"""Darwin (MacOSX)-specific platform features
This was implemented with the help of the following links:
[1] Apple's Mac OS X OpenGL interfaces: http://developer.apple.com/qa/qa2001/qa1269.html
[2] As above, but updated: http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_pg_concepts/chapter_2_section_3.html
[3] CGL reference: http://developer.apple.com/documentation/GraphicsImaging/Reference/CGL_OpenGL/index.html#//apple_ref/doc/uid/TP40001186
[4] Intro to OpenGL on Mac OS X: http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_intro/chapter_1_section_1.html#//apple_ref/doc/uid/TP40001987-CH207-TP9
About the CGL API, (from [1]):
CGL or Core OpenGL is the lowest accessible interface API for OpenGL.
It knows nothing about windowing systems but can be used directly to
find both renderer information and as a full screen or off screen
interface. It is accessible from both Cocoa and Carbon and is what both
NSGL and AGL are built on. A complete Pbuffer interface is also provided.
Functionality is provided in via the OpenGL framework and applications
can include the OpenGL.h header to access CGL's functionality. Developers
can see an example of using CGL with Carbon in the Carbon CGL code sample.
Documentation and header files are found in:
/System/Library/Frameworks/OpenGL.framework
/System/Library/Frameworks/GLUT.framework
"""
import ctypes, ctypes.util
from OpenGL.platform import baseplatform,ctypesloader
class DarwinPlatform( baseplatform.BasePlatform ):
"""Darwin (OSX) platform implementation"""
DEFAULT_FUNCTION_TYPE = staticmethod( ctypes.CFUNCTYPE )
EXTENSIONS_USE_BASE_FUNCTIONS = True
# Get the pointers to the libraries...
try:
OpenGL = ctypesloader.loadLibrary(
ctypes.cdll,
'OpenGL',
mode=ctypes.RTLD_GLOBAL
)
except OSError, err:
raise ImportError("Unable to load OpenGL library", *err.args)
# CGL provides the windowing environment functionality
# but it is built into the GL libs.
GL = GLU = CGL = OpenGL
# glut shouldn't need to be global, but just in case a dependent library makes
# the same assumption GLUT does...
GLUT = ctypesloader.loadLibrary(
ctypes.cdll,
'GLUT',
mode=ctypes.RTLD_GLOBAL
)
# GLE is handled by GLUT under OS X
GLE = GLUT
GetCurrentContext = CurrentContextIsValid = staticmethod(
CGL.CGLGetCurrentContext
)
def getGLUTFontPointer( self, constant ):
"""Platform specific function to retrieve a GLUT font pointer
GLUTAPI void *glutBitmap9By15;
#define GLUT_BITMAP_9_BY_15 (&glutBitmap9By15)
Key here is that we want the addressof the pointer in the DLL,
not the pointer in the DLL. That is, our pointer is to the
pointer defined in the DLL, we don't want the *value* stored in
that pointer.
"""
name = [ x.title() for x in constant.split( '_' )[1:] ]
internal = 'glut' + "".join( [x.title() for x in name] )
pointer = ctypes.c_void_p.in_dll( self.GLUT, internal )
return ctypes.c_void_p(ctypes.addressof(pointer))
def safeGetError( self ):
"""Provide context-not-present-safe error-checking
Under OS-X an attempt to retrieve error without checking
context will bus-error. This function checks for a valid
context before running glGetError
Note:
This is a likely candidate for rewriting in C, as it
is called for every almost function in the system!
"""
if self.CurrentContextIsValid():
return glGetError()
return None
glGetError = DarwinPlatform.OpenGL.glGetError
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