Source Code for Module glitter.framebuffers.framebuffer

  1  """Framebuffer object class. 
  2   
  3  @warn: Framebuffers are currently bound for drawing only (C{GL_DRAW_FRAMEBUFFER}, not C{GL_READ_FRAMEBUFFER}). 
  4  @todo: Implement binding for reading; wrap C{glReadPixels}, C{glBlitFramebuffer}, C{glCopyTexSubImage} and related framebuffer copy functions. 
  5  @todo: Add properties for C{viewport}, C{color_writemask}, C{depth_writemask}, 
  6  C{blend_func}, C{blend_equation}, and C{depth_range} (using 
  7  C{glDepthRangeArray} and C{glDepthRangeIndexed}). 
  8   
  9  @author: Stephan Wenger 
 10  @date: 2012-02-29 
 11  """ 
 12   
 13  import glitter.raw as _gl 
 14  from glitter.utils import ManagedObject, BindableObject, framebuffer_status 
 15   
 16 -class Framebuffer(ManagedObject, BindableObject): 
 17      _generate_id = _gl.glGenFramebuffers 
 18      _delete_id = _gl.glDeleteBuffers 
 19      _db = "framebuffers" 
 20      _binding = "draw_framebuffer_binding" 
 21      _target = _gl.GL_DRAW_FRAMEBUFFER 
 22   
 23      framebuffer_status = framebuffer_status 
 24      _initialized = False 
 25   
 26 -    def __init__(self, *attachments, **kwargs): 
 27          """Create a new framebuffer. 
 28   
 29          @param attachments: Textures to bind to color attachments. 
 30          @type attachments: C{list} of L{Texture}s 
 31          @param kwargs: Named arguments. 
 32          @type kwargs: C{dict} 
 33          @keyword context: The context in which to create the framebuffer. 
 34          @type context: L{Context} 
 35          @keyword depth: An optional depth buffer attachment. 
 36          @type depth: L{Texture} 
 37          @keyword stencil: An optional stencil buffer attachment. 
 38          @type stencil: L{Texture} 
 39          """ 
 40   
 41          super(Framebuffer, self).__init__(context=kwargs.pop("context", None)) 
 42          self._attachments = {} 
 43           
 44          if isinstance(attachments, dict): 
 45              attachments = dict(attachments) 
 46          else: 
 47              attachments = dict(enumerate(attachments)) 
 48          for i in range(self._context.max_color_attachments): 
 49              self[i] = attachments.pop(i, None) 
 50          if attachments: 
 51              raise ValueError("framebuffer has no attachment(s) %s" % ", ".join("'%s'" % x for x in attachments.keys())) 
 52   
 53          self.depth = kwargs.pop("depth", None) 
 54          self.stencil = kwargs.pop("stencil", None) 
 55   
 56          if kwargs: 
 57              raise TypeError("__init__() got an unexpected keyword argument '%s'" % kwargs.keys()[0]) 
 58   
 59          self._initialized = True 
 60   
 61 -    def __getitem__(self, index): 
 62          return self._attachments[index] 
 63   
 64 -    def __setitem__(self, index, value): 
 65          self.attach(index, value) 
 66   
 67 -    def __delitem__(self, index): 
 68          self.attach(index, None) 
 69   
 70 -    def _on_bind(self): 
 71          """Setup global framebuffer related state. 
 72   
 73          @todo: Setup C{color_writemasks}, C{depth_writemasks}, C{blend_funcs}, C{blend_equations}, and C{depth_ranges} after C{viewport}. 
 74          """ 
 75   
 76          if self._initialized: 
 77              self._stack.append(self._context.draw_buffers) 
 78              self._context.draw_buffers = [i if self[i] is not None else None for i in range(self._context.max_color_attachments)] 
 79   
 80              self._stack.append(self._context.viewport) 
 81              if self.shape is not None: 
 82                  self._context.viewport = (0, 0) + self.shape 
 83   
 84 -    def _on_release(self): 
 85          """Restore global framebuffer related state. 
 86   
 87          @todo: Restore C{depth_ranges}, C{blend_equations}, C{blend_funcs}, C{depth_writemasks}, and C{color_writemasks} before C{viewport}. 
 88          """ 
 89   
 90          if self._initialized: 
 91              self._context.viewport = self._stack.pop() 
 92              self._context.draw_buffers = self._stack.pop() 
 93   
 94 -    def _attach(self, attachment, texture=None, layer=None, level=0): 
 95          """Attach a texture to an attachment. 
 96   
 97          C{texture} may be a (texture, layer) tuple generated by 
 98          L{Texture}C{.__getitem__()}. 
 99          """ 
100   
101          if type(texture) is tuple: 
102              if layer is not None: 
103                  raise ValueError("cannot provide layer as both keyword and texture tuple") 
104              texture, layer = texture 
105              return self._attach(attachment, texture, layer, level) 
106   
107          with self: 
108              if texture is None: 
109                  _gl.glFramebufferTextureLayer(self._target, attachment, 0, level, 0) 
110              elif layer is None: 
111                  _gl.glFramebufferTexture(self._target, attachment, texture._id, level) 
112              else: 
113                  _gl.glFramebufferTextureLayer(self._target, attachment, texture._id, level, layer) 
114   
115 -    def attach(self, index, texture=None, layer=None, level=0): 
116          """Attach a texture to color attachment C{index}. 
