Soya/Python sauvegarde avec cerealizer

# -*- indent-tabs-mode: t -*-

# Soya 3D tutorial
# Copyright (C) 2001-2004 Jean-Baptiste LAMY
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA


# base de sauvegarde de fichier avec céréalizer : Sauvez un fichier avec cerealizer : 
# sauvez un corps en rotation.

# Cette leçon enregistre le moèle tournant de la leçon base 2 dans un fichier en utilisant Cerealizer.
# Pour commencer, vous devez installer Cerealizer (un module semblable à Pickle), 
# il est disponible sur cette page :
#
# http://home.gna.org/oomadness/en/cerealizer/index.html


# Importation de Soya et Cerealizer.

import sys, os, os.path, soya
import cerealizer


# Création de la classe du corps en rotation, regardez le tutorial base 2 pour plus d'information.
# Notez que vous pouvez ajouter un attribut à votre classe, et il sera automatiquement sauvé.

class RotatingBody(soya.Body):
        def advance_time(self, proportion):
                soya.Body.advance_time(self, proportion)
                
                self.rotate_y(proportion * 5.0)

# Enregistrement de la classe RotatingBody en utilisant Cerealizer.

cerealizer.register(RotatingBody)

# cerealizer.register accepte toutes les classes de Python. Une classe peut hériter d'une classe Soya
# (tel que, ici, Body) ou non, ce n'est pas important.
# Cependant, si votre classe hérite de World, Image, Model, Material, vous devez faire quelque chose
# de spécial si vous voulez utiliser YourClass.get() ou YourClass.save(). Ceci implique 
# l'objet SavedInAPath, comprendre ici que tous les objets Soya sont sauvés 
# dans un répertoire spécial de soya.path.
#
# Par contre, pour World, vous devez faire ceci :
#
#import soya.cerealizer4soya
#class YourWorld(soya.World):
# pass
#cerealizer.register(YourWorld, soya.cerealizer4soya.SavedInAPathHandler(YourWorld))
#
# Et vous pouvez utiliser YourWorld.get("filename").
#
# Si vous désirez qu'un fichier soit sauvé dans un sous répertoire différent de soya.path, par exemple
# data/your_worlds/ plutot que data/worlds/, faites:
#
#class YourWorld(soya.World):
# DIRNAME = "your_worlds"



# The rest of the file is executed ONLY if this file is run as a script.
# This allows to import this file as a module, for defining the RotatingBody class.

if sys.argv[0].endswith("basic-savingfile-cerealizer-1.py"):
        # Inits Soya and sets the data directory.
        
        soya.init()
        soya.path.append(os.path.join(os.path.dirname(sys.argv[0]), "data"))
        
        # Sets the file format soya uses for saving file.
        #
        # The default configuration is to use cPickle for saving files, and to support loading
        # files saved either by cPickle or Cerealizer (if available).
        #
        # The complete syntax is set_file_format(saving_format, loading_format), where loading_format
        # is optional and can be either a single format, or a list of format.
        # There are currently 2 supported formats: cPickle and Cerealizer.
        # See set_file_format's __doc__ for more information.
        
        soya.set_file_format(cerealizer)

        # Creates the scene.

        scene = soya.World()

        # Loads the sword model.

        sword_model = soya.Model.get("sword")


        # Creates a rotating body in the scene, using the sword model.

        sword = RotatingBody(scene, sword_model)

        # Creates a light.

        light = soya.Light(scene)
        light.set_xyz(0.5, 0.0, 2.0)

        # Set the scene filename. It is just the name of the file, soya adds automatically
        # a directory path as well as a ".data" extention.

        scene.filename = "a_scene_with_a_rotating_body"

        # Saves the scene. The file is created in the <soya.path[0]>/worlds/ directory, here:
        #
        #          tutorial/data/worlds/a_scene_with_a_rotating_body.data
        #
        # The file is ALWAYS saved in the FIRST path listed in soya.path (which is, as sys.path,
        # a list of path).
        #
        # Soya separates the "set filename" and the "save" step, because it allows you to set the
        # filename once, and then to save the object several times without having to remind its
        # filename.
        #
        # Notice that, while saving the scene, Soya will save a reference to the "sword" Model we
        # have used above. However, the data of this Model are NOT dupplicated.

        scene.save()

        # Creates a camera.
        #
        # For technical reasons, camera are not saveable yet. This is not really a problem since the
        # camera is not really scene-dependent by rather configuration-dependent.
        # We thus add the camera AFTER saving the scene.

        camera = soya.Camera(scene)
        camera.z = 3.0
        soya.set_root_widget(camera)

        soya.MainLoop(scene).main_loop()

        # That's all -- after running this tutorial, you should have a
        # tutorial/data/worlds/a_scene_with_a_rotating_body.data file. The easiest way to verify
        # that this file is REALLY a Cerealizer file, is to open the file and check if it begins
        # by the magic string "cereal1".