| """Utility module to parse a Feedback buffer""" | |
| from OpenGL import contextdata | |
| from OpenGL.GL.VERSION import GL_1_1 as _simple | |
| def parseFeedback( buffer, entryCount ): | |
| """Parse the feedback buffer into Python object records""" | |
| bufferIndex = 0 | |
| result = [] | |
| getVertex = createGetVertex( ) | |
| while bufferIndex < entryCount: | |
| token = int(buffer[bufferIndex]) | |
| bufferIndex += 1 | |
| if token in SINGLE_VERTEX_TOKENS: | |
| vData, bufferIndex = getVertex( buffer, bufferIndex ) | |
| result.append( (SINGLE_VERTEX_TOKENS.get(token), Vertex(*vData)) ) | |
| elif token in DOUBLE_VERTEX_TOKENS: | |
| vData, bufferIndex = getVertex( buffer, bufferIndex ) | |
| vData2, bufferIndex = getVertex( buffer, bufferIndex ) | |
| result.append( ( | |
| DOUBLE_VERTEX_TOKENS.get(token), | |
| Vertex(*vData), | |
| Vertex(*vData2), | |
| ) ) | |
| elif token == _simple.GL_PASS_THROUGH_TOKEN: | |
| result.append( (_simple.GL_PASS_THROUGH_TOKEN, buffer[bufferIndex])) | |
| bufferIndex += 1 | |
| elif token == _simple.GL_POLYGON_TOKEN: | |
| temp = [_simple.GL_POLYGON_TOKEN] | |
| count = int(buffer[bufferIndex]) | |
| bufferIndex += 1 | |
| for item in range(count): | |
| vData,bufferIndex = getVertex( buffer, bufferIndex ) | |
| temp.append( Vertex(*vData)) | |
| result.append( tuple(temp)) | |
| else: | |
| raise ValueError( | |
| """Unrecognised token %r in feedback stream"""%(token,) | |
| ) | |
| return result | |
| SINGLE_VERTEX_TOKENS = { | |
| _simple.GL_BITMAP_TOKEN: _simple.GL_BITMAP_TOKEN, | |
| _simple.GL_COPY_PIXEL_TOKEN: _simple.GL_COPY_PIXEL_TOKEN, | |
| _simple.GL_DRAW_PIXEL_TOKEN: _simple.GL_DRAW_PIXEL_TOKEN, | |
| _simple.GL_POINT_TOKEN: _simple.GL_POINT_TOKEN, | |
| } | |
| DOUBLE_VERTEX_TOKENS = { | |
| _simple.GL_LINE_TOKEN: _simple.GL_LINE_TOKEN, | |
| _simple.GL_LINE_RESET_TOKEN: _simple.GL_LINE_RESET_TOKEN, | |
| } | |
| class Vertex( object ): | |
| """Simplistic holder for vertex data from a feedback buffer""" | |
| __slots__ = ('vertex','color','texture') | |
| def __init__( self, vertex,color=None,texture=None): | |
| """Store values for access""" | |
| self.vertex = vertex | |
| self.color = color | |
| self.texture = texture | |
| def createGetVertex( ): | |
| mode = contextdata.getValue( "GL_FEEDBACK_BUFFER_TYPE" ) | |
| indexMode = _simple.glGetBooleanv( _simple.GL_INDEX_MODE ) | |
| colorSize = [ 4,1 ][ int(indexMode) ] | |
| if mode in (_simple.GL_2D,_simple.GL_3D): | |
| if mode == _simple.GL_2D: | |
| size = 2 | |
| else: | |
| size = 3 | |
| def getVertex( buffer, bufferIndex ): | |
| end = bufferIndex+size | |
| return (buffer[bufferIndex:end],None,None),end | |
| elif mode == _simple.GL_3D_COLOR: | |
| def getVertex( buffer, bufferIndex ): | |
| end = bufferIndex+3 | |
| colorEnd = end + colorSize | |
| return (buffer[bufferIndex:end],buffer[end:colorEnd],None),colorEnd | |
| else: | |
| if mode == _simple.GL_3D_COLOR_TEXTURE: | |
| size = 3 | |
| else: | |
| size = 4 | |
| def getVertex( buffer, bufferIndex ): | |
| end = bufferIndex+size | |
| colorEnd = end + colorSize | |
| textureEnd = colorEnd + 4 | |
| return (buffer[bufferIndex:end],buffer[end:colorEnd],buffer[colorEnd:textureEnd]),textureEnd | |
| return getVertex | |