From 7e23dc9d9c9fa9f9f654b89a9573b6e08b76ad9e Mon Sep 17 00:00:00 2001
From: Franz Dietrich <dietrich@teilgedanken.de>
Date: Fri, 17 Oct 2025 19:17:22 +0200
Subject: [PATCH] add two threading examples

---
 turtle-lib/examples/game_logic_demo.rs  | 106 +++++++
 turtle-lib/examples/hangman_threaded.rs | 370 ++++++++++++++++++++++++
 2 files changed, 476 insertions(+)
 create mode 100644 turtle-lib/examples/game_logic_demo.rs
 create mode 100644 turtle-lib/examples/hangman_threaded.rs

diff --git a/turtle-lib/examples/game_logic_demo.rs b/turtle-lib/examples/game_logic_demo.rs
new file mode 100644
index 0000000..7cf71b0
--- /dev/null
+++ b/turtle-lib/examples/game_logic_demo.rs
@@ -0,0 +1,106 @@
+//! Example: Game Logic in Separate Thread
+//!
+//! This example demonstrates how to run game logic in a separate thread
+//! while keeping the render loop responsive on the main thread.
+//!
+//! The main thread handles rendering and animation, while game logic
+//! threads can perform blocking operations (like fetching data) and
+//! send turtle commands via channels.
+
+use std::thread;
+use std::time::Duration;
+use turtle_lib::*;
+
+#[macroquad::main("Game Logic Threading")]
+async fn main() {
+    let mut app = TurtleApp::new();
+
+    // Create two turtles and get their command senders
+    let turtle1_tx = app.create_turtle_channel(100);
+    let turtle2_tx = app.create_turtle_channel(100);
+
+    // Spawn first game logic thread
+    let _thread1 = thread::spawn({
+        let tx = turtle1_tx.clone();
+        move || {
+            // Simulate some blocking work (e.g., network request, calculation)
+            println!("Thread 1: Starting work...");
+            thread::sleep(Duration::from_millis(500));
+
+            // Now send turtle commands
+            let mut plan = create_turtle_plan();
+            plan.set_pen_color(BLUE)
+                .forward(100.0)
+                .right(90.0)
+                .forward(100.0)
+                .right(90.0)
+                .forward(100.0)
+                .right(90.0)
+                .forward(100.0);
+
+            tx.send(plan.build())
+                .expect("Failed to send commands for turtle 1");
+            println!("Thread 1: Commands sent!");
+
+            // Send more commands in a loop
+            for i in 0..10 {
+                thread::sleep(Duration::from_millis(300));
+                let mut step = create_turtle_plan();
+                step.right(36.0).forward(50.0);
+                let _ = tx.try_send(step.build());
+                println!("Thread 1: Step {} sent", i + 1);
+            }
+        }
+    });
+
+    // Spawn second game logic thread
+    let _thread2 = thread::spawn({
+        let tx = turtle2_tx.clone();
+        move || {
+            // Different timing than thread1
+            println!("Thread 2: Starting work...");
+            thread::sleep(Duration::from_millis(1000));
+
+            // Draw a circle with turtle2
+            let mut plan = create_turtle_plan();
+            plan.set_pen_color(RED).circle_left(75.0, 360.0, 72);
+
+            tx.send(plan.build())
+                .expect("Failed to send commands for turtle 2");
+            println!("Thread 2: Circle sent!");
+        }
+    });
+
+    // Main render loop
+    let mut frame_count = 0;
+    loop {
+        // Check for quit
+        if macroquad::prelude::is_key_pressed(macroquad::prelude::KeyCode::Escape)
+            || macroquad::prelude::is_key_pressed(macroquad::prelude::KeyCode::Q)
+        {
+            break;
+        }
+
+        // Clear background
+        macroquad::prelude::clear_background(WHITE);
+
+        // Process incoming commands from game logic threads
+        // This drains all pending commands from turtle channels
+        app.process_commands();
+
+        // Update animation state (tweening, etc.)
