The 1.1.0 release of LiquidFun adds support for new platforms, speeds-up
the simulation, and documents the particle simulation algorithm with a fun,
visual presentation. Some highlights:
- iOS support.
- Improved Java support via more SWIG bindings.
- An Inside LiquidFun presentation explaining the particle simulation
- ARM optimizations using NEON.
- Stability and collision improvements to the particle simulation.
- More ways to inspect particle contacts.
- A LiquidFun logo to use in your splash screens and documentation, if you
The API Modifications are minimal in this release,
but please review them carefully before upgrading your project.
LiquidFun now supports Mac, Windows, Linux, Android, iOS, and browsers. Note
that LiquidFun code is portable C++98, so you should be able to compile it for
other platforms too.
LiquidFun 1.1.0 is based on Box2D revision 280, the 2.3.0 release of
- Added iOS XCode projects for the Testbed application and EyeCandy demo.
- Added b2ParticleSystem::SplitParticleGroup, which finds disjoint blobs of
particles, and puts each into its own b2ParticleGroup.
- Added several accessor functions that use only int32s, float32s, and void
pointers. These accessors are wrapped in the
LIQUIDFUN_EXTERNAL_LANGUAGE_API preprocessor define. They enable binding
with other languages--for example, via SWIG.
- Particle indices can be represented with 16-bits instead of 32-bits. This
is a nice optimization if you know you will have less than 32k particles
- b2ParticleSimulation::UpdateContacts has been rewritten to take advantage
of NEON SIMD. The original implementation remains, for reference, and for
platforms that do not support NEON SIMD. The NEON SIMD version requires
16-bit particle indices.
- b2ParticleContact's members are now accessed via Get and Set functions.
- b2ParticleSystemDef now has members for strictContactCheck, density,
gravityScale, radius, and maxCount. You can still set these values after
b2ParticleSystem creation, however, for example via
- Added b2ParticleSystem::GetAllParticleFlags,
b2ParticleGroup::GetAllParticleFlags, which OR-together all the flags in
a particle system or group.
- Expose the contact weight buffer. The weight represents how closely two
- Expose particle pairs and triads for reading. These arrays indicate which
particles are interacting.
- Added b2ParticleGroup::GetLinearVelocityFromWorldPoint, which returns the
average velocity of a particle group with respect to a position. The
position is used to calculate the angular velocity of the group.
- Added b2World::CalculateReasonableParticleIterations to give a good
estimate of the number of particle iterations you should pass into
- Multiple particle systems.
- New particle behaviors: barrier, static-pressure, and repulsive.
- Particle lifetimes.
- Detection of stuck particles.
- The ability to apply forces and impulses to particles.
- Java support via SWIG.
- A host of new demos: inside the existing Testbed application, and gorgeous
new "EyeCandy" demo for Android.
- Added option to substep particle simulation independently of
- Added barrier particles which can be used to prevent particle tunneling
due to large particle velocities or simulation steps.
- Added static pressure particles to reduce compression of fluids.
- Added repulsive particles to separate particle groups from each other.
- Added support for multiple independent particle systems.
- Added option to create particles in an existing particle group.
- Added option to detect stuck particles.
- Added option to pause particle simulations. Paused simluations don't
consume cycles in b2World::Step.
- Added option to enable a more strict check for Particle/Body interactions
in cases where complex world geometry may cause false positive contacts.
- Added option to call a contact listener or filter on particle / fixture
or particle / particle interactions.
- Added the ability to apply forces and impulses to particles.
- Added "EyeCandy" sample to demonstrate different particle rendering methods
- Added "Sparky", "Sandbox" and "Soup Stirrer" tests to the Testbed example
to demonstrate particle and rigid body interaction.
- Added "Ramp", "Pointy", and "AntiPointy" tests to the Testbed example to
illustrate the difference with strict contact checking.
- Added "Maxwell" test to the Testbed to demonstrate the direct modification
of particle velocities.
- Added "Fracker" test to demonstrate particle viscous fluids and particle
- Added "Multiple Systems" test to the Testbed to demonstrate multiple
- Added Java Native Interface support via SWIG. It covers a subset of the
- Added the ability to pass a list of shapes to be passed in for
b2Draw::e_particleBitflag now enables/disables
b2World::DrawDebugData()drawing the particle system.
To render the particle system using
b2Draw::e_particleBit flag must be set on the
b2Draw object passed
b2World::SetDebugDraw(). It is possible to set flags on
Release 0.9.0 unconditionally called
- Building LiquidFun on Linux, using
cmake -G"Unix Makefiles", now places
output files in a build type sub-directory.
