From 05cf8bfb2ef1289b81a06907d540e78d74c5ee48 Mon Sep 17 00:00:00 2001
From: JeffH-BMG <37119778+JeffH-BMG@users.noreply.github.com>
Date: Tue, 6 Mar 2018 13:48:11 -0500
Subject: [PATCH 1/4] Fix import of binary STL files in double-precision builds

When ASSIMP_DOUBLE_PRECISION is used, the STL loader attempts to read 8-byte double vertex and normal values from the STL file. STL files are written using 4-byte floats, however, and the import will read past the end of the buffer, and possibly crash.
---
 code/STLLoader.cpp | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/code/STLLoader.cpp b/code/STLLoader.cpp
index fc326b2c7..863f7affd 100644
--- a/code/STLLoader.cpp
+++ b/code/STLLoader.cpp
@@ -449,26 +449,29 @@ bool STLImporter::LoadBinaryFile()
     aiVector3D *vp = pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
     aiVector3D *vn = pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
 
+    typedef aiVector3t<float> aiVector3F;
+    aiVector3F* theVec;
+    
     for ( unsigned int i = 0; i < pMesh->mNumFaces; ++i ) {
         // NOTE: Blender sometimes writes empty normals ... this is not
         // our fault ... the RemoveInvalidData helper step should fix that
-        ::memcpy( vn, sz, sizeof( aiVector3D ) );
-        sz += sizeof(aiVector3D);
-        *(vn+1) = *vn;
-        *(vn+2) = *vn;
-        vn += 3;
 
-        ::memcpy( vp, sz, sizeof( aiVector3D ) );
-        ++vp;
-        sz += sizeof(aiVector3D);
+        // There's one normal for the face in the STL; use it three times
+        // for vertex normals
+        theVec = (aiVector3F*) sz;
+        *vn++ = *theVec;
+        *vn++ = *theVec;
+        *vn++ = *theVec++;
 
-        ::memcpy( vp, sz, sizeof( aiVector3D ) );
-        ++vp;
-        sz += sizeof(aiVector3D);
+        // vertex 1
+        *vp++ = *theVec++;
 
-        ::memcpy( vp, sz, sizeof( aiVector3D ) );
-        ++vp;
-        sz += sizeof(aiVector3D);
+        // vertex 2
+        *vp++ = *theVec++;
+
+        // vertex 3
+        *vp++ = *theVec;
+        sz += 4 * sizeof aiVector3F;
 
         uint16_t color = *((uint16_t*)sz);
         sz += 2;

From 6fd64b95c32699649e6e392fb05bbf0af01cd685 Mon Sep 17 00:00:00 2001
From: JeffH-BMG <37119778+JeffH-BMG@users.noreply.github.com>
Date: Tue, 6 Mar 2018 15:03:44 -0500
Subject: [PATCH 2/4] Fix compile error

Add parens to use of 'sizeof' operator
---
 code/STLLoader.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/STLLoader.cpp b/code/STLLoader.cpp
index 863f7affd..115e5f816 100644
--- a/code/STLLoader.cpp
+++ b/code/STLLoader.cpp
@@ -471,7 +471,7 @@ bool STLImporter::LoadBinaryFile()
 
         // vertex 3
         *vp++ = *theVec;
-        sz += 4 * sizeof aiVector3F;
+        sz += 4 * sizeof( aiVector3F );
 
         uint16_t color = *((uint16_t*)sz);
         sz += 2;

From 89a4cf94957711117e7c64d483bb1fe42d05f7e9 Mon Sep 17 00:00:00 2001
From: JeffH-BMG <37119778+JeffH-BMG@users.noreply.github.com>
Date: Wed, 7 Mar 2018 17:26:01 -0500
Subject: [PATCH 3/4] Respond to comments

Use memcpy() to read normals and vertices, to mitigate alignment issues, per comments.
---
 code/STLLoader.cpp | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/code/STLLoader.cpp b/code/STLLoader.cpp
index 115e5f816..e01162a30 100644
--- a/code/STLLoader.cpp
+++ b/code/STLLoader.cpp
@@ -451,6 +451,7 @@ bool STLImporter::LoadBinaryFile()
 
     typedef aiVector3t<float> aiVector3F;
     aiVector3F* theVec;
+    aiVector3F theVec3F;
     
     for ( unsigned int i = 0; i < pMesh->mNumFaces; ++i ) {
         // NOTE: Blender sometimes writes empty normals ... this is not
@@ -459,19 +460,32 @@ bool STLImporter::LoadBinaryFile()
         // There's one normal for the face in the STL; use it three times
         // for vertex normals
         theVec = (aiVector3F*) sz;
-        *vn++ = *theVec;
-        *vn++ = *theVec;
-        *vn++ = *theVec++;
+        ::memcpy( &theVec3F, theVec, sizeof(aiVector3F) );
+        vn->x = theVec3F.x; vn->y = theVec3F.y; vn->z = theVec3F.z;
+        *(vn+1) = *vn;
+        *(vn+2) = *vn;
+        ++theVec;
+        vn += 3;
 
         // vertex 1
-        *vp++ = *theVec++;
+        ::memcpy( &theVec3F, theVec, sizeof(aiVector3F) );
+        vp->x = theVec3F.x; vp->y = theVec3F.y; vp->z = theVec3F.z;
+        ++theVec;
+        ++vp;
 
         // vertex 2
-        *vp++ = *theVec++;
+        ::memcpy( &theVec3F, theVec, sizeof(aiVector3F) );
+        vp->x = theVec3F.x; vp->y = theVec3F.y; vp->z = theVec3F.z;
+        ++theVec;
+        ++vp;
 
         // vertex 3
-        *vp++ = *theVec;
-        sz += 4 * sizeof( aiVector3F );
+        ::memcpy( &theVec3F, theVec, sizeof(aiVector3F) );
+        vp->x = theVec3F.x; vp->y = theVec3F.y; vp->z = theVec3F.z;
+        ++theVec;
+        ++vp;
+        
+        sz = theVec;
 
         uint16_t color = *((uint16_t*)sz);
         sz += 2;

From cfd56a43a578f77a1c63a95ed28084a3ae3c4e6e Mon Sep 17 00:00:00 2001
From: JeffH-BMG <37119778+JeffH-BMG@users.noreply.github.com>
Date: Wed, 7 Mar 2018 18:24:38 -0500
Subject: [PATCH 4/4] Fix compile error

Fixed bad cast.
---
 code/STLLoader.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/STLLoader.cpp b/code/STLLoader.cpp
index e01162a30..3a85a5495 100644
--- a/code/STLLoader.cpp
+++ b/code/STLLoader.cpp
@@ -485,7 +485,7 @@ bool STLImporter::LoadBinaryFile()
         ++theVec;
         ++vp;
         
-        sz = theVec;
+        sz = (const unsigned char*) theVec;
 
         uint16_t color = *((uint16_t*)sz);
         sz += 2;