Cleanup: Move lineart_cpu.c to C++

To enable further mesh data structure refactoring-- access to loose
edges in particular.

source/blender/gpencil_modifiers/CMakeLists.txt

@@ -67,7 +67,7 @@ set(SRC
   # Lineart code
   intern/lineart/lineart_chain.c
   intern/lineart/lineart_cpp_bridge.cc
-  intern/lineart/lineart_cpu.c
+  intern/lineart/lineart_cpu.cc
   intern/lineart/lineart_ops.c
   intern/lineart/lineart_shadow.c
   intern/lineart/lineart_util.c

source/blender/gpencil_modifiers/MOD_gpencil_lineart.h

@@ -10,6 +10,10 @@
 
 /* Operator types should be in exposed header. */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void OBJECT_OT_lineart_bake_strokes(struct wmOperatorType *ot);
 void OBJECT_OT_lineart_bake_strokes_all(struct wmOperatorType *ot);
 void OBJECT_OT_lineart_clear(struct wmOperatorType *ot);
@@ -20,3 +24,7 @@ void WM_operatortypes_lineart(void);
 struct LineartCache;
 
 void MOD_lineart_clear_cache(struct LineartCache **lc);
+
+#ifdef __cplusplus
+}
+#endif

source/blender/gpencil_modifiers/intern/lineart/MOD_lineart.h

@@ -14,6 +14,10 @@
 
 #include <math.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct LineartStaticMemPoolNode {
   Link item;
   size_t size;
@@ -74,6 +78,7 @@ typedef enum eLineArtElementNodeFlag {
   LRT_ELEMENT_NO_INTERSECTION = (1 << 2),
   LRT_ELEMENT_INTERSECTION_DATA = (1 << 3),
 } eLineArtElementNodeFlag;
+ENUM_OPERATORS(eLineArtElementNodeFlag, LRT_ELEMENT_INTERSECTION_DATA);
 
 typedef struct LineartElementLinkNode {
   struct LineartElementLinkNode *next, *prev;
@@ -929,3 +934,7 @@ void MOD_lineart_gpencil_generate(LineartCache *cache,
 float MOD_lineart_chain_compute_length(LineartEdgeChain *ec);
 
 void ED_operatortypes_lineart(void);
+
+#ifdef __cplusplus
+}
+#endif

source/blender/gpencil_modifiers/intern/lineart/lineart_intern.h

@@ -17,6 +17,10 @@
 #include <math.h>
 #include <string.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct LineartEdge;
 struct LineartData;
 struct LineartStaticMemPool;
@@ -148,7 +152,7 @@ bool lineart_edge_from_triangle(const struct LineartTriangle *tri,
 LineartBoundingArea *lineart_edge_first_bounding_area(struct LineartData *ld,
                                                       double *fbcoord1,
                                                       double *fbcoord2);
-LineartBoundingArea *lineart_bounding_area_next(struct LineartBoundingArea *_this,
+LineartBoundingArea *lineart_bounding_area_next(struct LineartBoundingArea *self,
                                                 double *fbcoord1,
                                                 double *fbcoord2,
                                                 double x,
@@ -169,10 +173,6 @@ void lineart_add_edge_to_array(struct LineartPendingEdges *pe, struct LineartEdg
 void lineart_finalize_object_edge_array_reserve(struct LineartPendingEdges *pe, int count);
 void lineart_destroy_render_data_keep_init(struct LineartData *ld);
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 void lineart_sort_adjacent_items(struct LineartAdjacentEdge *ai, int length);
 
 #ifdef __cplusplus

source/blender/makesdna/DNA_object_types.h

@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include "BLI_utildefines.h"
+
 #include "DNA_object_enums.h"
 
 #include "DNA_customdata_types.h"
@@ -233,6 +235,7 @@ enum eObjectLineArt_Usage {
   OBJECT_LRT_NO_INTERSECTION = (1 << 4),
   OBJECT_LRT_FORCE_INTERSECTION = (1 << 5),
 };
+ENUM_OPERATORS(eObjectLineArt_Usage, OBJECT_LRT_FORCE_INTERSECTION);
 
 enum eObjectLineArt_Flags {
   OBJECT_LRT_OWN_CREASE = (1 << 0),