For example, the output executable of the Testbed example is now
written to Box2D/Testbed/Release/Testbed when building using the Release
- Multiple independent particle systems can now exist, each with its own
physical coefficients. Previously, only one particle system existed, and
it always existed. Use b2World::CreateParticleSystem to create particle
systems, and b2World::DestroyParticleSystem to destroy them.
- b2DestructionListener::SayGoodbye, b2QueryCallback::ReportParticle, and
b2RayCastCallback::ReportParticle each now takes a b2ParticleSystem pointer
as its first parameter. This change is necessary since multiple particle
systems can now exist.
- The particle system API has moved from b2World to b2ParticleSystem.
For example, b2ParticleSystem::DestroyParticlesInShape replaces
b2World::DestroyParticlesInShape. You can use
b2World::CreateParticleSystem or b2World::GetParticleSystemList() to
acquire references to b2ParticleSystem.
- Removed "Particle" from many of the functions in the particle system API.
The word is redundant now that the API is under b2ParticleSystem. The API
now has the following naming convention:
- Each function that takes a particle index or handle has a "Particle"
component (e.g. "SetParticle").
- Each function that operates on the entire system has no "Particle"
component (e.g. "SetRadius").
``` GetParticleMaxCount ==> GetMaxParticleCount SetParticleMaxCount ==> SetMaxParticleCount GetParticleDensity ==> GetDensity SetParticleDensity ==> SetDensity SetParticleGravityScale ==> SetGravityScale GetParticleGravityScale ==> GetGravityScale SetParticleDamping ==> SetDamping GetParticleDamping ==> GetDamping GetParticleStaticPressureIterations ==> GetStaticPressureIterations SetParticleStaticPressureIterations ==> SetStaticPressureIterations SetParticleRadius ==> SetRadius GetParticleRadius ==> GetRadius GetParticlePositionBuffer ==> GetPositionBuffer GetParticlePositionBuffer ==> GetPositionBuffer GetParticleVelocityBuffer ==> GetVelocityBuffer GetParticleVelocityBuffer ==> GetVelocityBuffer GetParticleColorBuffer ==> GetColorBuffer GetParticleColorBuffer ==> GetColorBuffer GetParticleGroupBuffer ==> GetGroupBuffer GetParticleGroupBuffer ==> GetGroupBuffer GetParticleUserDataBuffer ==> GetUserDataBuffer GetParticleUserDataBuffer ==> GetUserDataBuffer GetParticleFlagsBuffer ==> GetFlagsBuffer SetParticleFlagsBuffer ==> SetFlagsBuffer SetParticlePositionBuffer ==> SetPositionBuffer SetParticleVelocityBuffer ==> SetVelocityBuffer SetParticleColorBuffer ==> SetColorBuffer SetParticleUserDataBuffer ==> SetUserDataBuffer GetParticleContacts ==> GetContacts GetParticleContactCount ==> GetContactCount GetParticleBodyContacts ==> GetBodyContacts GetParticleBodyContactCount ==> GetBodyContactCount DestroyParticlesInGroup ==> DestroyParticles (moved to b2ParticleGroup) ```
b2DestructionListenerParticleto be consistent with other particle flag
- Better particle-behavior stability.
- Integrated Box2D 2.3.0 release from Box2D revision 280.
- Reduced the size of particles in Testbed particle tests to be consistent
with the size of rigid bodies.
- Improved damping force to prevent particle explosions.
b2Timerbug that occurs when the usec component wraps.
b2Statto calculate min/max/mean of a set of samples, and
integrated this functionality into Testbed to measure performance.
- Fixed memory leaks of large blocks allocated by b2BlockAllocator.
- Fixed incorrect stack-capacity calculation in b2VoronoiDiagram.
- Added operators to
- Improved parameter and option selection in Testbed with the fullscreen UI.
- Cleaned up statistics display in Testbed.
- Fixed depth-buffer allocation when creating an empty particle group.
- Added build step to unit-test execution scripts.
- Added generation of code coverage report for unit-tests.
- Added a script to clean up temporary cmake files.
- Increased warning level and enabled conversion of warnings to errors.
- Added unit-test for b2IsValid().
b2World::QueryShapeAABB()convenience function to query the world
for objects in the AABB which encloses a shape.
- Inlined some simple b2ParticleSystem and b2ParticleGroup functions.
- Allowed particle systems to be culled from b2World::QueryAABB and
- Added callbacks so an application can override b2Alloc() and b2Free()
without modifying the library.
- Added valgrind support to unit-test runner on Linux / OSX.
- Added cygwin wrapper script for build.bat and build_android.bat on Windows.
- Added option to archive build artifacts from build scripts.
- Changed Android C++ runtime library to gnustl_static.
The initial release of LiquidFun is available for download from the
0.9.0 release release page.
- Particle system added to Box2D.
- Example applications ported to Android.
- No changes to the Box2D 2.3.0 pre-release API.