From d893b21f2b6876f3a9902b145bab2bc696908699 Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Sat, 19 Nov 2022 13:12:14 +0100
Subject: [PATCH] assimp: Fix assert loading meshes with multiple primitive
 types

---
 pandatool/src/assimp/assimpLoader.cxx | 46 +++++++++++++++++++--------
 pandatool/src/assimp/assimpLoader.h   | 10 ++++--
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/pandatool/src/assimp/assimpLoader.cxx b/pandatool/src/assimp/assimpLoader.cxx
index 377a59b1c5..7c2691cb0a 100644
--- a/pandatool/src/assimp/assimpLoader.cxx
+++ b/pandatool/src/assimp/assimpLoader.cxx
@@ -215,8 +215,7 @@ build_graph() {
   }
 
   // And then the meshes.
-  _geoms = new PT(Geom)[_scene->mNumMeshes];
-  _geom_matindices = new unsigned int[_scene->mNumMeshes];
+  _geoms = new Geoms[_scene->mNumMeshes];
   for (size_t i = 0; i < _scene->mNumMeshes; ++i) {
     load_mesh(i);
   }
@@ -234,7 +233,6 @@ build_graph() {
   delete[] _textures;
   delete[] _mat_states;
   delete[] _geoms;
-  delete[] _geom_matindices;
 }
 
 /**
@@ -1019,20 +1017,22 @@ load_mesh(size_t index) {
   }
 
   // Create a geom and add the primitives to it.
-  PT(Geom) geom = new Geom(vdata);
+  Geoms &geoms = _geoms[index];
+  geoms._mat_index = mesh.mMaterialIndex;
+
   if (points->get_num_primitives() > 0) {
-    geom->add_primitive(points);
+    geoms._points = new Geom(vdata);
+    geoms._points->add_primitive(points);
   }
   if (lines->get_num_primitives() > 0) {
-    geom->add_primitive(lines);
+    geoms._lines = new Geom(vdata);
+    geoms._lines->add_primitive(lines);
   }
   if (triangles->get_num_primitives() > 0) {
-    geom->add_primitive(triangles);
+    geoms._triangles = new Geom(vdata);
+    geoms._triangles->add_primitive(triangles);
   }
 
-  _geoms[index] = geom;
-  _geom_matindices[index] = mesh.mMaterialIndex;
-
   if (character) {
     _charmap[mesh.mName.C_Str()] = character;
   }
@@ -1138,13 +1138,31 @@ load_node(const aiNode &node, PandaNode *parent) {
     // If there's only mesh, don't bother using a per-geom state.
     if (node.mNumMeshes == 1) {
       meshIndex = node.mMeshes[0];
-      gnode->add_geom(_geoms[meshIndex]);
-      gnode->set_state(_mat_states[_geom_matindices[meshIndex]]);
+      const Geoms &geoms = _geoms[meshIndex];
+      if (geoms._points != nullptr) {
+        gnode->add_geom(geoms._points);
+      }
+      if (geoms._lines != nullptr) {
+        gnode->add_geom(geoms._lines);
+      }
+      if (geoms._triangles != nullptr) {
+        gnode->add_geom(geoms._triangles);
+      }
+      gnode->set_state(_mat_states[geoms._mat_index]);
     } else {
       for (size_t i = 0; i < node.mNumMeshes; ++i) {
         meshIndex = node.mMeshes[i];
-        gnode->add_geom(_geoms[node.mMeshes[i]],
-          _mat_states[_geom_matindices[meshIndex]]);
+        const Geoms &geoms = _geoms[meshIndex];
+        const RenderState *state = _mat_states[geoms._mat_index];
+        if (geoms._points != nullptr) {
+          gnode->add_geom(geoms._points, state);
+        }
+        if (geoms._lines != nullptr) {
+          gnode->add_geom(geoms._lines, state);
+        }
+        if (geoms._triangles != nullptr) {
+          gnode->add_geom(geoms._triangles, state);
+        }
       }
     }
 
diff --git a/pandatool/src/assimp/assimpLoader.h b/pandatool/src/assimp/assimpLoader.h
index 3b4854451d..5e4446f762 100644
--- a/pandatool/src/assimp/assimpLoader.h
+++ b/pandatool/src/assimp/assimpLoader.h
@@ -62,11 +62,17 @@ private:
   Assimp::Importer _importer;
   const aiScene *_scene;
 
+  struct Geoms {
+    PT(Geom) _points;
+    PT(Geom) _lines;
+    PT(Geom) _triangles;
+    unsigned int _mat_index = 0;
+  };
+
   // These arrays are temporarily used during the build_graph run.
   PT(Texture) *_textures;
   CPT(RenderState) *_mat_states;
-  PT(Geom) *_geoms;
-  unsigned int *_geom_matindices;
+  Geoms *_geoms;
   BoneMap _bonemap;
   CharacterMap _charmap;