[−][src]Crate marching_squares
This crate provides an (optionally parallelizable)
marching squares algorithm to generate isolines from
a heightmap of Vec<Vec<i16>>
values.
Adapted from https://github.com/d-dorazio/marching-squares
Warning
- The returned lines may only have two points.
Example
use marching_squares::{Field, Point}; fn main() { let width = 1600_usize; let height = 1600_usize; let n_steps = 10_usize; let mut min_val = 0; let mut max_val = 0; // Build the heightmap data (here: randomly generated from a function) let z_values = (0..height).map(|y| { (0..width).map(|x| { let x = (x as f64 - width as f64 / 2.0) / 150.0; let y = (y as f64 - height as f64 / 2.0) / 150.0; let val = ((1.3 * x).sin() * (0.9 * y).cos() + (0.8 * x).cos() * (1.9 * y).sin() + (y * 0.2 * x).cos()) as i16; min_val = min_val.min(val); max_val = max_val.max(val); val }).collect() }).collect::<Vec<Vec<i16>>>(); let field = Field { dimensions: (width, height), top_left: Point { x: 0.0, y: 0.0 }, pixel_size: (1.0, 1.0), values: &z_values, }; let step_size = (max_val - min_val) as f32 / n_steps as f32; // Generate 10 isolines // note: you could do this in parallel using rayon for step in 0..n_steps { let isoline_height = min_val as f32 + (step_size * step as f32); println!("{:#?}", field.get_contours(isoline_height as i16)); } }
Structs
Field | Raster heightmap field containing the z-values of each pixel |
Line | Line containing a |
Point | 2-dimensional Point (x, y) |