Merge pull request #30 from SergioRAgostinho/pyglet-opt

Made Pyglet an optional dependency

Author: Kurt Yoder

README.md

@@ -3,13 +3,13 @@ PyWavefront
 
 This python module allows you to read Wavefront 3D object files
 (`something.obj` and `something.mtl`) and use them as Python objects.
-Currently Pyglet is required to render and display these objects.
+If you optionally want to render and display these objects, Pyglet is required.
 
 Currently, only a subset of [the defined
 specification](https://en.wikipedia.org/wiki/Wavefront_.obj_file) has
 been implemented.
 
-Requirements
+Optional Dependencies
 ------------
 
 * [Pyglet](http://www.pyglet.org/)
@@ -19,14 +19,29 @@ Usage
 
 ### From Python
 
-    import pywavefront
-    meshes = pywavefront.Wavefront('something.obj')
-    meshes.draw()
+**Basic**
+
+```python
+import pywavefront
+meshes = pywavefront.Wavefront('something.obj')
+```
+
+**Visualization**
+
+```python
+import pywavefront
+
+[create a window and set up your OpenGl context]
+meshes = pywavefront.Wavefront('something.obj')
+
+[inside your drawing loop]
+meshes.draw()
+```
 
 ### Example Script
 
 There are two pyglet example scripts with included `.obj` and `.mtl` files in the `example` directory. To run them, change to the `example`
-directory and run either `./pyglet_demo.py` or `.pyglet_demo2.py`.
+directory and run either `./pyglet_demo.py` or `.pyglet_demo2.py`. Pyglet is required for these.
 
 ### Generating a Wavefront file with Blender
 

example/pyglet_demo.py

@@ -7,7 +7,7 @@
 import pyglet
 from pyglet.gl import *
 
-import pywavefront
+import pywavefront.visualization
 
 rotation = 0
 

example/pyglet_demo2.py

@@ -9,6 +9,7 @@
 from pyglet.gl import *
 
 from pywavefront import Wavefront
+import pywavefront.visualization
 
 rotation = 0
 

pywavefront/__init__.py

@@ -32,8 +32,6 @@
 # POSSIBILITY OF SUCH DAMAGE.
 # ----------------------------------------------------------------------------
 
-from pyglet.gl import *
-
 import pywavefront.material
 import pywavefront.mesh
 import pywavefront.parser

pywavefront/material.py

@@ -32,8 +32,6 @@
 # POSSIBILITY OF SUCH DAMAGE.
 # ----------------------------------------------------------------------------
 
-from pyglet.gl import *
-
 import pywavefront.parser as parser
 import pywavefront.texture as texture
 
@@ -87,26 +85,12 @@ def unset_texture(self):
         self.texture = None
 
     def gl_light(self, lighting):
-        """Return a GLfloat with length 4, containing the 4 lighting values."""
-        return (GLfloat * 4)(*(lighting))
-
-    def draw(self, face=GL_FRONT_AND_BACK):
-        if self.texture:
-            self.texture.draw()
-        else:
-            glDisable(GL_TEXTURE_2D)
-
-        glMaterialfv(face, GL_DIFFUSE, self.gl_light(self.diffuse))
-        glMaterialfv(face, GL_AMBIENT, self.gl_light(self.ambient))
-        glMaterialfv(face, GL_SPECULAR, self.gl_light(self.specular))
-        glMaterialfv(face, GL_EMISSION, self.gl_light(self.emissive))
-        glMaterialf(face, GL_SHININESS, self.shininess)
-
-        if self.gl_floats is None:
-            self.gl_floats = (GLfloat * len(self.vertices))(*self.vertices)
-            self.triangle_count = len(self.vertices) / 8
-        glInterleavedArrays(GL_T2F_N3F_V3F, 0, self.gl_floats)
-        glDrawArrays(GL_TRIANGLES, 0, int(self.triangle_count))
+        """Method placeholder"""
+        raise Exception("Please import pywavefront.visualization")
+
+    def draw(self, face=None):
+        """Method placeholder"""
+        raise Exception("Please import pywavefront.visualization")
 
 
 class MaterialParser(parser.Parser):

pywavefront/mesh.py

@@ -32,9 +32,6 @@
 # POSSIBILITY OF SUCH DAMAGE.
 # ----------------------------------------------------------------------------
 
-from pyglet.gl import *
-
-
 class Mesh(object):
     """This is a basic mesh for drawing using OpenGL. Interestingly, it does
     not contain its own vertices. These are instead drawn via materials."""
@@ -55,11 +52,5 @@ def add_material(self, material):
         self.materials.append(material)
 
     def draw(self):
-        glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT)
-        glPushAttrib(GL_CURRENT_BIT | GL_ENABLE_BIT | GL_LIGHTING_BIT)
-        glEnable(GL_CULL_FACE)
-        glCullFace(GL_BACK)
-        for material in self.materials:
-            material.draw()
-        glPopAttrib()
-        glPopClientAttrib()
+        """Method placeholder"""
+        raise Exception("Please import pywavefront.visualization")

pywavefront/parser.py

@@ -33,7 +33,6 @@
 # ----------------------------------------------------------------------------
 
 import os
-import pyglet
 import logging
 
 class Parser(object):

pywavefront/texture.py

@@ -32,22 +32,23 @@
 # POSSIBILITY OF SUCH DAMAGE.
 # ----------------------------------------------------------------------------
 