117   
118          C{texture} may be a (texture, layer) tuple generated by 
119          L{Texture}C{.__getitem__()}.  Otherwise, C{layer} specifies which 
120          texture layer is to be bound. All layers are bound when C{layer} is 
121          C{None}. 
122   
123          C{level} specifies which resolution level of the texture is to be 
124          bound. 
125   
126          If C{texture} is C{None}, the attachment will be unbound. 
127          """ 
128   
129          self._attach(_gl.GL_COLOR_ATTACHMENT0 + index, texture, layer, level) 
130          self._attachments[index] = texture 
131   
132      @property 
133 -    def depth(self): 
134          if not hasattr(self, "_depth"): 
135              return None 
136          return self._depth 
137   
138      @depth.setter 
139 -    def depth(self, depth): 
140          self.attach_depth(depth) 
141   
142      @depth.deleter 
143 -    def depth(self): 
144          self.attach_depth(None) 
145   
146 -    def attach_depth(self, texture=None, layer=None, level=0): 
147          """Attach a texture to the depth attachment. 
148   
149          C{texture} may be a (texture, layer) tuple generated by 
150          L{Texture}C{.__getitem__()}.  Otherwise, C{layer} specifies which 
151          texture layer is to be bound. All layers are bound when C{layer} is 
152          C{None}. 
153   
154          C{level} specifies which resolution level of the texture is to be 
155          bound. 
156   
157          If C{texture} is C{None}, the attachment will be unbound. 
158          """ 
159   
160          self._attach(_gl.GL_DEPTH_ATTACHMENT, texture, layer, level) 
161          self._depth = texture 
162   
163      @property 
164 -    def stencil(self): 
165          if not hasattr(self, "_stencil"): 
166              return None 
167          return self._stencil 
168   
169      @stencil.setter 
170 -    def stencil(self, stencil): 
171          self.attach_stencil(stencil) 
172   
173      @stencil.deleter 
174 -    def stencil(self): 
175          self.attach_stencil(None) 
176   
177 -    def attach_stencil(self, texture=None, layer=None, level=0): 
178          """Attach a texture to the stencil attachment. 
179   
180          C{texture} may be a (texture, layer) tuple generated by 
181          L{Texture}C{.__getitem__()}.  Otherwise, C{layer} specifies which 
182          texture layer is to be bound. All layers are bound when C{layer} is 
183          C{None}. 
184   
185          C{level} specifies which resolution level of the texture is to be 
186          bound. 
187   
188          If C{texture} is C{None}, the attachment will be unbound. 
189          """ 
190   
191          self._attach(_gl.GL_STENCIL_ATTACHMENT, texture, layer, level) 
192          self._stencil = texture 
193   
194      @property 
195 -    def status(self): 
196          """The framebuffer completeness status. 
197   
198          @rtype: L{Framebuffer.framebuffer_status} enum 
199          """ 
200   
201          with self: 
202              return self.framebuffer_status[_gl.glCheckFramebufferStatus(self._target)] 
203   
204      @property 
205 -    def shape(self): 
206          shape = None 
207          for i, attachment in sorted(self._attachments.items()): 
208              if attachment is not None: 
209                  if type(attachment) is tuple: 
210                      texture, layer = attachment 
211                      shape = (min(shape[0], texture.shape[1]), min(shape[1], texture.shape[2])) if shape else texture.shape[1:3] 
212                  else: 
213                      shape = (min(shape[0], attachment.shape[0]), min(shape[1], attachment.shape[1])) if shape else attachment.shape[:2] 
214          if self.depth is not None: 
215              shape = (min(shape[0], self.depth.shape[0]), min(shape[1], self.depth.shape[1])) if shape else self.depth.shape[:2] 
216          if self.stencil is not None: 
217              shape = (min(shape[0], self.stencil.shape[0]), min(shape[1], self.stencil.shape[1])) if shape else self.stencil.shape[:2] 
218          return shape 
219   
220 -    def clear(self, color=None, depth=None, stencil=None): 
221          """Clear the framebuffer. 
222   
223          @param color: Whether to clear the color buffer, and optionally, to which value. 
224          @type color: C{bool} or C{numpy.ndarray}. 
225          @param depth: Whether to clear the depth buffer, and optionally, to which value. 
226          @type depth: C{bool} or C{numpy.ndarray}. 
227          @param stencil: Whether to clear the stencil buffer, and optionally, to which value. 
228          @type stencil: C{bool} or C{numpy.ndarray}. 
229   
230          If no parameters are given, color, depth and stencil are cleared with 
231          the current clear values. 
232   
233          @todo: Use C{glClearBuffer} to clear selected attachments only. 
234          """ 
235   
236          with self: 
237              self._context._perform_gl_clear(color, depth, stencil) 
238   
239  __all__ = ["Framebuffer"] 
240