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"""String-array-handling code for PyOpenGL
"""
#from OpenGL.arrays._strings import dataPointer as old
from OpenGL import constants
from OpenGL.arrays import formathandler
import ctypes
psas = ctypes.pythonapi.PyString_AsString
# it's a c_char_p, but if we use that then the code will
# attempt to use null-terminated versus arbitrarily sized
psas.restype = ctypes.c_size_t
#psas.restype = ctypes.c_char_p
def dataPointer( value, typeCode=None ):
new = psas( ctypes.py_object(value) )
return new
class StringHandler( formathandler.FormatHandler ):
"""String-specific data-type handler for OpenGL"""
HANDLED_TYPES = (str, )
@classmethod
def from_param( cls, value, typeCode=None ):
return ctypes.c_void_p( dataPointer( value ) )
dataPointer = staticmethod( dataPointer )
def zeros( self, dims, typeCode=None ):
"""Currently don't allow strings as output types!"""
raise NotImplemented( """Don't currently support strings as output arrays""" )
def ones( self, dims, typeCode=None ):
"""Currently don't allow strings as output types!"""
raise NotImplemented( """Don't currently support strings as output arrays""" )
def arrayToGLType( self, value ):
"""Given a value, guess OpenGL type of the corresponding pointer"""
raise NotImplemented( """Can't guess data-type from a string-type argument""" )
def arraySize( self, value, typeCode = None ):
"""Given a data-value, calculate ravelled size for the array"""
# need to get bits-per-element...
byteCount = BYTE_SIZES[ typeCode ]
return len(value)//byteCount
def arrayByteCount( self, value, typeCode = None ):
"""Given a data-value, calculate number of bytes required to represent"""
return len(value)
def asArray( self, value, typeCode=None ):
"""Convert given value to an array value of given typeCode"""
if isinstance( value, str ):
return value
elif hasattr( value, 'tostring' ):
return value.tostring()
elif hasattr( value, 'raw' ):
return value.raw
# could convert types to string here, but we're not registered for
# anything save string types...
raise TypeError( """String handler got non-string object: %r"""%(type(value)))
def dimensions( self, value, typeCode=None ):
"""Determine dimensions of the passed array value (if possible)"""
raise TypeError(
"""Cannot calculate dimensions for a String data-type"""
)
BYTE_SIZES = {
constants.GL_DOUBLE: ctypes.sizeof( constants.GLdouble ),
constants.GL_FLOAT: ctypes.sizeof( constants.GLfloat ),
constants.GL_INT: ctypes.sizeof( constants.GLint ),
constants.GL_SHORT: ctypes.sizeof( constants.GLshort ),
constants.GL_UNSIGNED_BYTE: ctypes.sizeof( constants.GLubyte ),
constants.GL_UNSIGNED_SHORT: ctypes.sizeof( constants.GLshort ),
constants.GL_BYTE: ctypes.sizeof( constants.GLbyte ),
constants.GL_UNSIGNED_INT: ctypes.sizeof( constants.GLuint ),
}
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