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+# Deimos in a Game of Tiles
+
+```deimos
+pub int TileGameMod
+  mut fn init(s: mut TileGameState) -> Void
+  mut fn tick(s: mut TileGameState) -> Void
+end
+
+pub extern class TileGameState
+  pub extern fn tiles() -> List<Tile>
+  
+  pub extern mut fn tilesMut() -> mut List<Title>
+  
+  pub extern fn player() -> Player
+end
+
+pub int Tile
+  fn x() -> Size
+  fn y() -> Size
+  fn walkingSpeed() -> Speed
+  fn runningSpeed() -> Speed
+  fn draw(s: TileGameState) -> TileDraw
+end
+
+pub record Color(red: Float, green: Float, blue: Float) end
+
+pub val-class Brightness
+  brightness: Double
+
+  pub ctor(brightness: Double)
+    if brightness >= 0 && brightness <= 1 then
+      self.brightness = brightness
+    else
+      throw IllegalArgumentException("Cannot have a brightness outside of 0.0-1.0 range; given ${brightness}")
+    end
+  end
+end
+
+pub record TileDraw(color: Color, brightness: Brightness) end
+
+pub record Speed(speed: Double) end
+
+pub extern class Player
+  pub extern fn isRunning() -> Boolean
+end
+
+pub class GrassTile(x: Size, y: Size) : Tile
+  pub enum Season
+    Green, Brown
+  end
+  
+  mut season: Season
+  
+  pub mut fn flipSeason() -> Void
+    match self.season
+      Season::Green => self.season = Season::Brown,
+      Season::Brown => self.season = Season::Green
+    end
+  end
+
+  pub fn x() -> Size = self.size
+  
+  pub fn y() -> Size = self.size
+
+  pub fn walkingSpeed() -> Speed = Speed(2.5)
+  
+  pub fn runningSpeed() -> Speed = Speed(4.0)
+  
+  fn getColor() -> Color
+    if self.season == Season::Green
+      Color(0.0F, 1.0F, 0.0F)
+    else
+      Color(0.6F, 0.3F, 0.0F)
+    end
+  end
+  
+  pub fn draw(s: TileGameState) -> TileDraw
+    let color = self.getColor()
+    if s.player().isRunning() then
+      TileDraw(color, Brightness(0.9))
+    else
+      TileDraw(color, Brightness(0.7))
+    end
+  end
+end
+
+pub class CoreMod : TileGameMod
+  mut tickCount = 0
+
+  pub mut fn init(s: mut TileGameState) -> Void
+    for x in 0..10 do
+      for y in 0..10 do
+        s.tilesMut() << GrassTile(x, y) 
+      end
+    end
+  end
+  
+  pub mut fn tick(s: mut TileGameState) -> Void
+    self.tickCount++
+    if tickCount == 16 * 10 then
+      self.tickCount = 0
+      let randomX = std::num::randomSize(0, 10)
+      let randomY = std::num::randomSize(0, 10)
+      let tileNumber = randomX * 10 + randomY
+      let tile = s.tilesMut().getMut(tileNumber)
+      if tile is GrassTile then
+        tile.flipSeason()
+      end
+    end
+  end
+end
+```
+
+```rust
+struct TileGameState {
+    tiles: Gc<Object>,
+    player: Gc<Player>
+}
+
+struct Player {
+    running: bool,
+    x: f64,
+    y: f64
+}
+
+struct Color {
+    r: f32,
+    g: f32,
+    b: f32
+}
+
+struct Brightness(f64);
+
+fn main() {
+    let mut dvm_context = load_context_with_mods();
+    let mut dvm_state = DvmState::new();
+
+    dvm_context.add_platform_function("TileGameState::tiles", |args: &[Value]| {
+        let this: Gc<TileGameState> = args[0].unwrap_native_object().downcast::<TileGameState>();
+        Value::Object(this.tiles)
+    });
+
+    dvm_context.add_platform_function("TileGameState::player", |args: &[Value]| {
+        let this: Gc<TileGameState> = args[0].unwrap_native_object().downcast::<TileGameState>();
+        Value::Object(this.player)
+    });
+
+    dvm_context.add_platform_function("Player::isRunning", |args: &[Value]| {
+        let this: Gc<Player> = args[0].unwrap_native_object().downcast::<Player>();
+        if this.running && is_in_bounds(this) {
+            Value::Boolean(true)
+        } else {
+            Value::Boolean(false)
+        }
+    });
+
+    let core_mod: Gc<Object> = construct_object(&mut dvm_state, &dvm_context, "CoreMod");
+    let tile_game_state: GcAny = construct_native_object(&mut dvm_state, &dvm_context, "TileGameState", TileGameState {
+        tiles: construct_object(&mut dvm_state, &dvm_context, "std::collections::List"),
+        player: construct_native_object(&mut dvm_state, &dvm_context, "Player", Player {
+            running: false,
+        }).downcast::<Player>()
+    });
+
+    call(&mut dvm_state, &dvm_context, "TileGameMod::init", &[
+        Value::Object(core_mod),
+        Value::NativeObject(tile_game_state),
+    ]);
+
+    loop {
+        if tick() {
+            call(&mut dvm_state, &dvm_context, "TileGameMod::tick", &[
+                Value::Object(core_mod),
+                Value::NativeObject(tile_game_state)
+            ]);
+        }
+        if frame() {
+            let tile_game_state: TileGameState = tile_game_state.downcast::<TileGameState>();
+            let tiles: Array<Gc<Object>> = call(
+                &mut dvm_state,
+                &dvm_context,
+                "std::collections::List::toArray",
+                &[Value::Object(tile_game_state)]
+            ).unwrap_array();
+
+            for tile in tiles {
+                let x: usize = call(&mut dvm_state, &dvm_context, "Tile::x", &[
+                    Value::Object(tile)
+                ]).unwrap_size();
+                let y: usize = call(&mut dvm_state, &dvm_context, "Tile::y", &[
+                    Value::Object(tile)
+                ]).unwrap_size();
+
+                let tile_draw: Gc<Object> = call(&mut dvm_state, &dvm_context, "Tile::draw", &[
+                    Value::Object(tile),
+                    Value::NativeObject(tile_game_state)
+                ]).unwrap_object();
+                let r: f32 = read_field_path(&tile_draw, "color.r").unwrap_float();
+                let g: f32 = read_field_path(&tile_draw, "color.g").unwrap_float();
+                let b: f32 = read_field_path(&tile_draw, "color.b").unwrap_float();
+                let color = Color {
+                    r,
+                    g,
+                    b
+                };
+                let brightness = Brightness(read_field_path(&tile_draw, "brightness.brightness").unwrap_double());
+                draw_tile(x, y, color, brightness);
+            }
+        }
+    }
+}
+```
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