From 7a4d8ec4125d9f5c8e662474ea152b7c2f01fe3e Mon Sep 17 00:00:00 2001
From: ockeymm <88309682+ockeymm@users.noreply.github.com>
Date: Tue, 26 Sep 2023 13:20:13 +0800
Subject: [PATCH] Reduce memory consumption in
 JoinVerticesProcess::ProcessMesh() significantly

---
 code/PostProcessing/JoinVerticesProcess.cpp | 58 ++++++++++-----------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/code/PostProcessing/JoinVerticesProcess.cpp b/code/PostProcessing/JoinVerticesProcess.cpp
index d36915e0c..650336040 100644
--- a/code/PostProcessing/JoinVerticesProcess.cpp
+++ b/code/PostProcessing/JoinVerticesProcess.cpp
@@ -145,7 +145,7 @@ bool areVerticesEqual(
 }
 
 template<class XMesh>
-void updateXMeshVertices(XMesh *pMesh, std::vector<Vertex> &uniqueVertices) {
+void updateXMeshVertices(XMesh *pMesh, std::vector<int> &uniqueVertices) {
     // replace vertex data with the unique data sets
     pMesh->mNumVertices = (unsigned int)uniqueVertices.size();
 
@@ -157,52 +157,52 @@ void updateXMeshVertices(XMesh *pMesh, std::vector<Vertex> &uniqueVertices) {
 
     // Position, if present (check made for aiAnimMesh)
     if (pMesh->mVertices) {
-        delete [] pMesh->mVertices;
+        aiVector3D *oldVertices = pMesh->mVertices;
         pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
-        for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
-            pMesh->mVertices[a] = uniqueVertices[a].position;
-        }
+        for (unsigned int a = 0; a < pMesh->mNumVertices; a++)
+            pMesh->mVertices[a] = oldVertices[uniqueVertices[a]];
+        delete [] oldVertices;
     }
 
     // Normals, if present
     if (pMesh->mNormals) {
-        delete [] pMesh->mNormals;
+        aiVector3D *oldNormals = pMesh->mNormals;
         pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
-        for( unsigned int a = 0; a < pMesh->mNumVertices; a++) {
-            pMesh->mNormals[a] = uniqueVertices[a].normal;
-        }
+        for (unsigned int a = 0; a < pMesh->mNumVertices; a++)
+            pMesh->mNormals[a] = oldNormals[uniqueVertices[a]];
+        delete oldNormals;
     }
     // Tangents, if present
     if (pMesh->mTangents) {
-        delete [] pMesh->mTangents;
+        aiVector3D *oldTangents = pMesh->mTangents;
         pMesh->mTangents = new aiVector3D[pMesh->mNumVertices];
-        for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
-            pMesh->mTangents[a] = uniqueVertices[a].tangent;
-        }
+        for (unsigned int a = 0; a < pMesh->mNumVertices; a++)
+            pMesh->mTangents[a] = oldTangents[uniqueVertices[a]];
+        delete oldTangents;
     }
     // Bitangents as well
     if (pMesh->mBitangents) {
-        delete [] pMesh->mBitangents;
+        aiVector3D *oldBitangents = pMesh->mBitangents;
         pMesh->mBitangents = new aiVector3D[pMesh->mNumVertices];
-        for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
-            pMesh->mBitangents[a] = uniqueVertices[a].bitangent;
-        }
+        for (unsigned int a = 0; a < pMesh->mNumVertices; a++)
+            pMesh->mBitangents[a] = oldBitangents[uniqueVertices[a]];
+        delete oldBitangents;
     }
     // Vertex colors
     for (unsigned int a = 0; pMesh->HasVertexColors(a); a++) {
-        delete [] pMesh->mColors[a];
+        aiColor4D *oldColors = pMesh->mColors[a];
         pMesh->mColors[a] = new aiColor4D[pMesh->mNumVertices];
-        for( unsigned int b = 0; b < pMesh->mNumVertices; b++) {
-            pMesh->mColors[a][b] = uniqueVertices[b].colors[a];
-        }
+        for (unsigned int b = 0; b < pMesh->mNumVertices; b++)
+            pMesh->mColors[a][b] = oldColors[uniqueVertices[b]];
+        delete [] oldColors;
     }
     // Texture coords
     for (unsigned int a = 0; pMesh->HasTextureCoords(a); a++) {
-        delete [] pMesh->mTextureCoords[a];
+        aiVector3D *oldTextureCoords = pMesh->mTextureCoords[a];
         pMesh->mTextureCoords[a] = new aiVector3D[pMesh->mNumVertices];
-        for (unsigned int b = 0; b < pMesh->mNumVertices; b++) {
-            pMesh->mTextureCoords[a][b] = uniqueVertices[b].texcoords[a];
-        }
+        for (unsigned int b = 0; b < pMesh->mNumVertices; b++)
+            pMesh->mTextureCoords[a][b] = oldTextureCoords[uniqueVertices[b]];
+        delete [] oldTextureCoords;
     }
 }
 
@@ -270,7 +270,7 @@ int JoinVerticesProcess::ProcessMesh( aiMesh* pMesh, unsigned int meshIndex) {
     }
 
     // We'll never have more vertices afterwards.
-    std::vector<Vertex> uniqueVertices;
+    std::vector<int> uniqueVertices;
     uniqueVertices.reserve( pMesh->mNumVertices);
 
     // For each vertex the index of the vertex it was replaced by.
@@ -311,7 +311,7 @@ int JoinVerticesProcess::ProcessMesh( aiMesh* pMesh, unsigned int meshIndex) {
     const bool hasAnimMeshes = pMesh->mNumAnimMeshes > 0;
 
     // We'll never have more vertices afterwards.
-    std::vector<std::vector<Vertex>> uniqueAnimatedVertices;
+    std::vector<std::vector<int>> uniqueAnimatedVertices;
     if (hasAnimMeshes) {
         uniqueAnimatedVertices.resize(pMesh->mNumAnimMeshes);
         for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
@@ -345,10 +345,10 @@ int JoinVerticesProcess::ProcessMesh( aiMesh* pMesh, unsigned int meshIndex) {
             //keep track of its index and increment 1
             replaceIndex[a] = newIndex++;
             // add the vertex to the unique vertices
-            uniqueVertices.push_back(v);
+            uniqueVertices.push_back(a);
             if (hasAnimMeshes) {
                 for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
-                    uniqueAnimatedVertices[animMeshIndex].emplace_back(pMesh->mAnimMeshes[animMeshIndex], a);
+                    uniqueAnimatedVertices[animMeshIndex].emplace_back(a);
                 }
             }
         } else{