How to compile Box2D in Linux?

Question

Compiling the Box2d Tesbed is supposed to be simple:

from iforce2d:

Download the Box2D source code archive from here. If you want to use the t

Answer 1

Short answer...

yes this can be built, rollback your git clone of Box2D until the build doesn't fail.

Long answer...

Seems you've encountered two separate problems:

1. Not finding the imgui.h file.
2. The introduction of nullptr to the Git source tree which requires C++11 or newer language acceptance from the compiler.

Regarding problem 1, there's been an issue filed about that back at the beginning of February 2017: issue 433. Regarding problem 2, there's also been an issue filed for this back in June 2016: issue 414.

While I did not see a resolution on GitHub for problem 1, problem 2 apparently is resolvable by applying pull request #412. You should also be able to resolve problem 2 by having your compiler accept C++11 (or newer).

As for resolving problem 1, you can roll back your git clone of Box2D until the Testbed can be built. If you rollback far enough, that should also resolve problem 2 (without needing to do anything else). Information on how to do the reversion can be found at the SO question of How to revert Git repository to a previous commit?.