+        app.update();
+
+        // Render the turtles
+        app.render();
+
+        frame_count += 1;
+        if frame_count % 60 == 0 {
+            println!("Rendered {} frames", frame_count);
+        }
+
+        macroquad::prelude::next_frame().await;
+    }
+
+    println!("Finished!");
+}
diff --git a/turtle-lib/examples/hangman_threaded.rs b/turtle-lib/examples/hangman_threaded.rs
new file mode 100644
index 0000000..374825d
--- /dev/null
+++ b/turtle-lib/examples/hangman_threaded.rs
@@ -0,0 +1,370 @@
+//! Hangman Game with Threading
+//!
+//! A classic hangman game where game logic runs in a separate thread
+//! while the render loop stays responsive. The user can make guesses
+//! while turtle animations play smoothly.
+//!
+//! Run with: `cargo run --package turtle-lib --example hangman_threaded`
+
+use std::io::{self, Write};
+use std::sync::mpsc;
+use std::thread;
+use turtle_lib::*;
+
+// Word list for the game
+const WORDS: &[&str] = &[
+    "turtle",
+    "graphics",
+    "threading",
+    "rust",
+    "animation",
+    "crossbeam",
+    "channel",
+    "synchronization",
+    "parallel",
+    "concurrent",
+];
+
+#[macroquad::main("Hangman")]
+async fn main() {
+    let mut app = TurtleApp::new();
+
+    // Create three turtles: hangman, lines, and smiley
+    let hangman_tx = app.create_turtle_channel(100);
+    let lines_tx = app.create_turtle_channel(100);
+    let smiley_tx = app.create_turtle_channel(100);
+
+    // Channel for game logic to communicate with render thread
+    let (tx, rx) = mpsc::channel();
+
+    // Spawn game logic thread
+    let game_thread = thread::spawn({
+        let hangman = hangman_tx.clone();
+        let lines = lines_tx.clone();
+        let smiley = smiley_tx.clone();
+        let tx = tx.clone();
+
+        move || {
+            run_game_logic(hangman, lines, smiley, tx);
+        }
+    });
+
+    // Main render loop
+    let mut frame = 0;
+    loop {
+        // Check for quit
+        if macroquad::prelude::is_key_pressed(macroquad::prelude::KeyCode::Escape)
+            || macroquad::prelude::is_key_pressed(macroquad::prelude::KeyCode::Q)
+        {
+            break;
+        }
+
+        // Process incoming commands from game thread
+        while let Ok(msg) = rx.try_recv() {
+            match msg {
+                GameMessage::GameOver { won, word } => {
+                    if won {
+                        println!("🎉 You Won! The word was: {}", word);
+                    } else {
+                        println!("💀 You Lost! The word was: {}", word);
+                    }
+                    break;
+                }
+            }
+        }
+
+        // Clear and render
+        macroquad::prelude::clear_background(WHITE);
+        app.process_commands();
+        app.update();
+        app.render();
+
+        frame += 1;
+        if frame % 60 == 0 {
+            println!("Rendered {} frames", frame / 60);
+        }
+
+        macroquad::prelude::next_frame().await;
+    }
+
+    // Wait for game thread to finish
+    game_thread.join().ok();
+    println!("Game ended. Goodbye!");
+}
+
+enum GameMessage {
+    GameOver { won: bool, word: String },
+}
+
+fn run_game_logic(
+    hangman_tx: TurtleCommandSender,
+    lines_tx: TurtleCommandSender,
+    smiley_tx: TurtleCommandSender,
+    tx: mpsc::Sender<GameMessage>,
+) {
+    let secret = choose_word();
+    println!("Starting hangman game...");
