Treemap

Implements the Squarified Treemap algorithm published by Mark Bruls, Kees Huizing, and Jarke J. van Wijk.

The Squarified Treemap algorithm paper can be found here: https://www.win.tue.nl/~vanwijk/stm.pdf

Uses

Suppose we have a rectangle with a width of 6 and a height of 4, and furthermore suppose that this rectangle must be subdivided in seven rectangles with areas 6, 6, 4, 3, 2, 2, and 1. The standard treemap algorithm uses a simple approach: The rectangle is subdivided either horizontally or vertically. Thin rectangles emerge, with aspect ratios of 16 and 36, respectively.

In other words, it'll look something like this:

text +------+------+----+---+--+-+ | | | | | | | | | | | | | | | 6 | 6 | 4 | 3 | 2|1| | | | | | | | +------+------+----+---+--+-+

The Squarified Treemap algorithm tesselates a rectangle recursively into rectangles, such that their aspect ratios approach 1 as close as possible.

text +-------------+-----+-----+--+ | | 2 | 2 | 1| | 6 +-----+-+---+--| |-------------+ | | | | | | | 6 | 4 | 3 | +-------------+-------+------+

This can be useful for a variety of purposes:

• visualizing hierarchal structures, such as showing how much space each directory uses in a file drive
• generating a floor map given an area on how each room should be subdivided (bathrooms would need a smaller amount of space than a living room, for example)

Example

This example will tesselate a rectangle with a width of 6 and a height of 4 with seven rectangles with areas 6, 6, 4, 3, 2, 2, and 1, then display each rectangle's top-left corner's x and y position within the larger rectangle (the bounds), as well as their respective height and width.

To start, generate a new project:

console $ cargo new --bin treemap-example Created binary (application) `treemap-example` package

Add treemap to Cargo.toml:

toml [dependencies] treemap = "0.2.0"

Then, in src/main.rs:

```rust extern crate treemap;

use treemap::{MapItem, Mappable, Rect, TreemapLayout};

fn main() { let mut layout = TreemapLayout::new(); let bounds = Rect::newfrompoints(0.0, 0.0, 6.0, 4.0); let mut items: Vec> = vec![ Box::new(MapItem::newwithsize(6.0)), Box::new(MapItem::newwithsize(6.0)), Box::new(MapItem::newwithsize(4.0)), Box::new(MapItem::newwithsize(3.0)), Box::new(MapItem::newwithsize(2.0)), Box::new(MapItem::newwithsize(2.0)), Box::new(MapItem::newwithsize(1.0)), ];

layout.layout_items(&mut items, bounds);

for item in items {
    let item_bounds = item.get_bounds();
    println!("x={} y={} w={} h={}", i, item_bounds.x, item_bounds.y, item_bounds.w, item_bounds.h);
    println!("------");
}

} ```