Optimization of a GC language, any ideas?

Question

I\'m a pretty big newbie when it comes to optimization. In the current game I\'m working on I\'ve managed to optimize a function and shave about 0.5% of its CPU load and tha

Answer 1

I suppose you follow the performance hints in http://farseerphysics.codeplex.com/documentation already :-)

• The most important thing seems to be to reduce complexity for the collision detection calculations, i.e. not the visual but the colliding shapes. In Unijty3D they are called colliders and you can attach a simple cube as a collider to a complex human body. I don't know anything about Fareer but they probably have similar concept (is it called body?).

  If possible, try to replace your main character or other complex objects by easy cubes and check if fps raises.

• Compiler switches sometimes leverage performance. Be really sure that there are no debug settings activated (I got up to 30 times slower code in a C++ library project). Ensure that armv7 optimisation is turned on and -O3 or -Os

• Watch out for logging statements as they are extremely expensive on iPhone

[Update:]

• Try to decrease the number of actively calculated AABBs just to find out which part of the physics engine causes the trouble. If it's the pure number follow FFox' advice.

• What is about other platforms? Where did you perform the testing during the development phase, on simulator? Which one? Any chance to get it running on Android or Android simulator or Windows Phone? This would give you a hint if it is an iPhone specific problem.

• Ah, I just saw that ExEn still is in pre-release state and the final will be launched on July 21th as OS. IMO this changes the situation: If your App is running fine on some other comparable platform, then just wait for the release and give it a new try. Chances are pretty well that there is still debugging code in the pre-release you are working on.

Answer 2

First of all, love your game on Windows Phone 7!

Secondly, I don't see anything out of the ordinary in your profiler output. I did a quick and dirty performance analysis of the Farseer engine once (running in .net) and came up with similar results. It almost looks like you have a slowdown that is proportional across the board and may be due to mono itself.