Hi,

I installed Liquid Fun v1.0 (stable) with DEBUG build type mentioned here. However, after executing the Testbed, the program throws segmentation fault whenever I select Convex Hull test from the menu.

for javascript version.

1. add support for b2Contact.SetEnabled and b2Contact.IsEnabled

2. b2WorldManifold.GetPoint, each point data position interval should be 8 instead of 2

I found some problems with the existing bindings.

b2Body.CreateFixtureFrom(Def|Shape) accesses a global variable called world instead of the world the b2Body belongs to.

The methods GetParticleCount/GetPositionBuffer don't work quite right. Sometimes GetParticleCount is off by one, which might be because of the int/double casting. The position buffer is too small. It has the same size as the numberGetParticleCount() returns, but should be twice as large. The current bindings code seems to allocate the buffers correctly, but still results in this problem while running the code. Unfortunately, I'm not so acquainted with Emscripten so I can't figure out where the problem lies.

This wasn't compiling properly. I had originally opened https://github.com/google/liquidfun/issues/37 but then closed it as I wasn't too sure if the project was being kept up to date. Anyways, someone commented on issue 37, so creating a pull request for the fix.

So this is sort of a combo problem. First issue is that using

cmake -G Xcode

A proper Xcode project file does not build. There are a slew of errors. They range from TryCompile issues to get_filename_component called with incorrect number of arguments. If you try running cmake -G Xcode a few times, it eventually churns out an Xcode project file, which does build. However, when running 64-bit, it produces a white screen only. In 32-bit, you see the graphics, but the simulators do not run and it seems to have no keyboard input.

Alternatively, I tried to build it using build.sh. This worked. But the result was the same: Testbed ran with a pure white screen.

I'm running OSX 10.9.5. I installed XQuartz 2.7.7. My cmake version is 2.8.12.1. I am however, using Xcode 6.1. I should also note that the iOS version runs fine.

When pthread.h is not available (didn't test with an available one), the build fails with:

CMake Error at CMakeLists.txt:158 (set_target_properties): set_target_properties Can not find target to add properties to: Threads::Threads

$ANDROID_SDK_HOME should point to SDK home directory, not a directory above with hardcoded sdk directory.

Trying to build Testbed with build_apk.sh fails due to wrong path under Linux, since SDK unpacks to android-sdk-linux.

We're running physics at a fixed rate and interpolating motion between the last two physics steps. For this reason we need the current and previous position of a particle, but the self-compacting list feature causes the particle indexes to become invalid. How can we persistently track a single particle?

I have a question, is liquidfun based on some form of SPH ? After looking at source code it doesn't seem so. Is there any paper I can read about algorithms being used ?

When particles move along a fixture and one of the vertices is shared with another fixture, the particles then behave as if they collide with the second fixture.

Here's the example in full:

liquidfun_particle_bug.zip

This adds JavaScript bindings for b2Fixture.Refilter, and a JavaScript version of b2Fixture.SetFilterData. It also makes b2Body set the fixture's filter from the fixtureDef.

I applied the patch from issue 110 but now get the below error...

[ 21%] Building CXX object Box2D/CMakeFiles/Box2D.dir/Collision/b2DynamicTree.cpp.o /home/rcook/data/downloads/debian/liquidfun-1.1.0/liquidfun/Box2D/Box2D/Collision/b2DynamicTree.cpp: In constructor ‘b2DynamicTree::b2DynamicTree()’: /home/rcook/data/downloads/debian/liquidfun-1.1.0/liquidfun/Box2D/Box2D/Collision/b2DynamicTree.cpp:31:15: error: ‘void* memset(void*, int, size_t)’ clearing an object of non-trivial type ‘struct b2TreeNode’; use assignment or value-initialization instead [-Werror=class-memaccess] 31 | memset(m_nodes, 0, m_nodeCapacity * sizeof(b2TreeNode)); | ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from /home/rcook/data/downloads/debian/liquidfun-1.1.0/liquidfun/Box2D/Box2D/Collision/b2DynamicTree.cpp:20: /home/rcook/data/downloads/debian/liquidfun-1.1.0/liquidfun/Box2D/Box2D/../Box2D/Collision/b2DynamicTree.h:28:8: note: ‘struct b2TreeNode’ declared here 28 | struct b2TreeNode | ^~~~~~~~~~ cc1plus: all warnings being treated as errors make[2]: *** [Box2D/CMakeFiles/Box2D.dir/build.make:720: Box2D/CMakeFiles/Box2D.dir/Collision/b2DynamicTree.cpp.o] Error 1 make[1]: *** [CMakeFiles/Makefile2:234: Box2D/CMakeFiles/Box2D.dir/all] Error 2 make: *** [Makefile:136: all] Error 2

The examples at https://google.github.io/liquidfun/#Examples do not load currently, because as the console reports:

Mixed Content: The page at '<URL>' was loaded over HTTPS, but requested an insecure frame '<URL>'.
This request has been blocked; the content must be served over HTTPS.

• Several major fixes to BeginContact and EndContact
• Makes fixture<->particle collision distance use radius instead of diameter, and if the extra distance was intentional, the setting b2_fixtureParticleCollisionRadiusScaler gives control over this instead of it being a constant 2.
• Makes b2ParticleSystem forces clear in b2World::ClearForces(), the same way that b2Body forces are cleared. This fixes forces from being applied at only the first particleIteration.
• SolveCollision and SolveBarrier relied on (delayed) forces to be cleared immediately, in order to generate the contacts they desire, so I added m_impulseBuffer for them to use, which clears immediately.
• Fixes elastic directional bias. I believe that this bias was more noticeable with smaller time steps.

Hello everyone,

following the procedure described in the https://google.github.io/liquidfun/Building/html/md__building_linux.html page, cd liquidfun/Box2D cmake -G'Unix Makefiles' make

i get many errors, as follow:

This warning is for project developers. Use -Wno-dev to suppress it.

CMake Error at CMakeLists.txt:158 (set_target_properties): set_target_properties Can not find target to add properties to: X11::X11

CMake Error at CMakeLists.txt:158 (set_target_properties): set_target_properties Can not find target to add properties to: X11::ICE

CMake Error at CMakeLists.txt:158 (set_target_properties): set_target_properties Can not find target to add properties to: X11::SM

CMake Error at CMakeLists.txt:158 (set_target_properties): set_target_properties Can not find target to add properties to: X11::Xau

How can i fix and complete the build?

Thank you very much