[−][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.
Uses no_std, but uses the alloc crate.
Please see the broccoli-book which is a work in-progress high level explanation and analysis
of this crate.
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.
Screenshot
Screenshot from the broccoli_demo inner project from the github repo of this crate.
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 book mentioned in the overview section.
(Rect<N>,&mut T)*recommended(Rect<N>,T)&mut (Rect<N>,T)
User Protection
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
Usage Guidlines
The AABB struct that the user must use is from the axgeom crate.
If you insert aabb's with zero width or zero height, it is unspecified behavior (but still safe). It is expected that all elements in the tree take up some area. This is not inteded to be used as a "point" tree. Using this tree for a point tree would be inefficient anyway since the data layout assumes there is a aabb, which is composed of 4 numbers when a point would be just 2.
That said, an aabb is composed of half-open ranges [start,end). So one could simulate a "point", by putting in a very small epsilon value to ensure that end>start.
Unsafety
Raw pointers are used for the container types in the container module and for caching the results of finding colliding pairs.
MultiRectMut 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.
Re-exports
pub extern crate axgeom; |
Modules
| analyze | Contains code to manipulate the dinotree data structure and some of its query algorithms to help analyze and measure their performance. |
| assert | |
| builder | |
| collections | Overview |
| node | Contains node-level building block structs and visitors used for a Tree. |
| par | Contains code to write generic code that can be run in parallel, or sequentially. The api is exposed in case users find it useful when writing parallel query code to operate on the tree. |
| pmut | Provides a mutable pointer type that is more restrictive that &mut T, in order to protect tree invariants. PMut is short for protected mutable reference. |
| prelude | |
| query | Module contains query related structs. |
| util | Generic slice utillity functions. |
Structs
| BBox | A bounding box container object that implements Aabb and HasInner.
Note that |
| CollidingPairs | |
| Tree | The data structure this crate revoles around. |
Traits
| Aabb | Trait to signify that this object has an axis aligned bounding box. get() must return a aabb with the same value in it while the element is in the dinotree. This is hard for the user not to do, this the user does not have &mut self, and the aabb is implied to belong to self. But it is still possible through the use of static objects or RefCell/ Mutex, etc. Using this type of methods the user could make different calls to get() return different aabbs. This is unsafe since we allow query algorithms to assume the following: If two object's aabb's don't intersect, then they can be mutated at the same time. |
| HasInner | Trait exposes an api where you can return a read-only reference to the axis-aligned bounding box and at the same time return a mutable reference to a seperate inner section. |
| Num | The underlying number type used for the dinotree. 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 | Constructor of the default axis type. Needed since you cannot construct from type alias's. |
| new | Examples |
| new_par | Examples |
| with_axis | Examples |
| with_axis_par | Examples |
Type Definitions
| DefaultA | The type of the axis of the first node in the Tree. If it is the y axis, then the first divider will be a horizontal line, since it is partioning space based off of objects y value. |