Source Code for Module glitter.contexts.drawbuffers

  1  """Descriptors for per-drawbuffer state. 
  2   
  3  @author: Stephan Wenger 
  4  @date: 2012-02-29 
  5  """ 
  6   
  7  import itertools as _itertools 
  8  import numpy as _np 
  9   
 10  import glitter.raw as _gl 
 11  from glitter.utils import draw_buffers, bool8, GlitterError 
 12   
 13 -class DrawBufferList(object): 
 14 -    def __init__(self, _context): 
 15          self._context = _context 
 16          self._num_buffers = _context.max_draw_buffers 
 17          if not 0 < self._num_buffers < 512: # sanity check 
 18              raise GlitterError("implausible number of draw buffers detected; are you sure there is a current OpenGL context?") 
 19   
 20 -    def __set__(self, obj, value): 
 21          """Set all draw buffers. 
 22   
 23          @param obj: Ignored. 
 24          @type obj: any type 
 25          @param value: The enum of the draw buffer to bind, a number if it is a color attachment. 
 26          @type value: L{draw_buffers} or C{int} 
 27          """ 
 28   
 29          _buffers = (_gl.GLenum * self._num_buffers)() 
 30          for i, o in _itertools.islice(_itertools.izip_longest(range(self._num_buffers), value, fillvalue=None), self._num_buffers): 
 31              _buffers[i] = _gl.GL_NONE if o is None else _gl.GL_COLOR_ATTACHMENT0 + o if isinstance(o, int) else draw_buffers(o)._value 
 32          with self._context: 
 33              _gl.glDrawBuffers(self._num_buffers, _buffers) 
 34   
 35 -    def __getitem__(self, index): 
 36          """Get the draw buffer attached to this target. 
 37           
 38          @param index: Index of the draw buffer to query. 
 39          @type index: C{int} 
 40          @return: The enum of the currently bound draw buffer enum, a number if it is a color attachment. 
 41          @rtype: L{draw_buffers} or C{int} 
 42          """ 
 43   
 44          if not 0 <= index < self._num_buffers: 
 45              raise IndexError 
 46          _buffer = _gl.GLint() 
 47          with self._context: 
 48              _gl.glGetIntegerv(_gl.GL_DRAW_BUFFER0 + index, _buffer) 
 49          attachment = draw_buffers[_buffer.value] 
 50          if attachment.name.startswith("COLOR_ATTACHMENT"): 
 51              return int(attachment.lstrip("COLOR_ATTACHMENT", 1)) 
 52          else: 
 53              return attachment 
 54   
 55 -    def __setitem__(self, index, value): 
 56          """Set a draw buffer. 
 57   
 58          @param index: Index of the draw buffer to set. 
 59          @type index: C{int} 
 60          @param value: The enum of the draw buffer to bind, a number if it is a color attachment. 
 61          @type value: L{draw_buffers} or C{int} 
 62          """ 
 63   
 64          self.__set__(None, [value if i == index else self[i] for i in range(self._num_buffers)]) 
 65   
 66 -    def __delitem__(self, index): 
 67          """Unbind a draw buffer. 
 68   
 69          @param index: Index of the draw buffer to unbind. 
 70          @type index: C{int} 
 71          """ 
 72   
 73          self[index] = None 
 74   
 75 -    def __len__(self): 
 76          return self._num_buffers 
 77   
 78 -    def __str__(self): 
 79          return str(list(self)) 
 80   
 81 -    def __repr__(self): 
 82          return str(self) 
 83   
 84 -class ColorWritemaskList(object): 
 85 -    def __init__(self, _context): 
 86          self._context = _context 
 87          self._num_buffers = _context.max_draw_buffers 
 88          if not 0 < self._num_buffers < 512: # sanity check 
 89              raise GlitterError("implausible number of draw buffers detected; are you sure there is a current OpenGL context?") 
 90   
 91 -    def __set__(self, obj, value): 
 92          if len(value) != self._num_buffers: 
 93              raise ValueError("wrong size") 
 94          for i, v in enumerate(value): 
 95              self[i] = v 
 96   
 97 -    def __getitem__(self, index): 
 98          if not 0 <= index < self._num_buffers: 
 99              raise IndexError 
100          mask = _np.empty(4, bool8.as_numpy()) 
101          with self._context: 
102              _gl.glGetBooleani_v(_gl.GL_COLOR_WRITEMASK, index, _gl.cast(mask.ctypes, _gl.glGetBooleani_v.argtypes[-1])) 
103          return mask 
104   
105 -    def __setitem__(self, index, value): 
106          with self._context: 
107              _gl.glColorMaski(index, *value) 
108   
109 -    def __delitem__(self, index): 
110          self[index] = (True, True, True, True) 
111   
112 -    def __len__(self): 
113          return self._num_buffers 
114   
115 -    def __str__(self): 
116          return str(_np.array(self)) 
117   
118 -    def __repr__(self): 
119          return str(self) 
120