Split level scene for game play extensions

[koperkapel.git] / koperkapel / scenes / level.py

diff --git a/koperkapel/scenes/level.py b/koperkapel/scenes/level.py
index a58c51d450ee3d8b04200e138b0687f3fef60f30..9a8fdc36957459a8fcc80465912c1330f5ec46ec 100644 (file)
--- a/koperkapel/scenes/level.py
+++ b/koperkapel/scenes/level.py
@@ -1,29 +1,59 @@
 """Render a level"""
 
 from pgzero.constants import keys
+from pygame import Surface
+import pygame.locals as pgl
 from ..loaders.levelloader import levels
 from .base import Scene, ChangeSceneEvent
-from .constants import TILE_SIZE
+from ..constants import TILE_SIZE, WIDTH, HEIGHT
 
 
-class LevelScene(Scene):
+class BaseLevelScene(Scene):
     """ Level scene. """
 
-    def __init__(self, level_name):
-        self._level_data = levels.load(level_name)
+    def enter(self, world):
+        self._level_data = levels.load(world.level.name)
         self._tiles = self._level_data['tiles']
+        self._level_layer = 'floor'
+        self._surfaces = {}
+        self._overlay = {}
+        for layer in ['floor', 'tunnels']:
+            self._surfaces[layer] = self._render(layer)
+        self._overlay = self._surfaces['floor'].copy()
 
-    def draw(self, screen):
+    def _render(self, layer):
+        # We cache the rendered surface to avoid doing a large number
+        # of blits each frame, as that introduces a large performance
+        # overhead.
+        surface = Surface((len(self._tiles[0]) * TILE_SIZE,
+                           len(self._tiles) * TILE_SIZE))
+        layer_key = '%s image' % layer
+        for y, row in enumerate(self._tiles):
+            for x, tile in enumerate(row):
+                pos = (x * TILE_SIZE, y * TILE_SIZE)
+                if layer_key not in tile:
+                    # Skip broken tiles for now
+                    continue
+                surface.blit(tile[layer_key], pos)
+        return surface.convert_alpha()
+
+    def draw(self, screen, viewport):
         screen.clear()
-        for tile in self._tiles:
-            pos = tile['pos']
-            pos = [pos[0] * TILE_SIZE, pos[1] * TILE_SIZE]
-            if 'image' not in tile:
-                # Skip broken tiles for now
-                continue
-            screen.blit(tile['image'], pos)
+        # Viewport is the position of the screen relative to the
+        # surface. We need the position of the surface relative to
+        # the screen for the blit, so this conversion
+        screen.surface.blit(self._surfaces[self._level_layer], (0, 0),
+                            area=(viewport[0], viewport[1], WIDTH, HEIGHT))
+        if self._level_layer != 'floor':
+            screen.surface.blit(self._overlay, (0, 0),
+                         area=(viewport[0], viewport[1], WIDTH, HEIGHT), 
+                         special_flags=pgl.BLEND_ADD)
 
     def on_key_down(self, key, mod, unicode):
         if key == keys.ESCAPE:
             from .menu import MenuScene
             return [ChangeSceneEvent(MenuScene())]
+
+
+class GameLevelScene(BaseLevelScene):
+    pass