From 4f8f02e146b2880fc514912865361d8a7090c150 Mon Sep 17 00:00:00 2001
From: Rasmus Kaj <kaj@kth.se>
Date: Thu, 5 Oct 2023 20:54:59 +0200
Subject: [PATCH] Initial commit.

---
 .gitignore  |  2 ++
 Cargo.toml  |  8 ++++++
 src/main.rs | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.toml
 create mode 100644 src/main.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4fffb2f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/target
+/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..331c846
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "ttylia"
+version = "0.1.0"
+edition = "2021"
+authors = ["Rasmus Kaj <kaj@kth.se>"]
+
+[dependencies]
+num-complex = { version = "0.2", default-features = false }
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..1d23399
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,82 @@
+use num_complex::Complex32;
+use std::{io::{self, Write}, thread::sleep, time::{Duration, Instant}};
+
+const CHARS: &[u8; 33] = b"@. .,:;-~+*i=xom\\//11II77OO77MMMM";
+
+fn main() {
+    const WIDTH: u16 = 40;
+    const HEIGHT: u16 = 24;
+    const SY: f32 = 3.2 / (HEIGHT as f32);
+    const SX: f32 = SY / 1.4;
+    const X0: f32 = ((WIDTH / 2) as f32) * SX;
+    const Y0: f32 = ((HEIGHT / 2) as f32) * SY;
+    let frame_time = Duration::from_millis(300 /*1000/30*/);
+    let max_iter = u8::try_from(CHARS.len()-1).unwrap();
+    let mut buffer = [0u8; (WIDTH * HEIGHT) as usize];
+    let mut c = Complex32 { re: -0.5, im: 0.5 };
+    let mut rotor = Complex32 { re: 1., im: frame_time.as_secs_f32() * 0.2 };
+    let mut frame = 0;
+    let mut out  = io::stdout().lock();
+    out.write_all(b"\x1B[2J").unwrap();
+    loop {
+        let frame_start = Instant::now();
+        c *= rotor;
+        if c.norm_sqr() > 2. {
+            rotor *= (1. / rotor.norm_sqr()).sqrt();
+        }
+        frame += 1;
+        let mut p = 0;
+        for y in 0..HEIGHT / 2 {
+            let zy = f32::from(y) * SY - Y0;
+            for x in 0..WIDTH {
+                let z = Complex32 {
+                    re: f32::from(x) * SX - X0,
+                    im: zy,
+                };
+                let val = pixel(julia(z, c, max_iter));
+                buffer[p] = val;
+                p += 1;
+                buffer[buffer.len() - p] = val;
+            }
+        }
+        let status = format!("ttylia | Rasmus Kaj | Rust | {:.3}", c.l1_norm());
+        buffer[0..status.len()].clone_from_slice(status.as_bytes());
+        //buffer[0] = b't';
+        out.write_all(b"\x1B[H").unwrap();
+        for y in 0..HEIGHT {
+            out.write_all(b"\x1B#6").unwrap();
+            out.write_all(&buffer[usize::from(y * WIDTH)..usize::from((y + 1) * WIDTH)]).unwrap();
+        }
+        out.write_all(b"\x1B#6").unwrap();
+        //out.write_all(b"\r").unwrap();
+        //out.write_all(b"\x1B[Httylia | Rasmus Kaj | Rust \n").unwrap();
+        //writeln!(out, "| {c:+.5} | {frame:4} ").unwrap();
+        out.flush().unwrap();
+        if let Some(remains) = frame_time.checked_sub(frame_start.elapsed()) {
+            //writeln!(out, " {remains:.3?} ").unwrap();
+            sleep(remains);
+        //} else {
+        //    writeln!(out, "Hurry!").unwrap();
+        }
+    }
+}
+
+fn pixel(i: u8) -> u8 {
+    CHARS[usize::from(i)]
+    // u32::from_be_bytes([0xff, i * 6, i + i / 2, i.saturating_mul(8)])
+}
+
+fn julia(z: Complex32, c: Complex32, max_i: u8) -> u8 {
+    let mut z = z;
+    for i in 1..max_i {
+        if z.norm_sqr() > 4.0 {
+            return i;
+        }
+        z = z * z + c;
+    }
+    if z.norm_sqr() > 4.0 {
+        max_i
+    } else {
+        0
+    }
+}