Metaball: Evaluate metaball objects as mesh components

With the ultimate goal of simplifying drawing and evaluation,
this patch makes the following changes and removes code:
- Use `Mesh` instead of `DispList` for evaluated basis metaballs.
- Remove all `DispList` drawing code, which is now unused.
- Simplify code that converts evaluated metaballs to meshes.
- Store the evaluated mesh in the evaluated geometry set.

This has the following indirect benefits:
- Evaluated meshes from metaball objects can be used in geometry nodes.
- Renderers can ignore evaluated metaball objects completely
- Cycles rendering no longer has to convert to mesh from `DispList`.
- We get closer to removing `DispList` completely.
- Optimizations to mesh rendering will also apply to metaball objects.

The vertex normals on the evaluated mesh are technically invalid;
the regular calculation wouldn't reproduce them. Metaball objects
don't support modifiers though, so it shouldn't be a problem.
Eventually we can support per-vertex custom normals (T93551).

Differential Revision: https://developer.blender.org/D14593

1 files changed, 0 insertions, 5 deletions

diff --git a/source/blender/blenkernel/BKE_displist.h b/source/blender/blenkernel/BKE_displist.h
index cdca740555a..6551e732300 100644
--- a/source/blender/blenkernel/BKE_displist.h
+++ b/source/blender/blenkernel/BKE_displist.h
@@ -24,8 +24,6 @@ enum {
   DL_SURF = 2,
   /** Triangles. */
   DL_INDEX3 = 4,
-  /** Quads, with support for triangles (when values of the 3rd and 4th indices match). */
-  DL_INDEX4 = 5,
   // DL_VERTCOL = 6, /* UNUSED */
   /** Isolated points. */
   DL_VERTS = 7,
@@ -62,15 +60,12 @@ typedef struct DispList {
 } DispList;
 
 DispList *BKE_displist_find(struct ListBase *lb, int type);
-void BKE_displist_normals_add(struct ListBase *lb);
-void BKE_displist_count(const struct ListBase *lb, int *totvert, int *totface, int *tottri);
 void BKE_displist_free(struct ListBase *lb);
 
 void BKE_displist_make_curveTypes(struct Depsgraph *depsgraph,
                                   const struct Scene *scene,
                                   struct Object *ob,
                                   bool for_render);
-void BKE_displist_make_mball(struct Depsgraph *depsgraph, struct Scene *scene, struct Object *ob);
 
 void BKE_curve_calc_modifiers_pre(struct Depsgraph *depsgraph,
                                   const struct Scene *scene,