Add mutation for layouts.

src/layout/mod.rs

@@ -1,6 +1,6 @@
 use crate::common::visualize::{Color, Symbol, Visualization, Visualize};
 use crate::prelude::*;
-use rand::Rng;
+use rand::{seq::SliceRandom, Rng};
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -143,11 +143,115 @@ impl Layout<'_> {
 
     /// Mutate existing layout, creating a valid layout
     pub fn mutate<R: Rng + ?Sized>(&self, rng: &mut R) -> Self {
-        let s = self.clone();
+        let mut s = self.clone();
+
+        #[allow(clippy::type_complexity)]
+        let r: &[(&dyn Fn(&mut Layout, &mut R) -> bool, _)] = &[
+            (&Self::mutate_replace::<R>, 30),
+            (&Self::mutate_flip::<R>, 50),
+            (&Self::mutate_jiggle::<R>, 80),
+        ];
+
+        loop {
+            let p = r.choose_weighted(rng, |i| i.1).unwrap();
+
+            if p.0(&mut s, rng) && rng.gen_bool(0.4) {
+                break;
+            }
+        }
 
         s
     }
 
+    fn mutate_replace<R: Rng + ?Sized>(layout: &mut Layout, rng: &mut R) -> bool {
+        let i = rng.gen_range(0..layout.blocks.len());
+
+        let dir = rng.gen::<Direction>();
+
+        let b = &layout.problem.blocks[i];
+
+        let pos = match dir {
+            Direction::Up => Position::new(
+                rng.gen_range(0..=(layout.problem.size.x - b.size.x)),
+                rng.gen_range(0..=(layout.problem.size.y - b.size.y)),
+            ),
+            Direction::Right => Position::new(
+                rng.gen_range((b.size.y - 1)..layout.problem.size.x),
+                rng.gen_range(0..=(layout.problem.size.y - b.size.x)),
+            ),
+            Direction::Down => Position::new(
+                rng.gen_range((b.size.x - 1)..layout.problem.size.x),
+                rng.gen_range((b.size.y - 1)..layout.problem.size.y),
+            ),
+            Direction::Left => Position::new(
+                rng.gen_range(0..=(layout.problem.size.x - b.size.y)),
+                rng.gen_range((b.size.x - 1)..layout.problem.size.y),
+            ),
+        };
+
+        if layout.blocks.iter().enumerate().all(|(j, (p, d))| {
+            j == i || !Self::collision((&layout.problem.blocks[j], *p, *d), (b, pos, dir))
+        }) {
+            layout.blocks[i] = (pos, dir);
+            true
+        } else {
+            false
+        }
+    }
+
+    fn mutate_flip<R: Rng + ?Sized>(layout: &mut Layout, rng: &mut R) -> bool {
+        let i = rng.gen_range(0..layout.blocks.len());
+        let b = &mut layout.blocks[i];
+        let block = &layout.problem.blocks[i];
+
+        b.0 = match &b.1 {
+            Direction::Up => b.0 + block.size - Position::new(1, 1),
+            Direction::Right => b.0 + Position::new(1 - block.size.y, block.size.x - 1),
+            Direction::Down => b.0 - block.size + Position::new(1, 1),
+            Direction::Left => b.0 + Position::new(block.size.y - 1, 1 - block.size.x),
+        };
+        b.1 = b.1.reverse();
+
+        true
+    }
+
+    fn mutate_jiggle<R: Rng + ?Sized>(layout: &mut Layout, rng: &mut R) -> bool {
+        let i = rng.gen_range(0..layout.blocks.len());
+        let dir = rng.gen::<Direction>();
+        // let step = [(1, 10), (2, 5), (3, 5)]
+        //     .choose_weighted(rng, |i| i.1)
+        //     .unwrap()
+        //     .0;
+        let step = 1;
+
+        let b = &layout.problem.blocks[i];
+
+        let new_pos = layout.blocks[i].0.in_direction(&dir, step);
+
+        let (npos, nsize) = Self::normalize_pos((b, new_pos, layout.blocks[i].1));
+
+        if npos.x < 0
+            || npos.y < 0
+            || npos.x + nsize.x > layout.problem.size.x
+            || npos.y + nsize.y > layout.problem.size.y
+        {
+            return false;
+        }
+
+        if layout.blocks.iter().enumerate().all(|(j, (p, d))| {
+            j == i
+                || !Self::collision(
+                    (&layout.problem.blocks[j], *p, *d),
+                    (b, new_pos, layout.blocks[i].1),
+                )
+        }) {
+            layout.blocks[i].0 = new_pos;
+            true
+        } else {
+            false
+        }
+    }
+
     fn collision(
         block1: (&Block, Position, Direction),
         block2: (&Block, Position, Direction),