feat: implement gameloop

Implement a basic game loop that draws the startscreen, and the map after you hit the right button

src/game.py

@@ -0,0 +1,151 @@
+"""Small playable demo that uses ``src.map.Map`` and the actor system.
+
+Controls:
+- WASD / arrow keys: move Knoll around the map
+- Space: switch between good/normal and bad/angry sprite
+- Esc / Q: quit
+
+The demo also places a few bad/angry actors as monsters in the rooms.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Optional
+
+import pygame
+
+from src.actors import Actor
+from src.map import Map, color_void, screen_h, screen_w, tile_size
+from src.settings import DEMO_ACTOR_HEIGHT, FPS, PLAYER_SPEED
+from src.startscreen import Startscreen
+
+
+# Keep the actor close to the map scale. The map tiles are 30x30, so 2 tiles
+# high makes the character readable without covering whole rooms/walls.
+
+
+def tile_center(column: int, row: int) -> tuple[int, int]:
+    """Return the pixel center of a map tile."""
+
+    return column * tile_size + tile_size // 2, row * tile_size + tile_size // 2
+
+
+class Game:
+    def __init__(self) -> None:
+        pygame.init()
+        self.screen = pygame.display.set_mode((screen_w, screen_h))
+        self.clock = pygame.time.Clock()
+        self.font = pygame.font.SysFont("monospace", 22, bold=True)
+        self.running = True
+
+        self.startscreen = Startscreen(self.screen)
+        self.state = "startscreen"
+        self.player_name: str = ""
+
+        self.map = Map()
+
+        # resolve the assets from the folder
+        assets_dir = Path(__file__).resolve().parent.parent / "assets"
+        actor_sides = Actor.load_sprite_sides(assets_dir, target_height=DEMO_ACTOR_HEIGHT)
+
+        if not actor_sides:
+            raise RuntimeError("No normal_*/angry_* actor sprite pairs found in assets/")
+
+        # Use the first pair for the player. With current assets this is Knoll.
+        self.player = Actor.from_sides(actor_sides[0], self.find_start_position())
+
+    def run(self, max_frames: Optional[int] = None) -> None:
+        """Run the demo. ``max_frames`` is only used for automated smoke tests."""
+
+        frame_count = 0
+        while self.running and (max_frames is None or frame_count < max_frames):
+            dt = min(self.clock.tick(FPS) / 1000.0, 0.05)
+
+            if self.state == "startscreen":
+                next_state = self.startscreen.run()
+                if next_state == "quit":
+                    self.running = False
+                elif next_state == "game":
+                    self.player_name = self.startscreen.player_name
+                    self.state = "game"
+            elif self.state == "game":
+                self.handle_events()
+                self.update(dt)
+                self.draw()
+
+
+            pygame.display.flip()
+            frame_count += 1
+
+        pygame.quit()
+
+    def handle_events(self) -> None:
+        for event in pygame.event.get():
+            if event.type == pygame.QUIT:
+                self.running = False
+            elif event.type == pygame.KEYDOWN:
+                if event.key in (pygame.K_ESCAPE, pygame.K_q):
+                    self.running = False
+                elif event.key == pygame.K_SPACE:
+                    self.player.toggle_side()
+
+    def update(self, dt: float) -> None:
+        movement = self.get_player_movement(dt)
+        self.player.move_by(movement)
+
+        if not self.is_position_walkable(self.player.position):
+            self.player.hit_wall()
+
+        self.player.update_animation(dt)
+
+    def get_player_movement(self, dt: float) -> pygame.Vector2:
+        keys = pygame.key.get_pressed()
+        movement = pygame.Vector2(
+            (keys[pygame.K_RIGHT] or keys[pygame.K_d])
+            - (keys[pygame.K_LEFT] or keys[pygame.K_a]),
+            (keys[pygame.K_DOWN] or keys[pygame.K_s])
+            - (keys[pygame.K_UP] or keys[pygame.K_w]),
+        )
+
+        if movement.length_squared() == 0:
+            return movement
+
+        if abs(movement.x) > abs(movement.y):
+            self.player.direction = "right" if movement.x > 0 else "left"
+        else:
+            self.player.direction = "down" if movement.y > 0 else "up"
+
+        return movement.normalize() * PLAYER_SPEED * dt
+
+    def is_position_walkable(self, position: pygame.Vector2) -> bool:
+        """Check if the actor's feet are standing on a walkable map tile."""
+
+        column = int(position.x // tile_size)
+        row = int(position.y // tile_size)
+        return self.map.is_accessible(column, row)
+
+    def find_start_position(self) -> tuple[int, int]:
+        """Find the first S tile and place the actor's feet near its center."""
+
+        for row_index, row in enumerate(self.map.map):
+            column_index = row.find("S")
+            if column_index != -1:
+                # The S tile is at the very top of the current map, so place the
+                # actor one tile lower to keep the sprite visible on screen.
+                return (
+                    column_index * tile_size + tile_size // 2,
+                    (row_index + 1) * tile_size + tile_size // 2,
+                )
+
+        return tile_size, tile_size
+
+    def draw(self) -> None:
+        self.screen.fill(color_void)
+        self.map.draw_map(self.screen, self.font)
+
+
+        # Draw by Y position so actors lower on the map appear in front.
+        for actor in sorted([self.player], key=lambda item: item.position.y):
+            actor.draw(self.screen)
+

src/settings.py

@@ -1,6 +1,8 @@
 # --- DESK ---
 from typing import Mapping, Literal, Tuple
 
+from src.map import tile_size
+
 DESK_WIDTH = 70
 DESK_HEIGHT = 40
 
@@ -30,7 +32,7 @@ DIRECTION_FRAMES: Mapping[Direction, Tuple[int, int, int]] = {
 # Default drawing size and animation speed.
 DEFAULT_SPRITE_HEIGHT: int = 138
 DEFAULT_FRAME_TIME: float = 0.16
-=======
+
 
 # --- ECTS ---
 START_ECTS_VALUE = 1        # how many ECTS are generated at the beginning
@@ -91,3 +93,7 @@ COLOR_HP_BAR_YELLOW = (255, 255, 0)
 
 HUD_BAR_WIDTH = 100
 HUD_BAR_HEIGHT = 15
+
+PLAYER_SPEED = 180.0
+DEMO_ACTOR_HEIGHT = tile_size * 3
+FPS = 60

src/startscreen.py

@@ -1,11 +1,13 @@
 import pygame
-from button import Button
-from settings import (COLOR_BUTTON,
-                      COLOR_BUTTON_HOVER,
-                      COLOR_STARTSCREEN_BACKGROUND,
-                      COLOR_STARTSCREEN_FONT_TITLE,
-                      COLOR_STARTSCREEN_FONT_LABEL)
-from text_input import TextInput
+from src.button import Button
+from src.settings import (
+    COLOR_BUTTON,
+    COLOR_BUTTON_HOVER,
+    COLOR_STARTSCREEN_BACKGROUND,
+    COLOR_STARTSCREEN_FONT_TITLE,
+    COLOR_STARTSCREEN_FONT_LABEL,
+)
+from src.text_input import TextInput
 
 class Startscreen:
     def __init__(self, screen):