1 files changed, 69 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_subdivision.h b/source/blender/draw/intern/draw_subdivision.h
index bd02df6d48b..41d177a644a 100644
--- a/source/blender/draw/intern/draw_subdivision.h
+++ b/source/blender/draw/intern/draw_subdivision.h
@@ -41,6 +41,56 @@ typedef struct DRWPatchMap {
 /** \} */
 
 /* -------------------------------------------------------------------- */
+/** \name DRWSubdivLooseEdge
+ *
+ * This stores information about a subdivided loose edge.
+ * \{ */
+
+typedef struct DRWSubdivLooseEdge {
+  /* The corresponding coarse edge, this is always valid. */
+  int coarse_edge_index;
+  /* Pointers into #DRWSubdivLooseGeom.verts. */
+  int loose_subdiv_v1_index;
+  int loose_subdiv_v2_index;
+} DRWSubdivLooseEdge;
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name DRWSubdivLooseVertex
+ *
+ * This stores information about a subdivided loose vertex, that may or may not come from a loose
+ * edge.
+ * \{ */
+
+typedef struct DRWSubdivLooseVertex {
+  /* The corresponding coarse vertex, or -1 if this vertex is the result
+   * of subdivision. */
+  unsigned int coarse_vertex_index;
+  /* Position and normal of the vertex. */
+  float co[3];
+  float nor[3];
+} DRWSubdivLooseVertex;
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name DRWSubdivLooseGeom
+ *
+ * This stores the subdivided vertices and edges of loose geometry from #MeshExtractLooseGeom.
+ * \{ */
+
+typedef struct DRWSubdivLooseGeom {
+  DRWSubdivLooseEdge *edges;
+  DRWSubdivLooseVertex *verts;
+  int edge_len;
+  int vert_len;
+  int loop_len;
+} DRWSubdivLooseGeom;
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
 /** \name DRWSubdivCache
  *
  * This holds the various buffers used to evaluate and render subdivision through OpenGL.
@@ -69,6 +119,11 @@ typedef struct DRWSubdivCache {
   uint num_subdiv_verts;
   uint num_subdiv_quads;
 
+  /* We only do the subdivision traversal for full faces, however we may have geometries that only
+   * have loose edges (e.g. a custom bone shape). This flag is used to detect those cases, as the
+   * counters above will all be set to zero if we do not have subdivision loops. */
+  bool may_have_loose_geom;
+
   /* Number of polygons in the coarse mesh, notably used to compute a coarse polygon index given a
    * subdivision loop index. */
   int num_coarse_poly;
@@ -113,6 +168,8 @@ typedef struct DRWSubdivCache {
 
   DRWPatchMap gpu_patch_map;
 
+  DRWSubdivLooseGeom loose_geom;
+
   /* UBO to store settings for the various compute shaders. */
   struct GPUUniformBuf *ubo;
 } DRWSubdivCache;
@@ -228,3 +285,15 @@ void draw_subdiv_build_edituv_stretch_angle_buffer(const DRWSubdivCache *cache,
 #ifdef __cplusplus
 }
 #endif
+
+#ifdef __cplusplus
+#  include "BLI_span.hh"
+
+/* Helper to access the loose edges. */
+blender::Span<DRWSubdivLooseEdge> draw_subdiv_cache_get_loose_edges(const DRWSubdivCache *cache);
+
+/* Helper to access only the loose vertices, i.e. not the ones attached to loose edges. To access
+ * loose vertices of loose edges #draw_subdiv_cache_get_loose_edges should be used. */
+blender::Span<DRWSubdivLooseVertex> draw_subdiv_cache_get_loose_verts(const DRWSubdivCache *cache);
+
+#endif