+    println!("Secret word has {} letters", secret.len());
+
+    // Setup: Position hangman turtle and draw base (hill + mast)
+    {
+        let mut plan = create_turtle_plan();
+        setup_hangman(&mut plan);
+        draw_hill(&mut plan);
+        hangman_tx.send(plan.build()).ok();
+    }
+
+    // Give render thread time to process
+    std::thread::sleep(std::time::Duration::from_millis(100));
+
+    let mut all_guesses = String::new();
+    let mut wrong_guesses = 0;
+    const MAX_WRONG: usize = 8; // 8 body parts after base
+
+    // Main game loop
+    loop {
+        // Draw current state of lines
+        draw_lines_state(&lines_tx, &secret, &all_guesses);
+
+        // Check if won
+        if secret.chars().all(|c| all_guesses.contains(c)) {
+            draw_smiley(&smiley_tx, true);
+            tx.send(GameMessage::GameOver {
+                won: true,
+                word: secret.to_string(),
+            })
+            .ok();
+            break;
+        }
+
+        // Check if lost
+        if wrong_guesses >= MAX_WRONG {
+            draw_smiley(&smiley_tx, false);
+            tx.send(GameMessage::GameOver {
+                won: false,
+                word: secret.to_string(),
+            })
+            .ok();
+            break;
+        }
+
+        // Ask for guess
+        let guess = ask_for_letter();
+        let guess_lower = guess.to_lowercase();
+
+        // Check if already guessed
+        if all_guesses.contains(&guess_lower) {
+            println!("You already guessed '{}'", guess_lower);
+            continue;
+        }
+
+        all_guesses.push_str(&guess_lower);
+
+        if secret.contains(&guess_lower) {
+            println!("✓ Correct! '{}' is in the word", guess_lower);
+        } else {
+            println!("✗ Wrong! '{}' is NOT in the word", guess_lower);
+            wrong_guesses += 1;
+
+            // Draw next hangman step
+            draw_hangman_step(&hangman_tx, wrong_guesses);
+            println!("Wrong guesses: {}/{}", wrong_guesses, MAX_WRONG);
+        }
+    }
+}
+
+fn choose_word() -> &'static str {
+    WORDS[(std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs() as usize)
+        % WORDS.len()]
+}
+
+fn ask_for_letter() -> String {
+    print!("Guess a letter: ");
+    io::stdout().flush().ok();
+
+    let mut guess = String::new();
+    io::stdin().read_line(&mut guess).ok();
+    guess.trim().to_string()
+}
+
+fn setup_hangman(plan: &mut TurtlePlan) {
+    plan.hide()
+        .set_speed(1001) // Instant mode
+        .set_pen_width(3.0) // Thicker lines for visibility
+        .set_pen_color(BLACK)
+        .pen_up()
+        .go_to(vec2(-100.0, -100.0)) // More centered position
+        .pen_down();
+}
+
+fn draw_hangman_step(tx: &TurtleCommandSender, step: usize) {
+    let mut plan = create_turtle_plan();
+    plan.set_speed(1001); // Instant mode
+
+    match step {
+        1 => draw_mast(&mut plan),
+        2 => draw_bar(&mut plan),
+        3 => draw_support(&mut plan),
+        4 => draw_rope(&mut plan),
+        5 => draw_head(&mut plan),
+        6 => draw_arms(&mut plan),
+        7 => draw_body(&mut plan),
+        8 => draw_legs(&mut plan),
+        _ => {}
+    }
+
+    tx.send(plan.build()).ok();
+}
+
+// Hangman drawing functions (scaled down for visibility)
+fn draw_hill(plan: &mut TurtlePlan) {
+    plan.circle_left(50.0, 180.0, 36)
+        .left(180.0)
+        .circle_right(50.0, 90.0, 36)
