From 7ef25034fd8d4d5da22e8d9402a4302c962e3edc Mon Sep 17 00:00:00 2001
From: Paul Brinkmeier <brinkmeier@meqo.de>
Date: Sat, 29 Nov 2025 14:56:53 +0100
Subject: [PATCH] Impl basic loop

---
 src/game.rs     | 149 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/geometry.rs |  94 +++++++++++++++++++++---------
 src/main.rs     |  50 ++++++++--------
 3 files changed, 243 insertions(+), 50 deletions(-)
 create mode 100644 src/game.rs

diff --git a/src/game.rs b/src/game.rs
new file mode 100644
index 0000000..0302dd4
--- /dev/null
+++ b/src/game.rs
@@ -0,0 +1,149 @@
+use crossterm::event::{Event, KeyCode};
+use ratatui::{
+    Frame, buffer::{Buffer, Cell}, layout::Rect, style::Color, widgets::{Block, Widget}
+};
+
+use crate::geometry::{Grid, P2, V2};
+
+pub struct GameModel {
+    player_pos: P2<isize>,
+    room: Room,
+}
+
+struct Room {
+    size: V2<usize>,
+}
+
+impl GameModel {
+    pub fn new() -> Self {
+        Self {
+            player_pos: P2::new(0, 0),
+            room: Room {
+                size: V2::new(20, 10),
+            },
+        }
+    }
+
+    pub fn update(self, event: Event) -> Option<Self> {
+        match event {
+            Event::Key(key_event) => match key_event.code {
+                KeyCode::Char('q') => return None,
+                KeyCode::Char('j') => {
+                    return Some(Self {
+                        player_pos: self.player_pos + V2::new(0, 1),
+                        ..self
+                    })
+                },
+                KeyCode::Char('k') => {
+                    return Some(Self {
+                        player_pos: self.player_pos + V2::new(0, -1),
+                        ..self
+                    })
+                },
+                KeyCode::Char('h') => {
+                    return Some(Self {
+                        player_pos: self.player_pos + V2::new(-1, 0),
+                        ..self
+                    })
+                },
+                KeyCode::Char('l') => {
+                    return Some(Self {
+                        player_pos: self.player_pos + V2::new(1, 0),
+                        ..self
+                    })
+                },
+                _ => (),
+            },
+            _ => (),
+        }
+
+        Some(self)
+    }
+
+    pub fn render(&self, frame: &mut Frame) {
+        let camera_block = Block::bordered().title("camera");
+        let camera_area = camera_block.inner(frame.area());
+        let camera = CameraWidget::new(self);
+
+        frame.render_widget(camera_block, frame.area());
+        frame.render_widget(camera, camera_area);
+    }
+
+    fn render_tiles(&self) -> Grid<Tile> {
+        let mut tiles = Grid::from_fn(self.room.size.x, self.room.size.y, |_x, _y| Tile::Floor);
+
+        tiles
+            .get_mut(P2::new(1, 1))
+            .map(|tile| *tile = Tile::Ladder);
+
+        tiles
+            .get_mut(P2::new(5, 2))
+            .map(|tile| *tile = Tile::Amphora);
+
+        tiles
+            .get_mut(P2::new(8, 5))
+            .map(|tile| *tile = Tile::Frog);
+
+        tiles
+            .get_mut(self.player_pos)
+            .map(|tile| *tile = Tile::Player);
+
+
+        tiles
+    }
+}
+
+enum Tile {
+    Floor,
+    Ladder,
+    Player,
+    Amphora,
+    Frog,
+}
+
+impl Tile {
+    fn render(&self, cell: &mut Cell) {
+        match self {
+            Tile::Floor => {
+                cell.set_symbol(" ");
+            }
+            Tile::Ladder => {
+                cell.set_symbol("Ħ");
+            }
+            Tile::Player => {
+                cell.set_symbol("▲̶͈̊");
+            }
+            Tile::Amphora => {
+                cell.set_symbol("⚱").set_fg(Color::LightRed);
+            }
+            Tile::Frog => {
+                cell.set_symbol("ä̃").set_fg(Color::Green);
+            }
+        }
+    }
+}
+
+struct CameraWidget<'a> {
+    model: &'a GameModel,
+}
+impl<'a> CameraWidget<'a> {
+    fn new(model: &'a GameModel) -> Self {
+        Self { model }
+    }
+}
+
+impl<'a> Widget for CameraWidget<'a> {
+    fn render(self, area: Rect, buf: &mut Buffer) {
+        let tiles = self.model.render_tiles();
+        for y in 0..area.height {
+            for x in 0..area.width {
+                let cell = &mut buf[(area.left() + x, area.top() + y)];
+                if let Some(tile) = tiles.get(P2::new(x as isize, y as isize)) {
+                    tile.render(cell);
+                } else {
+                    cell.set_symbol(".");
+                }
+            }
+        }
+    }
+}
diff --git a/src/geometry.rs b/src/geometry.rs
index 9f6fac5..c6b22a9 100644
--- a/src/geometry.rs
+++ b/src/geometry.rs
@@ -1,64 +1,106 @@
 use std::ops::{Add, Div, Sub};
 
 #[derive(Clone, Copy, Debug, PartialEq)]
-struct P2 {
-    x: i32,
-    y: i32,
+pub struct P2<T> {
+    x: T,
+    y: T,
 }
 
