Fix T88859: Assert when changing view modes

The `loose_lines`' ibo was not being initialized.

3 files changed, 43 insertions, 20 deletions

diff --git a/source/blender/draw/intern/draw_cache_extract_mesh.cc b/source/blender/draw/intern/draw_cache_extract_mesh.cc
index b48ee1ddc3f..fca40206659 100644
--- a/source/blender/draw/intern/draw_cache_extract_mesh.cc
+++ b/source/blender/draw/intern/draw_cache_extract_mesh.cc
@@ -777,7 +777,6 @@ static void mesh_buffer_cache_create_requested(struct TaskGraph *task_graph,
    *                                               +-----> | extract_task2_loop_3 |
    *                                                       +----------------------+
    */
-  const bool do_lines_loose_subbuffer = mbc->ibo.lines_loose != nullptr;
   const bool do_hq_normals = (scene->r.perf_flag & SCE_PERF_HQ_NORMALS) != 0 ||
                              GPU_use_hq_normals_workaround();
 
@@ -787,8 +786,7 @@ static void mesh_buffer_cache_create_requested(struct TaskGraph *task_graph,
 #define EXTRACT_ADD_REQUESTED(type, type_lowercase, name) \
   do { \
     if (DRW_##type_lowercase##_requested(mbc->type_lowercase.name)) { \
-      const MeshExtract *extractor = mesh_extract_override_get( \
-          &extract_##name, do_hq_normals, do_lines_loose_subbuffer); \
+      const MeshExtract *extractor = mesh_extract_override_get(&extract_##name, do_hq_normals); \
       extractors.append(extractor); \
     } \
   } while (0)
@@ -818,7 +816,22 @@ static void mesh_buffer_cache_create_requested(struct TaskGraph *task_graph,
   EXTRACT_ADD_REQUESTED(VBO, vbo, skin_roots);
 
   EXTRACT_ADD_REQUESTED(IBO, ibo, tris);
-  EXTRACT_ADD_REQUESTED(IBO, ibo, lines);
+  if (DRW_ibo_requested(mbc->ibo.lines)) {
+    const MeshExtract *extractor;
+    if (mbc->ibo.lines_loose != nullptr) {
+      /* Update #lines_loose ibo. */
+      extractor = &extract_lines_with_lines_loose;
+    }
+    else {
+      extractor = &extract_lines;
+    }
+    extractors.append(extractor);
+  }
+  else if (DRW_ibo_requested(mbc->ibo.lines_loose)) {
+    /* Note: #ibo.lines must have been created first. */
+    const MeshExtract *extractor = &extract_lines_loose_only;
+    extractors.append(extractor);
+  }
   EXTRACT_ADD_REQUESTED(IBO, ibo, points);
   EXTRACT_ADD_REQUESTED(IBO, ibo, fdots);
   EXTRACT_ADD_REQUESTED(IBO, ibo, lines_paint_mask);
diff --git a/source/blender/draw/intern/draw_cache_extract_mesh_extractors.c b/source/blender/draw/intern/draw_cache_extract_mesh_extractors.c
index a806632c18d..0a3945291bb 100644
--- a/source/blender/draw/intern/draw_cache_extract_mesh_extractors.c
+++ b/source/blender/draw/intern/draw_cache_extract_mesh_extractors.c
@@ -94,24 +94,12 @@ static const MeshExtract *mesh_extract_override_hq_normals(const MeshExtract *ex
   return extractor;
 }
 
-static const MeshExtract *mesh_extract_override_loose_lines(const MeshExtract *extractor)
-{
-  if (extractor == &extract_lines) {
-    return &extract_lines_with_lines_loose;
-  }
-  return extractor;
-}
-
 const MeshExtract *mesh_extract_override_get(const MeshExtract *extractor,
-                                             const bool do_hq_normals,
-                                             const bool do_lines_loose_subbuffer)
+                                             const bool do_hq_normals)
 {
   if (do_hq_normals) {
     extractor = mesh_extract_override_hq_normals(extractor);
   }
-  if (do_lines_loose_subbuffer) {
-    extractor = mesh_extract_override_loose_lines(extractor);
-  }
   return extractor;
 }
 
@@ -386,7 +374,7 @@ const MeshExtract extract_lines = {
 /** \} */
 
 /* ---------------------------------------------------------------------- */
-/** \name Extract Loose Edges Sub Buffer
+/** \name Extract Lines and Loose Edges Sub Buffer
  * \{ */
 
 static void extract_lines_loose_subbuffer(const MeshRenderData *mr, struct MeshBatchCache *cache)
@@ -425,6 +413,28 @@ const MeshExtract extract_lines_with_lines_loose = {
 /** \} */
 
 /* ---------------------------------------------------------------------- */
+/** \name Extract Loose Edges Sub Buffer
+ * \{ */
+
+static void *extract_lines_loose_only_init(const MeshRenderData *mr,
+                                           struct MeshBatchCache *cache,
+                                           void *buf)
+{
+  BLI_assert(buf == cache->final.ibo.lines_loose);
+  UNUSED_VARS_NDEBUG(buf);
+  extract_lines_loose_subbuffer(mr, cache);
+  return NULL;
+}
+
+const MeshExtract extract_lines_loose_only = {
+    .init = extract_lines_loose_only_init,
+    .data_type = 0,
+    .use_threading = false,
+    .mesh_buffer_offset = offsetof(MeshBufferCache, ibo.lines_loose)};
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
 /** \name Extract Point Indices
  * \{ */
 
diff --git a/source/blender/draw/intern/draw_cache_extract_mesh_private.h b/source/blender/draw/intern/draw_cache_extract_mesh_private.h
index 644354989d8..6761282fe79 100644
--- a/source/blender/draw/intern/draw_cache_extract_mesh_private.h
+++ b/source/blender/draw/intern/draw_cache_extract_mesh_private.h
@@ -463,8 +463,7 @@ void mesh_render_data_update_looptris(MeshRenderData *mr,
 void *mesh_extract_buffer_get(const MeshExtract *extractor, MeshBufferCache *mbc);
 eMRIterType mesh_extract_iter_type(const MeshExtract *ext);
 const MeshExtract *mesh_extract_override_get(const MeshExtract *extractor,
-                                             const bool do_hq_normals,
-                                             const bool do_lines_loose_subbuffer);
+                                             const bool do_hq_normals);
 /*
  * Total number of extractions types.
  */
@@ -473,6 +472,7 @@ const MeshExtract *mesh_extract_override_get(const MeshExtract *extractor,
 extern const MeshExtract extract_tris;
 extern const MeshExtract extract_lines;
 extern const MeshExtract extract_lines_with_lines_loose;
+extern const MeshExtract extract_lines_loose_only;
 extern const MeshExtract extract_points;
 extern const MeshExtract extract_fdots;
 extern const MeshExtract extract_lines_paint_mask;