Python: Add to_curve method to the object API

This patch adds a to_curve method to the Object ID. This method is
analogous to the to_mesh method. The method can operate on curve and
text objects. For text objects, the text is converted into a 3D Curve ID
and that curve is returned. For curve objects, if apply_modifiers is
true, the spline deform modifiers will be applied and a Curve ID with
the result will be returned, otherwise a copy of the curve will be
returned.

The goal of this addition is to allow the developer to access the splines
of text objects and to get the result of modifier applications which was
otherwise not possible.

Reviewed By: Brecht

Differential Revision: https://developer.blender.org/D10354

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index 8b13db8a012..5f414aa2bdd 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -38,6 +38,7 @@ extern "C" {
 
 struct AnimData;
 struct BoundBox;
+struct Curve;
 struct FluidsimSettings;
 struct GeometrySet;
 struct Ipo;
@@ -186,6 +187,12 @@ typedef struct Object_Runtime {
    */
   struct Mesh *object_as_temp_mesh;
 
+  /**
+   * This is a curve representation of corresponding object.
+   * It created when Python calls `object.to_curve()`.
+   */
+  struct Curve *object_as_temp_curve;
+
   /** Runtime evaluated curve-specific data, not stored in the file. */
   struct CurveCache *curve_cache;
 
@@ -623,7 +630,7 @@ enum {
  */
 #define BA_TRANSFORM_LOCKED_IN_PLACE (1 << 7)
 
-#define BA_TRANSFORM_CHILD (1 << 8)   /* child of a transformed object */
+#define BA_TRANSFORM_CHILD (1 << 8) /* child of a transformed object */
 #define BA_TRANSFORM_PARENT (1 << 13) /* parent of a transformed object */
 
 #define OB_FROMDUPLI (1 << 9)