From f27c8eb2e7f39129b2ac9968e77b4a7abbb9250f Mon Sep 17 00:00:00 2001
From: Sakse Dalum <don.s@artescient.at>
Date: Wed, 8 Aug 2012 14:52:08 +0200
Subject: [PATCH] Added translucency.

---
 robotgame/block.py       | 10 ++++++++++
 robotgame/game.py        |  2 +-
 robotgame/level.py       |  7 +++++--
 robotgame/player.py      |  6 ++++--
 robotgame/tile.py        |  2 +-
 robotgame/worldobject.py | 18 ++++++++++++++++++
 6 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/robotgame/block.py b/robotgame/block.py
index 1bf3bb4..7cc8984 100644
--- a/robotgame/block.py
+++ b/robotgame/block.py
@@ -24,6 +24,8 @@
 A generic block.
 """
 
+import pygame
+
 import worldobject
 
 class Block(worldobject.WorldObject):
@@ -31,6 +33,14 @@ class Block(worldobject.WorldObject):
         self.__dict__.update(locals())
         worldobject.WorldObject.__init__(self, level, x, y, movable=movable)
 
+        self.orig_alpha = pygame.surfarray.array_alpha(self.img)
+
+    def update_alpha(self):
+        if (self.y + self.z >= self.level.player.y + self.level.player.z):
+            self.set_alpha(0.5)
+        else:
+            self.set_alpha(1)
+
     def use(self, obj):
         if obj == self.holder:
             obj.holding = None
diff --git a/robotgame/game.py b/robotgame/game.py
index f9b85bd..7f6ddd0 100644
--- a/robotgame/game.py
+++ b/robotgame/game.py
@@ -106,7 +106,7 @@ class Game(object):
         """
         Draw all game objects.
         """
-        self.window.fill((0, 0, 0))
+        self.window.fill((0, 255, 255))
         for obj in self.objs:
             if hasattr(obj, 'draw'):
                 obj.draw(self.window)
diff --git a/robotgame/level.py b/robotgame/level.py
index 2896285..42ac652 100644
--- a/robotgame/level.py
+++ b/robotgame/level.py
@@ -49,10 +49,13 @@ class Level(object):
         if not self.paused:
             for obj in self.objects:
                 obj.update(e, t, dt)
+                if hasattr(obj, 'update_alpha'):
+                    obj.update_alpha()
+
 
         screen_size = self.game.window.get_size()
-        self.camera_x = self.player.x - screen_size[0] / 2
-        self.camera_y = self.player.y - screen_size[1] / 2
+        self.camera_x = (self.player.x - screen_size[0] / 2 + 32)
+        self.camera_y = (self.player.y - screen_size[1] / 2 - 24)
 
     def draw(self, window):
         for tile in self.tiles:
diff --git a/robotgame/player.py b/robotgame/player.py
index e4da179..631b993 100644
--- a/robotgame/player.py
+++ b/robotgame/player.py
@@ -36,12 +36,12 @@ class Player(worldobject.WorldObject):
         worldobject.WorldObject.__init__(self, level, x, y,
                                          z=z, movable=movable)
 
-        self.load()
-
         self.anim = 'idle_right'
         self.frame = 0
         self.anim_speed = 15
 
+        self.load()
+
     def load(self):
         self.imgs = {}
 
@@ -72,6 +72,7 @@ class Player(worldobject.WorldObject):
 
                 self.imgs[anim].append(img)
 
+        self.img = self.imgs[self.anim][int(self.frame)]
 
     def touch(self, touch_x, touch_y):
         for obj in self.level.objects:
@@ -115,6 +116,7 @@ class Player(worldobject.WorldObject):
 
     def draw(self, window):
         self.img = self.imgs[self.anim][int(self.frame)]
+        self.img.set_alpha(128)
         window.blit(self.img, (self.x - 32 - self.level.camera_x,
                                self.y - self.img.get_size()[1] + 24
                                - self.level.camera_y))
diff --git a/robotgame/tile.py b/robotgame/tile.py
index 8d5fa31..59950e8 100644
--- a/robotgame/tile.py
+++ b/robotgame/tile.py
@@ -33,5 +33,5 @@ class Tile(worldobject.WorldObject):
 
     def draw(self, window):
         window.blit(self.img, (self.x - 32 - self.level.camera_x,
-                               self.y - self.img.get_size()[1]
+                               self.y - self.img.get_size()[1] + 24
                                - self.level.camera_y))
diff --git a/robotgame/worldobject.py b/robotgame/worldobject.py
index fff14ec..6c59361 100644
--- a/robotgame/worldobject.py
+++ b/robotgame/worldobject.py
@@ -24,6 +24,10 @@
 A generic world object.
 """
 
+import pygame
+import numpy
+import copy
+
 class WorldObject(object):
     def __init__(self, level, x, y, z=0, direction=(1, 0), speed=5,
                  tile_x=64, tile_y=48,
@@ -36,6 +40,9 @@ class WorldObject(object):
         self.holding = None
         self.holder = None
 
+        if hasattr(self, 'img'):
+            self.img = copy.copy(self.img)
+
     def set_init_pos(self):
         self.init_x, self.init_y = self.x, self.y
 
@@ -69,6 +76,17 @@ class WorldObject(object):
     def use(self):
         pass
 
+    def set_alpha(self, value):
+        """
+        Set the relative translucency of the per-pixel-alpha image.
+
+        Value between 0 - 1, where 0 is completely transparent and 1 is
+        completely opaque.
+        """
+        if hasattr(self, 'img') and hasattr(self, 'orig_alpha'):
+            alpha = pygame.surfarray.pixels_alpha(self.img)
+            alpha[:] = (self.orig_alpha * value).astype(numpy.uint8)
+
     def update(self, e, t, dt):
         if self.x > self.move_x:
             self.x -= min(self.speed * dt * self.tile_x,