-from pyglet.gl import *
-
+import os
 
 class Texture(object):
     def __init__(self, path):
         self.image_name = path
-        self.image = pyglet.image.load(self.image_name).texture
-        self.verify_dimensions()
+        self.image = None
+
+        if not os.path.exists(path):
+            raise Exception("Requested file does not exist")
 
     def draw(self):
-        glEnable(self.image.target)
-        glBindTexture(self.image.target, self.image.id)
-        gl.glTexParameterf(self.image.target,
-                           gl.GL_TEXTURE_WRAP_S, gl.GL_CLAMP)
-        gl.glTexParameterf(self.image.target,
-                           gl.GL_TEXTURE_WRAP_T, gl.GL_CLAMP)
+        """Method placeholder"""
+        raise Exception("Please import pywavefront.visualization")
+
+    def load_image(self):
+        """Method placeholder"""
+        raise Exception("Please import pywavefront.visualization")
 
     def verify_dimensions(self):
         self.verify('width')

pywavefront/visualization.py

@@ -0,0 +1,117 @@
+# ----------------------------------------------------------------------------
+# PyWavefront
+# Copyright (c) 2018 Kurt Yoder
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+#  * Neither the name of PyWavefront nor the names of its
+#    contributors may be used to endorse or promote products
+#    derived from this software without specific prior written
+#    permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+# ----------------------------------------------------------------------------
+
+from pyglet.gl import *
+
+from pywavefront.material import Material
+from pywavefront.mesh import Mesh
+from pywavefront.texture import Texture
+
+class _Material(object):
+    """
+    Overrides the drawing routines for the Material class.
+    This class should not be used directly. Its purpose is to shadow
+    the methods to be overriden.
+    """
+
+    def gl_light(self, lighting):
+        """Return a GLfloat with length 4, containing the 4 lighting values."""
+        return (GLfloat * 4)(*(lighting))
+
+    def draw(self, face=GL_FRONT_AND_BACK):
+        if self.texture:
+            self.texture.draw()
+        else:
+            glDisable(GL_TEXTURE_2D)
+
+        glMaterialfv(face, GL_DIFFUSE, self.gl_light(self.diffuse))
+        glMaterialfv(face, GL_AMBIENT, self.gl_light(self.ambient))
+        glMaterialfv(face, GL_SPECULAR, self.gl_light(self.specular))
+        glMaterialfv(face, GL_EMISSION, self.gl_light(self.emissive))
+        glMaterialf(face, GL_SHININESS, self.shininess)
+
+        if self.gl_floats is None:
+            self.gl_floats = (GLfloat * len(self.vertices))(*self.vertices)
+            self.triangle_count = len(self.vertices) / 8
+        glInterleavedArrays(GL_T2F_N3F_V3F, 0, self.gl_floats)
+        glDrawArrays(GL_TRIANGLES, 0, int(self.triangle_count))
+
+
+setattr(Material, "gl_light", _Material.gl_light)
+setattr(Material, "draw", _Material.draw)
+
+
+class _Mesh(object):
+    """
+    Overrides the drawing routines for the Mesh class.
+    This class should not be used directly. Its purpose is to shadow
+    the methods to be overriden.
+    """
+    def draw(self):
+        glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT)
+        glPushAttrib(GL_CURRENT_BIT | GL_ENABLE_BIT | GL_LIGHTING_BIT)
+        glEnable(GL_CULL_FACE)
+        glCullFace(GL_BACK)
+        for material in self.materials:
+            material.draw()
+        glPopAttrib()
+        glPopClientAttrib()
+
+setattr(Mesh, "draw", _Mesh.draw)
+
+
+class _Texture(object):
+
+    def init(self, path):
+        self.image_name = path
+        self.load_image()
+
+    def draw(self):
+        if not self.image:
+            self.load_image()
+
+        glEnable(self.image.target)
+        glBindTexture(self.image.target, self.image.id)
+        gl.glTexParameterf(self.image.target,
+                           gl.GL_TEXTURE_WRAP_S, gl.GL_CLAMP)
+        gl.glTexParameterf(self.image.target,
+                           gl.GL_TEXTURE_WRAP_T, gl.GL_CLAMP)
+
+    def load_image(self):
+        self.image = pyglet.image.load(self.image_name).texture
+        self.verify_dimensions()
+
+setattr(Texture, "__init__", _Texture.init)
+setattr(Texture, "draw", _Texture.draw)
+setattr(Texture, "load_image", _Texture.load_image)

requirements.txt

@@ -1 +0,0 @@
-pyglet