-impl P2 {
-    fn new(x: i32, y: i32) -> Self {
+impl<T> P2<T> {
+    pub fn new(x: T, y: T) -> Self {
         Self { x, y }
     }
 }
-impl Add<V2> for P2 {
-    type Output = P2;
 
-    fn add(self, rhs: V2) -> Self::Output {
+impl<T: Copy + Add<T>> Add<V2<T>> for P2<T> {
+    type Output = P2<<T as Add>::Output>;
+
+    fn add(self, rhs: V2<T>) -> Self::Output {
         P2::new(self.x + rhs.x, self.y + rhs.y)
     }
 }
 
-impl Sub<P2> for P2 {
-    type Output = V2;
+impl<T: Copy + Sub<T>> Sub<P2<T>> for P2<T> {
+    type Output = V2<<T as Sub>::Output>;
 
-    fn sub(self, rhs: P2) -> Self::Output {
+    fn sub(self, rhs: P2<T>) -> Self::Output {
         V2::new(self.x - rhs.x, self.y - rhs.y)
     }
 }
 
-impl Sub<V2> for P2 {
-    type Output = P2;
+impl<T: Copy + Sub<T>> Sub<V2<T>> for P2<T> {
+    type Output = P2<<T as Sub>::Output>;
 
-    fn sub(self, rhs: V2) -> Self::Output {
+    fn sub(self, rhs: V2<T>) -> Self::Output {
         P2::new(self.x - rhs.x, self.y - rhs.y)
     }
 }
 
-impl Div<i32> for P2 {
-    type Output = P2;
+impl<T: Copy + Div<T>> Div<T> for P2<T> {
+    type Output = P2<<T as Div>::Output>;
 
-    fn div(self, rhs: i32) -> Self::Output {
-        Self::new(self.x / rhs, self.y / rhs)
+    fn div(self, rhs: T) -> Self::Output {
+        P2::new(self.x / rhs, self.y / rhs)
     }
 }
 
 #[derive(Debug)]
-struct V2 {
-    x: i32,
-    y: i32,
+pub struct V2<T> {
+    pub x: T,
+    pub y: T,
 }
 
-impl V2 {
-    fn new(x: i32, y: i32) -> Self {
+impl<T> V2<T> {
+    pub fn new(x: T, y: T) -> Self {
         Self { x, y }
     }
 }
 
-impl Div<i32> for V2 {
-    type Output = V2;
+impl<T: Copy + Div<T>> Div<T> for V2<T> {
+    type Output = V2<<T as Div>::Output>;
 
-    fn div(self, rhs: i32) -> Self::Output {
+    fn div(self, rhs: T) -> Self::Output {
         V2::new(self.x / rhs, self.y / rhs)
     }
 }
+
+pub struct Grid<T> {
+    dims: V2<usize>,
+    elements: Vec<T>,
+}
+
+impl<T> Grid<T> {
+    pub fn from_fn(width: usize, height: usize, mut f: impl FnMut(usize, usize) -> T) -> Self {
+        let mut elements = Vec::new();
+        for y in 0..height {
+            for x in 0..width {
+                elements.push(f(x, y));
+            }
+        }
+        Self {
+            dims: V2::new(width, height),
+            elements,
+        }
+    }
+
+    pub fn get(&self, index: P2<isize>) -> Option<&T> {
+        self.valid_index(index).map(|index| &self.elements[index])
+    }
+
+    pub fn get_mut(&mut self, index: P2<isize>) -> Option<&mut T> {
+        self.valid_index(index)
+            .map(|index| &mut self.elements[index])
+    }
+
+    fn valid_index(&self, index: P2<isize>) -> Option<usize> {
+        if index.x >= 0
+            && (index.x as usize) < self.dims.x
+            && index.y >= 0
+            && (index.y as usize) < self.dims.y
+        {
+            Some((index.y as usize) * self.dims.x + (index.x as usize))
+        } else {
+            None
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index f457bdc..aa64287 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,29 +1,31 @@
-use std::cmp::max;
-
+mod game;
 mod geometry;
-mod noise;
-mod terrain;
 
-use noise::Noise;
+use color_eyre::eyre::Result;
+use crossterm::event;
+use ratatui::DefaultTerminal;
 
-fn main() {
-    let width = 50;
-    let height = 20;
+use game::GameModel;
 
-    let long_side = max(width, height) as f32;
-
-    let mut rand = rand::rng();
-    let height_noise = Noise::from_freqs(&mut rand, 12, 16, 3);
-    let tree_cover_noise = Noise::from_freqs(&mut rand, 12, 16, 4);
-
-    for y in 0..height {
-        for x in 0..width {
-            let h = height_noise.sample(x as f32 / long_side, y as f32 / long_side);
-            let t = tree_cover_noise.sample(x as f32 / long_side, y as f32 / long_side);
-
-            let terrain = terrain::terrain(h, t);
-            print!("{}", terrain.printable());
-        }
-        println!();
-    }
+fn main() -> Result<()> {
+            
+    let mut terminal = ratatui::init();
+    let result = main_loop(&mut terminal);
+    ratatui::restore();
+    result
 }
+
+fn main_loop(terminal: &mut DefaultTerminal) -> Result<()> {
+    let mut model = GameModel::new();
+    loop {
+        terminal.draw(|frame| {
+            model.render(frame)
+        })?;
+
+        let term_event = event::read()?;
+        match model.update(term_event) {
+            Some(new_model) => model = new_model,
+            None => break Ok(()),
+        }
+    }
+}
\ No newline at end of file