Added new filtering implementation to documentation

Docs/Architecture.md

@@ -312,7 +312,7 @@ Soft bodies are currently in development, please note the following:
 
 When bodies are added to the PhysicsSystem, they are inserted in the broad phase ([BroadPhaseQuadTree](@ref BroadPhaseQuadTree)). This provides quick coarse collision detection based on the axis aligned bounding box (AABB) of a body.
 
-The broad phase is divided in layers, each layer has a AABB quad tree associated with it. When constructing the physics system an [ObjectVsBroadPhaseLayerFilter](@ref ObjectVsBroadPhaseLayerFilter) and [ObjectLayerPairFilter](@ref ObjectLayerPairFilter) need to be provided. These determine which object layers collide with which broad phase/object layer. If two layers don't collide, the objects inside those layers cannot collide. A standard setup would be to have a MOVING and a NON_MOVING layer, where NON_MOVING doesn't collide with NON_MOVING and all other permutations collide. This ensures that all static bodies are in one tree (which is infrequently updated) and all dynamic bodies are in another (which is updated every simulation step). It is possible to create more layers like a BULLET layer for high detail collision bodies that are attached to lower detail simulation bodies, the MOVING layer would not collide with the BULLET layer, but when performing e.g. weapon collision queries you can quickly test against only objects in the BULLET layer. In general you can have as many object layers as you want, but you should only have a few broad phase layers as there is overhead in maintaining many different broad phase trees.
+The broad phase is divided in layers (BroadPhaseLayer), each layer has an AABB quad tree associated with it. When constructing the physics system an ObjectVsBroadPhaseLayerFilter, ObjectVsBroadPhaseLayerFilter and BroadPhaseLayerInterface need to be provided. These determine which object layers ([ObjectLayer](@ref ObjectLayer)) collide with which broad phase/object layer. If two layers don't collide, the objects inside those layers cannot collide. A standard setup would be to have a MOVING and a NON_MOVING layer, where NON_MOVING doesn't collide with NON_MOVING and all other permutations collide. This ensures that all static bodies are in one tree (which is infrequently updated) and all dynamic bodies are in another (which is updated every simulation step). It is possible to create more layers like a BULLET layer for high detail collision bodies that are attached to lower detail simulation bodies, the MOVING layer would not collide with the BULLET layer, but when performing e.g. weapon collision queries you can quickly test against only objects in the BULLET layer. In general you can have as many object layers as you want, but you should only have a few broad phase layers as there is overhead in maintaining many different broad phase trees.
 
 Since we want to access bodies concurrently the broad phase has special behavior. When a body moves, all nodes in the AABB tree from root to the node where the body resides will be expanded using a lock-free approach. This way multiple threads can move bodies at the same time without requiring a lock on the broad phase. Nodes that have been expanded are marked and during the next physics step a new tight-fitting tree will be built in the background while the physics step is running. This new tree will replace the old tree before the end of the simulation step. This is possible since no bodies can be added/removed during the physics step.
 
@@ -338,6 +338,10 @@ As touched upon in the Broad Phase section, there are various collision filterin
 
 The filter functions are listed in the order they're called. To avoid work, try to filter out collisions as early as possible.
 
+For convenience two filtering implementations are provided:
+* ObjectLayerPairFilterTable, ObjectVsBroadPhaseLayerFilterTable and BroadPhaseLayerInterfaceTable: These three implement collision layers as a simple table. You construct ObjectLayerPairFilterTable with a fixed number of object layers and then call ObjectLayerPairFilterTable::EnableCollision or ObjectLayerPairFilterTable::DisableCollision to selectively enable or disable collisions between layers. BroadPhaseLayerInterfaceTable is constructed with a number of broad phase layers. You can then map each object layer to a broad phase layer through BroadPhaseLayerInterfaceTable::MapObjectToBroadPhaseLayer.
+* ObjectLayerPairFilterMask, ObjectVsBroadPhaseLayerFilterMask and BroadPhaseLayerInterfaceMask: These split an ObjectLayer in an equal amount of bits for group and mask. Two objects collide if (object1.group & object2.mask) != 0 && (object2.group & object1.mask) != 0. This behavior is similar to e.g. Bullet. In order to map groups to broad phase layers, you call BroadPhaseLayerInterfaceMask::ConfigureLayer for each broad phase layer. You determine which groups can be put in that layer and which group must be excluded from that layer. E.g. a broad phase layer could include everything that has the STATIC group but should exclude everything that has the SENSOR group, so that if an object has both STATIC and SENSOR bits set, this broad phase layer will not be used. The broad phase layers are checked one by one and the first one that meets the condition is the one that the body will be put in. If you use this implementation, consider setting the cmake option OBJECT_LAYER_BITS to 32 to get a 32-bit ObjectLayer instead of a 16-bit one.
+
 ## The Simulation Step
 
 The simulation step [PhysicsSystem::Update](@ref PhysicsSystem::Update) uses jobs ([JobSystem](@ref JobSystem)) to perform the needed work. This allows spreading the workload across multiple CPU's. We use a Sequential Impulse solver with warm starting as described in [Modeling and Solving Constraints - Erin Catto](https://box2d.org/files/ErinCatto_ModelingAndSolvingConstraints_GDC2009.pdf)

Docs/ReleaseNotes.md

@@ -5,6 +5,7 @@ For breaking API changes see [this document](https://github.com/jrouwe/JoltPhysi
 ## Unreleased changes
 
 ### New functionality
+* Created an object layer filter implementation that is similar to Bullet's group & mask filtering, see ObjectLayerPairFilterMask.
 * Ability to enable gyroscopic forces on bodies to create the [Dzhanibekov effect](https://en.wikipedia.org/wiki/Tennis_racket_theorem).
 * Swing limits do not need to be symmetrical anymore for SixDOFConstraints. This requires using the new pyramid shaped swing limits (ESwingType::Pyramid). SwingTwistConstraints still requires symmetrical limits but can use the pyramid swing limits too. These are cheaper to evaluate but are less smooth.
 * Twist limits no longer need to be centered around zero for SixDOFConstraints and SwingTwistConstraints, any value between -PI and PI is supported now.