"""ctypes data-pointers as a data-format mechanism
"""
REGISTRY_NAME = 'ctypespointers'
import ctypes, _ctypes
from OpenGL import constants,constant
from OpenGL.arrays import formathandler
import operator
class CtypesPointerHandler( formathandler.FormatHandler ):
"""Ctypes Pointer-type-specific data-type handler for OpenGL
Because pointers do not have size information we can't use
them for output of data, but they can be used for certain
types of input...
"""
@classmethod
def from_param( cls, value, typeCode=None ):
return value
dataPointer = staticmethod( ctypes.addressof )
HANDLED_TYPES = (ctypes._Pointer, )
def voidDataPointer( cls, value ):
"""Given value in a known data-pointer type, return void_p for pointer"""
return ctypes.cast( value, ctypes.c_void_p )
def zeros( self, dims, typeCode ):
"""Return Numpy array of zeros in given size"""
raise NotImplementedError( """Sized output doesn't yet work...""" )
def ones( self, dims, typeCode='d' ):
"""Return numpy array of ones in given size"""
raise NotImplementedError( """Haven't got a good ones implementation yet""" )
def arrayToGLType( self, value ):
"""Given a value, guess OpenGL type of the corresponding pointer"""
result = ARRAY_TO_GL_TYPE_MAPPING.get( value._type_ )
if result is not None:
return result
raise TypeError(
"""Don't know GL type for array of type %r, known types: %s\nvalue:%s"""%(
value._type_, ARRAY_TO_GL_TYPE_MAPPING.keys(), value,
)
)
def arraySize( self, value, typeCode = None ):
"""Given a data-value, calculate dimensions for the array"""
raise NotImplementedError( """Haven't got an arraySize implementation""" )
def asArray( self, value, typeCode=None ):
"""Convert given value to an array value of given typeCode"""
return value
def unitSize( self, value, typeCode=None ):
"""Determine unit size of an array (if possible)"""
return 1
def dimensions( self, value, typeCode=None ):
"""Determine dimensions of the passed array value (if possible)"""
raise NotImplementedError( """Haven't got a dimensions implementation""" )
ARRAY_TO_GL_TYPE_MAPPING = {
constants.GLdouble: constants.GL_DOUBLE,
constants.GLfloat: constants.GL_FLOAT,
constants.GLint: constants.GL_INT,
constants.GLuint: constants.GL_UNSIGNED_INT,
constants.GLshort: constants.GL_SHORT,
constants.GLushort: constants.GL_UNSIGNED_SHORT,
constants.GLchar: constants.GL_CHAR,
constants.GLbyte: constants.GL_BYTE,
constants.GLubyte: constants.GL_UNSIGNED_BYTE,
}
GL_TYPE_TO_ARRAY_MAPPING = {
constants.GL_DOUBLE: constants.GLdouble,
constants.GL_FLOAT: constants.GLfloat,
constants.GL_INT: constants.GLint,
constants.GL_UNSIGNED_INT: constants.GLuint,
constants.GL_SHORT: constants.GLshort,
constants.GL_UNSIGNED_SHORT: constants.GLushort,
constants.GL_CHAR: constants.GLchar,
constants.GL_BYTE: constants.GLbyte,
constants.GL_UNSIGNED_BYTE: constants.GLubyte,
}
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