Improvements to the Freestyle Python API (needed by the SVG Exporter)

This patch adds some new functionality to the Freestyle Python API, notably:

  - MaterialBP1D, checks whether the supplied arguments have the same material
  - Fixes a potential crash in CurvePoint.fedge (due to NULL pointer)
  - Makes (error handling in) boolean predicates more robust
  - Adds a BoundingBox type, to make working with bounding boxes easier
  - Adds several new functions (get_object_name, get_strokes, is_poly_clockwise, material_from_fedge)
  - Adds a StrokeCollector StrokeShader, that collects all the strokes from a specific call to Operators.create()
  - Adds hashing and rich comparison to the FrsMaterial type

These new features (most of them, anyway) are needed for making a more robust SVG exporter that supports holes in fills.

Reviewers: kjym3, campbellbarton

Subscribers: campbellbarton

Projects: #bf_blender

Differential Revision: https://developer.blender.org/D1245

1 files changed, 4 insertions, 1 deletions

diff --git a/source/blender/freestyle/intern/python/Interface0D/BPy_CurvePoint.cpp b/source/blender/freestyle/intern/python/Interface0D/BPy_CurvePoint.cpp
index 1ef29792d56..9f0660baa9b 100644
--- a/source/blender/freestyle/intern/python/Interface0D/BPy_CurvePoint.cpp
+++ b/source/blender/freestyle/intern/python/Interface0D/BPy_CurvePoint.cpp
@@ -188,7 +188,10 @@ static PyObject *CurvePoint_fedge_get(BPy_CurvePoint *self, void *UNUSED(closure
 {
 	SVertex *A = self->cp->A();
 	Interface0D *B = (Interface0D *)self->cp->B();
-	return Any_BPy_Interface1D_from_Interface1D(*(A->getFEdge(*B)));
+	// B can be NULL under certain circumstances
+	if (B)
+		return Any_BPy_Interface1D_from_Interface1D(*(A->getFEdge(*B)));
+	Py_RETURN_NONE;
 }
 
 PyDoc_STRVAR(CurvePoint_t2d_doc,