I looked at an open source project(HedgeWars) that was built using many programming languages such as C++ and Java. While I was looking through the code, I couldn't help noticing that all the math and physics were gone from the Java code.

HedgeWars

I imported the project file called "SDL-android-project" which was a sub folder to "android build" and project files.

My question is where is all the math and physics inside the code? Do I have to look at the C++ code in order to see it?

I think Hedgewars was originally programmed in C++ but the files are confusing be because of its size and the fact that it has several programming languages inside.