From b37fb0bfd9272484c5fa93e2826ee3433eeedda6 Mon Sep 17 00:00:00 2001
From: CrispyPin <crispin@tasa.se>
Date: Sat, 22 Jul 2023 17:04:10 +0200
Subject: [PATCH] rle parsing

---
 .gitignore    |  1 +
 src/lib.rs    |  1 +
 src/main.rs   | 18 ++++++++++-----
 src/region.rs | 31 +++++++++++++++++++++++++-
 src/rle.rs    | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/tile.rs   |  4 ++--
 6 files changed, 109 insertions(+), 8 deletions(-)
 create mode 100644 src/rle.rs

diff --git a/.gitignore b/.gitignore
index ea8c4bf..6631e2e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /target
+*.rle
diff --git a/src/lib.rs b/src/lib.rs
index dae266f..106cec6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,3 @@
 pub mod region;
+pub mod rle;
 pub mod tile;
diff --git a/src/main.rs b/src/main.rs
index 664dad8..a71f106 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,13 +1,21 @@
-use gol_bitwise::region::Region;
+use std::env;
+
+use gol_bitwise::{region::Region, rle};
 
 fn main() {
-	let mut region = Region::new(1, 1);
-	region.randomise();
-	print!("\x1B[2J"); // clear screen
+	let mut region = if let Some(file) = env::args().nth(1) {
+		Region::from_bools(rle::parse(&file).unwrap())
+	} else {
+		let mut r = Region::new(1, 1);
+		r.randomise();
+		r
+	};
+	region.auto_grow();
 
 	loop {
+		print!("\x1B[2J"); // clear screen
 		print!("\x1B[u"); // reset cursor
-		region.print_all(true);
+		region.print_all(false);
 		region.step();
 		region.auto_grow();
 		{
diff --git a/src/region.rs b/src/region.rs
index 619da53..48f3d5e 100644
--- a/src/region.rs
+++ b/src/region.rs
@@ -1,4 +1,4 @@
-use crate::tile::{Edges, Tile, WIDTH};
+use crate::tile::{Edges, Row, Tile, WIDTH};
 
 pub struct Region {
 	/// rows of tiles
@@ -11,6 +11,35 @@ impl Region {
 		Self { tiles }
 	}
 
+	pub fn from_bools(board: Vec<Vec<bool>>) -> Self {
+		let height = board.len() / WIDTH + 1;
+		let width = board[0].len() / WIDTH + 1;
+		let mut tiles = vec![vec![Tile::new(); width]; height];
+
+		for tile_y in 0..height {
+			for tile_x in 0..width {
+				let tile = &mut tiles[tile_y][tile_x];
+				for y in 0..WIDTH {
+					let by = tile_y * WIDTH + y;
+					if by >= board.len() {
+						break;
+					}
+					let mut row = 0;
+					for x in 0..WIDTH {
+						let bx = tile_x * WIDTH + x;
+						if bx >= board[by].len() {
+							break;
+						}
+						row |= (board[by][bx] as Row) << (WIDTH - x - 1) as Row;
+					}
+					tile.rows[y] = row;
+				}
+			}
+		}
+
+		Self { tiles }
+	}
+
 	pub fn randomise(&mut self) {
 		for row in self.tiles.iter_mut() {
 			for tile in row {
diff --git a/src/rle.rs b/src/rle.rs
new file mode 100644
index 0000000..0f079ef
--- /dev/null
+++ b/src/rle.rs
@@ -0,0 +1,62 @@
+use std::fs;
+
+// one of the shittest RLE parsers in existence :)
+
+pub fn parse(filename: &str) -> Option<Vec<Vec<bool>>> {
+	let file = fs::read_to_string(filename).ok()?;
+	let mut meta = None;
+	let mut rle = String::new();
+	for line in file.lines() {
+		if line.starts_with('#') {
+			continue;
+		}
+		if meta.is_none() {
+			meta = Some(line.to_owned());
+			continue;
+		}
+		rle.push_str(line);
+	}
+	let meta = meta?;
+
+	let properties = meta.split(", ").collect::<Vec<_>>();
+	let width: usize = properties.get(0)?.split('=').nth(1)?.trim().parse().ok()?;
+	let height: usize = properties.get(1)?.split('=').nth(1)?.trim().parse().ok()?;
+
+	let mut board = vec![vec![false; width]; height];
+
+	let mut x = 0;
+	let mut y = 0;
+	let mut run_count = 0;
+
+	for char in rle.chars() {
+		match char {
+			'b' => {
+				run_count = run_count.max(1);
+				x += run_count;
+				run_count = 0;
+			}
+			'o' => {
+				run_count = run_count.max(1);
+				for rx in x..(x + run_count) {
+					board[y][rx] = true;
+				}
+				x += run_count;
+				run_count = 0;
+			}
+			'$' => {
+				run_count = run_count.max(1);
+				y += run_count;
+				run_count = 0;
+				x = 0;
+			}
+			'0'..='9' => {
+				run_count *= 10;
+				run_count += ((char as u8) - b'0') as usize;
+			}
+			'!' => break,
+			'\n' => (),
+			other => println!("Unknown token {other} in RLE"),
+		}
+	}
+	Some(board)
+}
diff --git a/src/tile.rs b/src/tile.rs
index 3f5ad5b..778029f 100644
--- a/src/tile.rs
+++ b/src/tile.rs
@@ -1,4 +1,4 @@
-type Row = u16;
+pub type Row = u16;
 
 pub const WIDTH: usize = Row::BITS as usize;
 const LAST: usize = WIDTH - 1;
@@ -15,7 +15,7 @@ pub struct Edges {
 	se: bool,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Tile {
 	pub rows: [Row; WIDTH],
 }