linear interpolation glitch if you decide to overwrite bscroll without taking into account map.oldypos and map.ypos. So that's why I'm adding a function that automatically updates the tower background, using the values of map.oldypos and map.ypos, that is used every time map.ypos is assigned. That way, we have to write less code, you can be sure that there's no place where we forget to do the calculations (or at least it will be glaringly obvious) or we do it wrongly, and it plays nicely with linear interpolation. This also replaces every instance where the manual calculations are done with the new function.
This is the source code to VVVVVV, version 2.0+. For more context about this release, see the announcement on Terry's blog!
License
VVVVVV's source code is made available under a custom license. See LICENSE.md for more details.
In general, if you're interested in creating something that falls outside the license terms, get in touch with Terry and we'll talk about it!
Authors
- Created by Terry Cavanagh
- Room Names by Bennett Foddy
- Music by Magnus Pålsson
- Metal Soundtrack by FamilyJules
- 2.0 Update (C++ Port) by Simon Roth
- 2.2 Update (SDL2/PhysicsFS/Steamworks port) by Ethan Lee
- Beta Testing by Sam Kaplan and Pauli Kohberger
- Ending Picture by Pauli Kohberger
Versions
There are two versions of the VVVVVV source code available - the desktop version (based on the C++ port, and currently live on Steam), and the mobile version (based on a fork of the original flash source code, and currently live on iOS and Android).