pybullet: added EGL render device and window_backend option.

EGL review.
EGL dynamic loading, windowType to int
moved to glad2
Require GL 3.3 as GLInstancingRenderer.cpp uses glVertexAttribDivisor
glad2 update with dynamic X11 added
removed old file
build fix
fix mac/win
EGL w/o c++11, off by default
fix premake
fixup: premake fix 2

setup.py

@@ -22,7 +22,7 @@ CXX_FLAGS += '-DBT_USE_DOUBLE_PRECISION '
 CXX_FLAGS += '-DBT_ENABLE_ENET '
 CXX_FLAGS += '-DBT_ENABLE_CLSOCKET '
 CXX_FLAGS += '-DB3_DUMP_PYTHON_VERSION '
-
+#CXX_FLAGS += '-DBT_USE_EGL '  # uncomment for EGL (old EGL versions fail)
 
 
 # libraries += [current_python]
@@ -386,28 +386,34 @@ sources = ["examples/pybullet/pybullet.c"]\
 +["examples/ThirdPartyLibs/Gwen/Renderers/OpenGL_DebugFont.cpp"]\
 
 if _platform == "linux" or _platform == "linux2":
-    libraries = ['dl','pthread']
+    libraries += ['dl','pthread']
     CXX_FLAGS += '-D_LINUX '
     CXX_FLAGS += '-DGLEW_STATIC '
     CXX_FLAGS += '-DGLEW_INIT_OPENGL11_FUNCTIONS=1 '
     CXX_FLAGS += '-DGLEW_DYNAMIC_LOAD_ALL_GLX_FUNCTIONS=1 '
     CXX_FLAGS += '-DDYNAMIC_LOAD_X11_FUNCTIONS '
     CXX_FLAGS += '-DHAS_SOCKLEN_T '
-    CXX_FLAGS += '-fno-inline-functions-called-once'
+    CXX_FLAGS += '-fno-inline-functions-called-once '
     sources = sources + ["examples/ThirdPartyLibs/enet/unix.c"]\
     +["examples/OpenGLWindow/X11OpenGLWindow.cpp"]\
-    +["examples/ThirdPartyLibs/glad/glad.c"]\
-    +["examples/ThirdPartyLibs/glad/glad_glx.c"]
+    +["examples/ThirdPartyLibs/glad/gl.c"]\
+    +["examples/ThirdPartyLibs/glad/glx.c"]
     include_dirs += ["examples/ThirdPartyLibs/optionalX11"]
+    if 'BT_USE_EGL' in CXX_FLAGS:
+        # linking with bullet's Glew libraries causes segfault
+        # for some reason.
+        sources += ['examples/ThirdPartyLibs/glad/egl.c']
+        sources += ['examples/OpenGLWindow/EGLOpenGLWindow.cpp']
+
 elif _platform == "win32":
     print("win32!")
-    libraries = ['Ws2_32','Winmm','User32','Opengl32','kernel32','glu32','Gdi32','Comdlg32']
+    libraries += ['Ws2_32','Winmm','User32','Opengl32','kernel32','glu32','Gdi32','Comdlg32']
     CXX_FLAGS += '-DWIN32 '
     CXX_FLAGS += '-DGLEW_STATIC '
     sources = sources + ["examples/ThirdPartyLibs/enet/win32.c"]\
     +["examples/OpenGLWindow/Win32Window.cpp"]\
     +["examples/OpenGLWindow/Win32OpenGLWindow.cpp"]\
-    +["examples/ThirdPartyLibs/glad/glad.c"]
+    +["examples/ThirdPartyLibs/glad/gl.c"]
 elif _platform == "darwin":
     print("darwin!")
     os.environ['LDFLAGS'] = '-framework Cocoa -framework OpenGL'
@@ -417,11 +423,11 @@ elif _platform == "darwin":
 #    CXX_FLAGS += '-framework Cocoa '
     sources = sources + ["examples/ThirdPartyLibs/enet/unix.c"]\
     +["examples/OpenGLWindow/MacOpenGLWindow.cpp"]\
-    +["examples/ThirdPartyLibs/glad/glad.c"]\
+    +["examples/ThirdPartyLibs/glad/gl.c"]\
     +["examples/OpenGLWindow/MacOpenGLWindowObjC.m"]
 else:
     print("bsd!")
-    libraries = ['GL','GLEW','pthread']
+    libraries += ['GL','GLEW','pthread']
     os.environ['LDFLAGS'] = '-L/usr/X11R6/lib'
     CXX_FLAGS += '-D_BSD '
     CXX_FLAGS += '-I/usr/X11R6/include '
@@ -429,7 +435,7 @@ else:
     CXX_FLAGS += '-fno-inline-functions-called-once'
     sources = ["examples/ThirdPartyLibs/enet/unix.c"]\
     +["examples/OpenGLWindow/X11OpenGLWindow.cpp"]\
-    +["examples/ThirdPartyLibs/glad/glad.c"]\
+    +["examples/ThirdPartyLibs/glad/gl.c"]\
     + sources
 
 setup_py_dir = os.path.dirname(os.path.realpath(__file__))
@@ -463,7 +469,7 @@ setup(
 	license='zlib',
 	platforms='any',
 	keywords=['game development', 'virtual reality', 'physics simulation', 'robotics', 'collision detection', 'opengl'],
-	ext_modules = [Extension("pybullet", 
+	ext_modules = [Extension("pybullet",
 	sources =  sources,
 	libraries = libraries,
 	extra_compile_args=CXX_FLAGS.split(),