D545: Freestyle Python API: new methods for Stroke and StrokeVertexIterator.

This revision extends the Freestyle Python API to make for style module writing
easier.

- freestyle.types.Stroke: A proper support for reversed() is implemented.  It
works the same with other Python sequence objects (returns an iterator starting
from the end).  This is in effect equivalent to Stroke.stroke_vertices_end().

- freestyle.types.StrokeVertexIterator: An incremented, decremented and reversed
method are added.  The first two methods return a new StrokeVertexIterator
object that has been incremented and decremented, respectively. The reversed
method returns a new StrokeVertexIterator object that will traverse stroke
vertices in the opposite direction.

- freestyle.types.Interface0DIterator: Its constructor now accepts a Stroke
object to create an Interface0DIterator that traverses stroke vertices.  This is
in effect equivalent to Stroke.vertices_begin().  The new API makes stroke
shaders involving function calls much simpler as illustrated below:

  # in the old API
  it = stroke.stroke_vertices_begin()
  for vert in it:
      result = somefunc(Interface0DIterator(it))

  # in the new API
  it = Interface0DIterator(stroke)
  for vert in it:
      result = somefunc(it)


Differential Revision: https://developer.blender.org/D545

Reviewers: kjym3

1 files changed, 12 insertions, 3 deletions

diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
index a339e6653c6..faf99e90111 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
@@ -25,6 +25,7 @@
 #include "BPy_Interface0DIterator.h"
 
 #include "../BPy_Convert.h"
+#include "../BPy_Interface1D.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -70,9 +71,10 @@ static int convert_nested_it(PyObject *obj, void *v)
 static int Interface0DIterator_init(BPy_Interface0DIterator *self, PyObject *args, PyObject *kwds)
 {
 	static const char *kwlist_1[] = {"it", NULL};
-	static const char *kwlist_2[] = {"brother", NULL};
+	static const char *kwlist_2[] = {"inter", NULL};
+	static const char *kwlist_3[] = {"brother", NULL};
 	Interface0DIteratorNested *nested_it;
-	PyObject *brother;
+	PyObject *brother, *inter;
 
 	if (PyArg_ParseTupleAndKeywords(args, kwds, "O&", (char **)kwlist_1, convert_nested_it, &nested_it)) {
 		self->if0D_it = new Interface0DIterator(nested_it->copy());
@@ -80,7 +82,14 @@ static int Interface0DIterator_init(BPy_Interface0DIterator *self, PyObject *arg
 		self->reversed = false;
 	}
 	else if (PyErr_Clear(),
-	         PyArg_ParseTupleAndKeywords(args, kwds, "O!", (char **)kwlist_2, &Interface0DIterator_Type, &brother))
+	         PyArg_ParseTupleAndKeywords(args, kwds, "O!", (char **)kwlist_2, &Interface1D_Type, &inter))
+	{
+		self->if0D_it = new Interface0DIterator(((BPy_Interface1D *)inter)->if1D->verticesBegin());
+		self->at_start = true;
+		self->reversed = false;
+	}
+	else if (PyErr_Clear(),
+	         PyArg_ParseTupleAndKeywords(args, kwds, "O!", (char **)kwlist_3, &Interface0DIterator_Type, &brother))
 	{
 		self->if0D_it = new Interface0DIterator(*(((BPy_Interface0DIterator *)brother)->if0D_it));
 		self->at_start = ((BPy_Interface0DIterator *)brother)->at_start;