Source Code for Module glitter.arrays.basebuffer

  1  """Base class for buffer objects. 
  2   
  3  @todo: Implement binding as separate object to allow binding buffers to 
  4  different targets. This problem is very similar to rebinding L{Sampler}s to 
  5  different units and should probably be handled in a similar way. 
  6  @todo: Implement slicing with C{glGetBufferSubData}. 
  7  @todo: Remember that C{glBindBuffer} and C{glBindBufferRange}/C{glBindBufferBase} interfer with each other! 
  8   
  9  @author: Stephan Wenger 
 10  @date: 2012-02-29 
 11   
 12  @todo: accept another buffer in constructor, copy _id, proxy shape etc., keep reference to other buffer, disable set_data and __del__ 
 13  """ 
 14   
 15  import numpy as _np 
 16   
 17  import glitter.raw as _gl 
 18  from glitter.utils import primitive_types, buffer_usages, Datatype, coerce_array, ManagedObject, BindableObject 
 19   
 20 -class BaseBuffer(ManagedObject, BindableObject): 
 21      _generate_id = _gl.glGenBuffers 
 22      _delete_id = _gl.glDeleteBuffers 
 23      _db = "buffers" 
 24   
 25      drawmodes = primitive_types 
 26      usages = buffer_usages 
 27   
 28 -    def __init__(self, data=None, shape=None, dtype=None, usage=None, context=None): 
 29          if any(x is NotImplemented for x in (self._target,)): 
 30              raise TypeError("%s is abstract" % self.__class__.__name__) 
 31          super(BaseBuffer, self).__init__(context=context) 
 32          if usage is None: 
 33              usage = BaseBuffer.usages.STATIC_DRAW 
 34          else: 
 35              usage = self.usages(usage) 
 36          self.set_data(data=data, shape=shape, dtype=dtype, usage=usage) 
 37   
 38 -    def set_data(self, data=None, shape=None, dtype=None, usage=None): 
 39          if data is None: 
 40              if shape is None or dtype is None: 
 41                  raise ValueError("must specify either data or both shape and dtype") 
 42              self._shape = shape 
 43              self._dtype = dtype.coerced(force_gl=True) 
 44          else: 
 45              data = coerce_array(data, dtype, force_gl=True) 
 46              if shape is not None: 
 47                  data = data.reshape(shape) 
 48              self._shape = data.shape 
 49              self._dtype = Datatype.from_numpy(data.dtype) 
 50   
 51          if usage is None: 
 52              usage = self.usage 
 53   
 54          _nbytes = _np.prod(self._shape) * self._dtype.nbytes 
 55          _data = data.ctypes if data is not None else _gl.POINTER(_gl.GLvoid)() 
 56          with self: 
 57              _gl.glBufferData(self._target, _nbytes, _data, usage._value) 
 58   
 59 -    def get_data(self): 
 60          _data = _np.empty(self.shape, dtype=self.dtype.as_numpy()) 
 61          with self: 
 62              _gl.glGetBufferSubData(self._target, 0, _data.nbytes, _data.ctypes) 
 63          return _data 
 64   
 65      @property 
 66 -    def data(self): 
 67          return self.get_data() 
 68   
 69      @data.setter 
 70 -    def data(self, data): 
 71          self.set_data(data) 
 72   
 73      @property 
 74 -    def shape(self): 
 75          return self._shape 
 76   
 77 -    def __len__(self): 
 78          return self.shape[0] 
 79   
 80      @property 
 81 -    def dtype(self): 
 82          return self._dtype 
 83   
 84      @property 
 85 -    def _size(self): 
 86          _size = _gl.GLint() 
 87          with self: 
 88              _gl.glGetBufferParameteriv(self._target, _gl.GL_BUFFER_SIZE, _gl.pointer(_size)) 
 89          return _size.value 
 90   
 91      @property 
 92 -    def usage(self): 
 93          _usage = _gl.GLint() 
 94          with self: 
 95              _gl.glGetBufferParameteriv(self._target, _gl.GL_BUFFER_USAGE, _gl.pointer(_usage)) 
 96          return BaseBuffer.usages[_usage.value] 
 97   
 98  __all__ = ["BaseBuffer"] 
 99