[−][src]Crate broccoli
Broccoli is a broadphase collision detection library. The base data structure is a hybrid between a KD Tree and Sweep and Prune.
Data Structure
Using this crate, the user can create three flavors of the same fundamental data structure. The different characteristics are exlored more in depth in the broccoli book
(Rect<N>,&mut T)Semi-direct(Rect<N>,T)Direct&mut (Rect<N>,T)Indirect
There are so many Tree types which one do I use?
The container module lists the tree types and they are all described there, but the
TL;DR is use Tree and fill it with BBox<N,&mut T> unless you want
to use functions like collect_colliding_pairs.
In which case use TreeRefInd.
Checkout the github examples.
Parallelism
Parallel versions of construction and colliding pair finding functions
are provided. They use rayon under the hood which uses work stealing to
parallelize divide and conquer style recursive functions.
Floating Point
The Num trait used for the aabbs inserted into the tree must implement Ord,
thus you can't add f32 or f64. However, you can use the ordered_float crate, which
is re-exported at [axgeom::ordered_float].
The broccoli book mentioned above compares performance. For best performance,
you will likely want to convert the floats to integers anyway.
Protecting Invariants Statically
A lot is done to forbid the user from violating the invariants of the tree once constructed
while still allowing them to mutate parts of each element of the tree. The user can mutably traverse
the tree but the mutable references returns are hidden behind the PMut<T> type that forbids
mutating the aabbs.
Unsafety
Raw pointers are used for the container types in the container module and for caching the results of finding colliding pairs.
query::Queries::multi_rect uses unsafety to allow the user to have mutable references to elements
that belong to rectangle regions that don't intersect at the same time. This is why
the Aabb trait is unsafe.
Name
If you shorten "broadphase collision" to "broad colli" and say it fast, it sounds like broccoli. Broccoli also have tree like properties and broccoli uses a tree data structure.
Re-exports
pub use axgeom; |
pub use compt; |
pub use rayon; |
Modules
| analyze | Contains code to help analyze the |
| container | Container trees that deref to |
| convert | Helper functions to convert aabbs in floats to integers |
| node | Contains node-level building block structs and visitors used for a |
| pmut | Provides a mutable pointer type that is more restrictive that |
| prelude | The broccoli prelude. |
| query | Module contains query related structs. |
Structs
| BBox | A bounding box container object that implements |
| Range | A 1D range. Internally represented as start and end. (as opposed to a start and length) This means that subdivision does not result in any floating point calculations. The start value must be <= the end value. There is no protection against "degenerate" Ranges where start>end. Behavior of any of the functions with degenrate Ranges is unspecified. |
| Rect | An axis aligned rectangle. Stored as two Ranges. It is a semi-closed rectangle. A point is considered inside the rectangle if it is in [start,end) for both x and y. |
| Tree | The data structure this crate revoles around. |
Traits
| Aabb | Trait to signify that this object has an axis aligned bounding box.
|
| Num | The underlying number type used for the tree. It is auto implemented by all types that satisfy the type constraints. Notice that no arithmatic is possible. The tree is constructed using only comparisons and copying. |
Functions
| bbox | Shorthand constructor of |
| default_axis | Returns the default axis type. |
| new | Create a |
| new_par | Create a |
| rect | Convenience function to create a Rect. |
| with_axis | Create a |
| with_axis_par | Create a |
Type Definitions
| DefaultA | The default starting axis of a |