From 9fa5be20a9d53becf1f364cb5e6e277ecb74b875 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Mon, 26 Dec 2016 10:20:24 +0200
Subject: [PATCH] scn->clear() can't be called from the load callback, because
 it destroys meshes which call glDeleteBuffers. Moved to the
 start of the second-stage scene loader.

---
 src/sceneload.cc |   41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/src/sceneload.cc b/src/sceneload.cc
index 58d1865..1996663 100644
--- a/src/sceneload.cc
+++ b/src/sceneload.cc
@@ -75,6 +75,27 @@ bool Scene::load(const char *fname, unsigned int flags)
 			return false;
 		}
 
+		LoaderData *ldata = new LoaderData;
+		ldata->aiscn = aiscn;
+		ldata->fname = std::string(fname);
+		loader_data = (void*)ldata;
+	}
+
+	/* then, assuming we have successfully loaded everything, proceed to construct
+	 * all the engine objects, which require access to the OpenGL context
+	 */
+	if(flags & SCNLOAD_STAGE_GL) {
+		if(!loader_data) {
+			error_log("second stage scene loader failed to find valid I/O data\n");
+			return false;
+		}
+
+		LoaderData *ldata = (LoaderData*)loader_data;
+		const aiScene *aiscn = ldata->aiscn;
+		fname = ldata->fname.c_str();
+
+		clear();	// clear any previous data (TODO: add flag for not clearing)
+
 		// assimp adds its own root node, which might have transformations
 		Vec3 root_pos, root_scaling(1.0, 1.0, 1.0);
 		Quat root_rot;
@@ -95,25 +116,6 @@ bool Scene::load(const char *fname, unsigned int flags)
 			nodes->set_scaling(root_scaling);
 		}
 
-		LoaderData *ldata = new LoaderData;
-		ldata->aiscn = aiscn;
-		ldata->fname = std::string(fname);
-		loader_data = (void*)ldata;
-	}
-
-	/* then, assuming we have successfully loaded everything, proceed to construct
-	 * all the engine objects, which require access to the OpenGL context
-	 */
-	if(flags & SCNLOAD_STAGE_GL) {
-		if(!loader_data) {
-			error_log("second stage scene loader failed to find valid I/O data\n");
-			return false;
-		}
-
-		LoaderData *ldata = (LoaderData*)loader_data;
-		const aiScene *aiscn = ldata->aiscn;
-		fname = ldata->fname.c_str();
-
 		// load all meshes
 		for(unsigned int i=0; i<aiscn->mNumMeshes; i++) {
 			aiMesh *aimesh = aiscn->mMeshes[i];
@@ -379,7 +381,6 @@ Scene *SceneSet::create_scene()
 
 bool SceneSet::load_scene(Scene *scn, const char *fname)
 {
-	scn->clear();
 	return scn->load(fname, SCNLOAD_FLIPTEX | SCNLOAD_STAGE_IO);
 }
 
-- 
1.7.10.4