spatial_hash_new

Description:

spatial hash new

SpatialHash #
An easy-to-use implementation of a Spatial Hash for Dart.
Usage #
Creating a spatial hash for Entities 10 cells wide and 10 cells tall, where each cell is 100 x 100 pixels.
import "dart:math";
import "package:spatial_hash_new/spatial_hash_new.dart";

var mySpatialHash = SpatialHash<Entity>(10, 10, 100, 100);
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Adding an entity to a spatial hash is done with add.
var entity = Entity();
mySpatialHash.add(entity, Rectangle(entity.x, entity.y, entity.width, entity.height));
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To update the position of an entity already in the spatial hash, use update.
mySpatialHash.update(entity, Rectangle(entity.x, entity.y, entity.width, entity.height));
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For removing an entity from the spatial hash, use remove.
mySpatialHash.remove(entity);
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The main utility of a spatial hash comes from the near method. This provides a set of items that
are potentially colliding with the given item.
Sample efficient collision detection. Assume you have an expensive function isOverlapping that computes
for pixel-perfect overlap between two entities of arbitrary shape. Instead of comparing each entity's shape
with every other entity's shape, you can narrow down the possible entity's to compare against using a spatial hash.
/// calls the [entity]'s `onCollide` method for each entity it is in collision with.
void detectCollisions(Entity entity) {
for (final otherEntity in mySpatialHash.near(entity)) {
if (isOverlapping(entity.shape, otherEntity.shape)) {
entity.onCollide(otherEntity);
}
}
}
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See the docs for more details and more methods. Or better yet, take a look at the source code! It's only a single dart file.
License #
This package is licensed under the MIT License.