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This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -1,8 +1,16 @@ /* This is a naive implementation of Jonathan McCabe's elaboration of * Alan Turing's model of morphogenesis, as described here: * http://www.jonathanmccabe.com/Cyclic_Symmetric_Multi-Scale_Turing_Patterns.pdf */ extern crate rand; use rand::Rng; use std::env; use std::io::Write; use std::ops::{Index,IndexMut}; use std::fs; use std::path::Path; struct Config { inner_size: usize, @@ -23,12 +31,16 @@ fn clamp(low: f32, high: f32, num: f32) -> f32 { } } /* We're going to, for simplicity, assume that images are always * square, so an image is a size along one dimension plus a vector * of floats. */ struct Image { sz: usize, px: Vec<f32>, } impl Image { /* Our constructors are straightforward */ fn new(sz: usize) -> Image { let mut v = Vec::new(); for _ in 0..(sz*sz) { @@ -46,21 +58,41 @@ impl Image { Image { sz: sz, px: v } } /* This probably isn't super useful here, but it would be * if we kept the Image representation appropriately * private and encapsulated. */ fn dim(&self) -> usize { self.sz } fn in_bounds(&self, x: usize, y: usize) -> bool { x < self.sz && y < self.sz } /* We're printing as a pgm file, which is straightforward, * especially as this ignores errors entirely: */ fn print(&self, mut f: fs::File) { /* A header, which is just the text P2 */ let _ = writeln!(f, "P2"); /* The width and height in pixels: */ let _ = writeln!(f, "{} {}", self.dim(), self.dim()); /* and the maximum greyscale value. I'm just using 128 * for no real reason. */ let _ = writeln!(f, "128"); /* And then we just convert all the floats to ints in the * range [0,128] and we're good. We don't need to use a * newlines like we do, but it's nice for debugging. */ for x in 0..self.dim() { for y in 0..self.dim() { let _ = writeln!(f, "{} ", (self[(x,y)] * 128.0).floor()); } let _ = writeln!(f, ""); } } } /* We also want to index our images using pairs, so we can implement * the indexing traits to make our code nicer. */ impl Index<(usize, usize)> for Image { type Output = f32; @@ -75,28 +107,40 @@ impl IndexMut<(usize, usize)> for Image { } } /* The actual step-running is pretty simple: */ fn run_step(old: &Image, new: &mut Image, conf: &Config) { /* We loop over every pixel in the image... */ for x in 0..conf.img_size { for y in 0..conf.img_size { /* And compute the average value of two neighborhoods: a * smaller one... */ let near = gather_neighbors(old, (x, y), conf.inner_size); /* And a larger one. */ let far = gather_neighbors(old, (x, y), conf.outer_size); /* Depending on which one is bigger, we either add or subtract * from the existing value of the pixel. */ let dx = if near < far { conf.incr_amt } else { conf.decr_amt }; /* And we clamp the range to [0.0,1.0] for good measure. */ new[(x, y)] = clamp(0.0, 1.0, old[(x, y)] + dx); } } } /* Our neighborhood is based on Manhattan distance. We could futz with this * to create different, interesting patterns, too. */ fn gather_neighbors(img: &Image, (x, y): (usize, usize), n: usize) -> f32 { /* We keep a running average... */ let mut amt = 0.0; let mut tot = 0.0; /* This is for going back and forth between signed and unsigned types. * There is almost certainly a better way of doing this and I don't * really care. */ let ns = n as isize; for i in -ns..ns { for j in -ns..ns { let xn = (i + x as isize) as usize; let yn = (j + y as isize) as usize; if img.in_bounds(xn, yn) { amt += img[(xn,yn)]; tot += 1.0; } @@ -106,29 +150,37 @@ fn gather_neighbors(img: &Image, (x, y): (usize, usize), n: usize) -> f32 { } fn main() { /* We can vary these parameters here if we want. */ let conf = Config { inner_size: 18, outer_size: 12, incr_amt: 0.05, decr_amt: -0.05, steps: 100, img_size: 256, }; /* Take the filename to write to. */ let filename = match env::args().nth(1) { Some(n) => n, None => panic!