+        .right(90.0);
+}
+
+fn draw_mast(plan: &mut TurtlePlan) {
+    plan.forward(150.0);
+}
+
+fn draw_bar(plan: &mut TurtlePlan) {
+    plan.right(90.0).forward(75.0);
+}
+
+fn draw_support(plan: &mut TurtlePlan) {
+    plan.backward(50.0)
+        .right(135.0)
+        .forward(35.355)
+        .backward(35.355)
+        .left(135.0)
+        .forward(50.0);
+}
+
+fn draw_rope(plan: &mut TurtlePlan) {
+    plan.set_pen_width(2.0).right(90.0).forward(35.0);
+}
+
+fn draw_head(plan: &mut TurtlePlan) {
+    plan.left(90.0).circle_right(15.0, 540.0, 72);
+}
+
+fn draw_arms(plan: &mut TurtlePlan) {
+    plan.left(60.0)
+        .forward(50.0)
+        .backward(50.0)
+        .left(60.0)
+        .forward(50.0)
+        .backward(50.0)
+        .right(30.0);
+}
+
+fn draw_body(plan: &mut TurtlePlan) {
+    plan.forward(50.0);
+}
+
+fn draw_legs(plan: &mut TurtlePlan) {
+    plan.right(20.0)
+        .forward(60.0)
+        .backward(60.0)
+        .left(40.0)
+        .forward(60.0)
+        .backward(60.0)
+        .right(20.0);
+}
+
+fn draw_lines_state(tx: &TurtleCommandSender, secret: &str, all_guesses: &str) {
+    let mut plan = create_turtle_plan();
+    plan.hide()
+        .set_speed(1001) // Instant mode
+        .set_pen_color(BLACK)
+        .set_pen_width(2.0)
+        .pen_up()
+        .go_to(vec2(-100.0, 100.0)) // Top of screen
+        .pen_down()
+        .right(90.0);
+
+    // Print word state in console
+    print!("Word: ");
+    for letter in secret.chars() {
+        if all_guesses.contains(letter) {
+            print!("{} ", letter);
+            plan.forward(20.0);
+        } else {
+            print!("_ ");
+            plan.forward(20.0);
+        }
+    }
+    println!();
+
+    // Draw underscores/circles for each letter
+    for letter in secret.chars() {
+        if all_guesses.contains(letter) {
+            // Draw green circle for revealed letter
+            plan.pen_up()
+                .forward(2.5)
+                .right(90.0)
+                .set_pen_color(GREEN)
+                .pen_down()
+                .circle_left(7.5, 360.0, 24)
+                .set_pen_color(BLACK)
+                .left(90.0)
+                .backward(2.5)
+                .pen_up();
+        } else {
+            // Draw black underscore
+            plan.forward(5.0);
+        }
+        plan.forward(15.0).pen_down();
+    }
+
+    tx.send(plan.build()).ok();
+}
+
+fn draw_smiley(tx: &TurtleCommandSender, won: bool) {
+    let mut plan = create_turtle_plan();
+    plan.hide()
+        .set_speed(1001) // Instant mode
+        .pen_up()
+        .go_to(vec2(100.0, 0.0)) // Right side of screen
+        .pen_down()
+        .set_pen_color(if won { GREEN } else { RED });
+
+    // Face
+    plan.circle_left(50.0, 360.0, 72);
+
+    // Left eye
+    plan.pen_up()
+        .forward(27.5)
+        .right(90.0)
+        .forward(20.0)
+        .pen_down()
+        .circle_left(3.0, 360.0, 24);
+
+    // Right eye
+    plan.pen_up()
+        .forward(42.5)
+        .pen_down()
+        .circle_left(3.0, 360.0, 24);
+
+    // Mouth
+    plan.pen_up()
+        .backward(42.5)
+        .left(90.0)
+        .backward(40.0)
+        .right(90.0)
+        .pen_down();
+
+    if won {
+        // Smile
+        plan.right(45.0).circle_left(32.5, 90.0, 36);
+    } else {
+        // Frown
+        plan.left(45.0).circle_right(32.5, 90.0, 36);
+    }
+
+    tx.send(plan.build()).ok();
+}