Regular Grid

A small utility library for working with regular rectilinear grids.

Features

• Simple but complete 2D regular grid index class with arithmetic operators, equality and compatibility with other point or vector like classes.

Planned Features

• 3D regular grid index class.
• 2D and 3D grid array classes.

Getting Started

GridIndex2 implements dart:math's Point<int>'s interface. All constructors, operators and methods that would normally be expected to take another GridIndex2 actually take a Point<int>.

import 'dart:math';
...
Point<int> point = new Point<int>(-7, 9);
GridIndex2 index = new GridIndex2.copy(point);
index.copyFrom(point);
index.add(point);

A GridIndex2 may be constructed or copied from any object that has x and y properties of type num, and has four options for transforming those properties into int values: truncate, floor, ceil and round - in each case the appropriate conversion method is called on each property.

For instance, a GridIndex2 may be constructed and copied from a vector_math Vector2.

import 'package:vector_math';
...
Vector2 vector = new Vector2(-7.7, 9.9)
GridIndex2 index = new GridIndex2.fromDynamic(vector, floor); // x=-8, y=9
index.copyFromDynamic(vector, truncate); // x=-7, y=9

Component-wise equality is provided. Again operator== actually takes a Point<int>. Note that invoking Point<int>'s equality operator on a GridIndex2 also works as expected.

GridIndex2 index1 = new GridIndex2(-7, 9);
GridIndex2 index2 = new GridIndex2(-7, 9);
GridIndex2 index2 = new GridIndex2(-14, 18);
Point<int> point = new Point<int>(-7, 9);

index1 == index2; // true
index1 == index1; // true
index1 == index3; // false
index1 == point; // true
point  == index1; // true

The hashCode property is implemented (using Quiver's hash functions), so instances may be used as a Map index etc.

var map = new Map<GridIndex2, ...>();