("Usage: [target]"), }; println!("Printing to {:?}", filename); /* Run the above step for some number of times */ let final_image = { let mut old = Image::new_rand(conf.img_size); let mut new = Image::new(conf.img_size); for _ in 0..conf.steps { run_step(&old, &mut new, &conf); std::mem::swap(&mut new, &mut old); } new }; /* ...and print to the specified file */ match fs::File::create(Path::new(&filename)) { Ok(file) => final_image.print(file), _ => panic!("Unable to open file."), }; } -
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This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,134 @@ extern crate rand; use rand::Rng; use std::io::Write; use std::ops::{Index,IndexMut}; use std::fs; struct Config { inner_size: usize, outer_size: usize, incr_amt: f32, decr_amt: f32, steps: usize, img_size: usize, } fn clamp(low: f32, high: f32, num: f32) -> f32 { if num < low { low } else if num > high { high } else { num } } struct Image { sz: usize, px: Vec<f32>, } impl Image { fn new(sz: usize) -> Image { let mut v = Vec::new(); for _ in 0..(sz*sz) { v.push(0.0); } Image { sz: sz, px: v } } fn new_rand(sz: usize) -> Image { let mut rng = rand::thread_rng(); let mut v = Vec::new(); for _ in 0..(sz*sz) { v.push(rng.gen()); } Image { sz: sz, px: v } } fn dim(&self) -> usize { self.sz } fn print(&self, mut f: fs::File) { writeln!(f, "P2\n{} {}\n128", self.dim(), self.dim()); for x in 0..self.dim() { for y in 0..self.dim() { writeln!(f, "{} ", (self[(x,y)] * 128.0).floor()); } writeln!(f, ""); } } } impl Index<(usize, usize)> for Image { type Output = f32; fn index<'a>(&'a self, (x, y): (usize, usize)) -> &'a f32 { &self.px[x * self.sz + y] } } impl IndexMut<(usize, usize)> for Image { fn index_mut<'a>(&'a mut self, (x, y): (usize, usize)) -> &'a mut f32 { &mut self.px[x * self.sz + y] } } fn run_step(old: &Image, new: &mut Image, conf: &Config) { for x in 0..conf.img_size { for y in 0..conf.img_size { if gather_neighbors(old, (x, y), conf.inner_size) > gather_neighbors(old, (x, y), conf.outer_size) { new[(x,y)] = clamp(0.0, 1.0, old[(x,y)] + conf.incr_amt) } else { new[(x,y)] = clamp(0.0, 1.0, old[(x,y)] - conf.decr_amt) } } } } fn gather_neighbors(img: &Image, (x, y): (usize, usize), n: usize) -> f32 { let mut amt = 0.0; let mut tot = 0.0; let ns = n as isize; for i in -ns..ns { for j in -ns..ns { let xn = (i + x as isize) as usize; let yn = (j + y as isize) as usize; if xn > 0 && xn < img.dim() && yn > 0 && yn < img.dim() { amt += img[(xn,yn)]; tot += 1.0; } } } amt / tot } fn main() { for isize in 2..10 { for osize in (isize+2)..12 { let conf = Config { inner_size: isize*2, outer_size: osize*2, incr_amt: 0.05, decr_amt: 0.05, steps: 100, img_size: 256, }; let filename = format!("output/morph-m-{}-{}.pbm", isize*2, osize*2); println!("Printing to {:?}", filename); let mut old = Image::new_rand(conf.img_size); let mut new = Image::new(conf.img_size); for _ in 0..conf.steps { run_step(&old, &mut new, &conf); std::mem::swap(&mut new, &mut old); } let mut f = match fs::File::create(filename) { Ok(f) => f, _ => panic!("Unable to open file"), }; new.print(f); } } }