koperkapel/scenes/level.py

   1 """Render a level"""
   2
   3 from pgzero.constants import keys
   4 from pygame import Surface
   5 import pygame.locals as pgl
   6 from ..loaders.levelloader import levels
   7 from .base import Scene, ChangeSceneEvent
   8 from ..constants import TILE_SIZE, WIDTH, HEIGHT
   9
  10
  11 class BaseLevelScene(Scene):
  12     """ Level scene. """
  13
  14     def enter(self, world):
  15         self._level_data = levels.load(world.level.name)
  16         self._tiles = self._level_data['tiles']
  17         self._level_layer = 'floor'
  18         self._surfaces = {}
  19         self._overlay = {}
  20         for layer in ['floor', 'tunnels']:
  21             self._surfaces[layer] = self._render(layer)
  22         self._overlay = self._surfaces['floor'].copy()
  23
  24     def _render(self, layer):
  25         # We cache the rendered surface to avoid doing a large number
  26         # of blits each frame, as that introduces a large performance
  27         # overhead.
  28         surface = Surface((len(self._tiles[0]) * TILE_SIZE,
  29                            len(self._tiles) * TILE_SIZE))
  30         layer_key = '%s image' % layer
  31         for y, row in enumerate(self._tiles):
  32             for x, tile in enumerate(row):
  33                 pos = (x * TILE_SIZE, y * TILE_SIZE)
  34                 if layer_key not in tile:
  35                     # Skip broken tiles for now
  36                     continue
  37                 surface.blit(tile[layer_key], pos)
  38         return surface.convert_alpha()
  39
  40     def draw(self, screen, viewport):
  41         screen.clear()
  42         # Viewport is the position of the screen relative to the
  43         # surface. We need the position of the surface relative to
  44         # the screen for the blit, so this conversion
  45         screen.surface.blit(self._surfaces[self._level_layer], (0, 0),
  46                             area=(viewport[0], viewport[1], WIDTH, HEIGHT))
  47         if self._level_layer != 'floor':
  48             screen.surface.blit(self._overlay, (0, 0),
  49                          area=(viewport[0], viewport[1], WIDTH, HEIGHT),
  50                          special_flags=pgl.BLEND_ADD)
  51
  52     def on_key_down(self, key, mod, unicode):
  53         if key == keys.ESCAPE:
  54             from .menu import MenuScene
  55             return [ChangeSceneEvent(MenuScene())]
  56
  57
  58 class GameLevelScene(BaseLevelScene):
  59     pass