const EdgeIterator &EdgeIterator::operator++()
{
// already at end?
if(isAtEnd())
return *this;
++_edgeIndex;
// at end of primitive?
if(_actPrimIndex >= PrimitiveIterator::getLength() ||
getType() == GL_LINE_STRIP ||
getType() == GL_LINE_LOOP ) // TODO: add GL_POLYLINE here ?!?!
{
++(static_cast<PrimitiveIterator&>(*this));
startPrim();
return *this;
}
switch(getType())
{
case GL_LINES: _edgePntIndex[0] = _actPrimIndex++;
_edgePntIndex[1] = _actPrimIndex++;
break;
#if 0 // probably to be implemented
case GL_POLYGON: TODO
break;
case GL_TRIANGLES: TODO
break;
case GL_QUAD_STRIP: TODO
break;
case GL_TRIANGLE_STRIP: TODO
break;
case GL_TRIANGLE_FAN: TODO
break;
case GL_QUADS: TODO
break;
#endif // probably to be implemented
default: SWARNING << "EdgeIterator::++: encountered "
<< "unknown primitive type "
<< getType()
<< ", ignoring!" << std::endl;
startPrim();
break;
}
return *this;
}
/*! Set the iterator to the beginning of the geometry. Is primarily used by
OSG::Geometry::beginFaces, but can also be used to quickly recycle an
iterator.
*/
void FaceIterator::setToBegin(void)
{
PrimitiveIterator::setToBegin();
_faceIndex = 0;
startPrim();
}
/*! The increment operator steps the iterator to the next face. If it is
already beyond the last face it does not change.
\dev This is the central function of the whole iterator. It changes
_facePntIndex to contain the data for the next face, depending on the type
of the currently active primitive and steps to the next primitive if the
current one is exhausted. The only tricky part is the left/right swap for
triangle strips, the rest is pretty simple. \enddev
*/
void FaceIterator::operator++()
{
// already at end?
if(isAtEnd())
return;
++_faceIndex;
// at end of primitive?
if(_actPrimIndex >= PrimitiveIterator::getLength())
{
++(static_cast<PrimitiveIterator&>(*this));
startPrim();
return;
}
switch(getType())
{
case GL_TRIANGLES: _facePntIndex[0] = _actPrimIndex++;
_facePntIndex[1] = _actPrimIndex++;
_facePntIndex[2] = _actPrimIndex++;
_facePntIndex[3] = -1;
break;
case GL_QUAD_STRIP: _facePntIndex[0] = _facePntIndex[3];
_facePntIndex[1] = _facePntIndex[2];
_facePntIndex[3] = _actPrimIndex++;
_facePntIndex[2] = _actPrimIndex++;
break;
case GL_TRIANGLE_STRIP: if(_actPrimIndex & 1)
{
_facePntIndex[0] = _facePntIndex[2];
}
else
{
_facePntIndex[1] = _facePntIndex[2];
}
_facePntIndex[2] = _actPrimIndex++;
if(getPositionIndex(0) == getPositionIndex(1) ||
getPositionIndex(0) == getPositionIndex(2) ||
getPositionIndex(1) == getPositionIndex(2))
{
--_faceIndex;
++(*this);
}
break;
case GL_POLYGON:
case GL_TRIANGLE_FAN: _facePntIndex[1] = _facePntIndex[2];
_facePntIndex[2] = _actPrimIndex++;
break;
case GL_QUADS: _facePntIndex[0] = _actPrimIndex++;
_facePntIndex[1] = _actPrimIndex++;
_facePntIndex[2] = _actPrimIndex++;
_facePntIndex[3] = _actPrimIndex++;
break;
default: SWARNING << "FaceIterator::++: encountered "
<< "unknown primitive type "
<< getType()
<< ", ignoring!" << std::endl;
startPrim();
break;
}
}
/*! Set the iterator to the beginning of the geometry. Is primarily used by
OSG::Geometry::beginEdges, but can also be used to quickly recycle an
iterator.
*/
void EdgeIterator::setToBegin(void)
{
PrimitiveIterator::setToBegin();
_edgeIndex = 0;
startPrim();
}
