From f5430f4dd7a15991b7096d55f3ddb2349e6c5eed Mon Sep 17 00:00:00 2001
From: Djalim Simaila <DjalimS.pro@outlook.fr>
Date: Wed, 15 Oct 2025 10:03:25 +0200
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20Mesh3D=20class=20for=20loadin?=
 =?UTF-8?q?g=20OBJ=20files?=
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---
 include/Mesh3D.h    |  19 +++++++
 src/core/Mesh3D.cpp | 123 ++++++++++++++++++++++++++++++++++++++++++++
 src/main.cpp        |   8 ++-
 3 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 include/Mesh3D.h
 create mode 100644 src/core/Mesh3D.cpp

diff --git a/include/Mesh3D.h b/include/Mesh3D.h
new file mode 100644
index 0000000..c3da6a1
--- /dev/null
+++ b/include/Mesh3D.h
@@ -0,0 +1,19 @@
+#ifndef _MESH3D
+#define _MESH3D
+
+#include <vector>
+#include <string>
+
+namespace djalim {
+
+  class Mesh3D {
+    public:
+      // Constructor
+      Mesh3D(const std::string& filepath);
+      std::vector<float> meshVertices;
+      void loadOBJFile(const std::string& filepath);
+  };
+}
+
+#endif // !_MESH3D
+
diff --git a/src/core/Mesh3D.cpp b/src/core/Mesh3D.cpp
new file mode 100644
index 0000000..6544d38
--- /dev/null
+++ b/src/core/Mesh3D.cpp
@@ -0,0 +1,123 @@
+#include "Mesh3D.h"
+#include <iostream>
+#include <fstream>
+#include <iterator>
+#include <sstream>
+#include <string>
+#include <vector>
+
+
+struct objVertex {
+  float x, y, z;
+};
+
+struct objVertexTexture{
+  float u,v;
+};
+
+struct objFaceIndice{
+  int v,vt,vn;
+};
+
+struct objFace {
+  objFaceIndice vertices[3];
+};
+
+
+
+djalim::Mesh3D::Mesh3D(const std::string& filepath) {
+  loadOBJFile(filepath);
+}
+
+
+void djalim::Mesh3D::loadOBJFile(const std::string& filepath){
+
+  std::ifstream file(filepath);
+  if (!file.is_open()) {
+    std::cerr << "Failed to open OBJ file: " << filepath << std::endl;
+    exit(1);
+  }
+  std::string line;
+  std::vector<objVertex> vertices;
+  std::vector<objVertex> vertexNormal;
+  std::vector<objVertexTexture> vertexTexture;
+  std::vector<objFace> faces;
+
+  while (std::getline(file, line)) {
+    std::stringstream ss(line);
+    std::string type;
+    ss >> type;
+
+    if (type == "v"){
+      float x, y, z;
+      ss >> x >> y >> z;
+      //std::cout << "found vertice: (" << x << ", " << y << ", " << z << ")" << std::endl;
+      objVertex v = {x, y, z};
+      vertices.push_back(v);
+    }
+    else if (type == "vn"){
+      float x, y, z;
+      ss >> x >> y >> z;
+      //std::cout << "found normal: (" << x << ", " << y << ", " << z << ")" << std::endl;
+      objVertex v = {x, y, z};
+      vertexNormal.push_back(v); 
+    }
+    else if (type == "vt"){  
+      float u, v;
+      ss >> u >> v;
+      //std::cout << "found texture: (" << u << ", " << v << ")" << std::endl;
+      objVertexTexture vt = {u, v};
+      vertexTexture.push_back(vt);
+    }
+    else if (type == "f"){
+      std::cout << "found face" << std::endl;
+      std::cout << ss.str() << std::endl;
+      objFace face;
+      // TODO Find a more elegant way to do this
+      for (int i = 0; i < 3; i++){
+        int a, b, c;
+        char slash;
+        ss >> a >> slash >> b >> slash >> c; 
+        //std::cout << "vertex " << i << " :(" << a << ", " << b << ", " << c << ")" << std::endl;
+        objFaceIndice f = {a-1, b-1, c-1}; 
+        face.vertices[i] = f; 
+      }
+      faces.push_back(face);
+    }
+  }
+  // Pour chaque face
+  for(int i = 0; i < faces.size() ; i++ ){
+    objFace currentFace = faces[i];
+    // pour chaque vertex de cette face
+    for (int j = 0; j < 3; j++){
+
+      int verticeIndex = currentFace.vertices[j].v;
+
+      if(verticeIndex >= vertices.size()){
+        std::cerr << "Error: Vertex index out of range" << std::endl;
+        exit(1); 
+      }
+
+      objVertex currentVertice = vertices[verticeIndex];
+
+      meshVertices.push_back(currentVertice.x);
+      meshVertices.push_back(currentVertice.y);
+      meshVertices.push_back(currentVertice.z);
+
+      //uv
+
+      int verticeTextureIndex = currentFace.vertices[j].vt;
+
+      if(verticeTextureIndex >= vertexTexture.size()){
+        std::cerr << "Error: Texture index out of range" << std::endl;
+        exit(1); 
+      }
+
+      objVertexTexture currentTexture = vertexTexture[verticeTextureIndex];
+
+      meshVertices.push_back(currentTexture.u);
+      meshVertices.push_back(currentTexture.v);
+    }
+  }
+}
+
diff --git a/src/main.cpp b/src/main.cpp
index a1ec38f..a0f318e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,7 +1,11 @@
+#define DEBUG true
+
 #include "engine.h"
+#include "Mesh3D.h"
 
 int main() {
-  djalim::OpenGlEngine engine = djalim::OpenGlEngine("Mon app", 800, 600);
-  engine.start();
+  //djalim::OpenGlEngine engine = djalim::OpenGlEngine("Mon app", 800, 600);
+  //engine.start();
+  djalim::Mesh3D mesh = djalim::Mesh3D("../assets/models/UTAH_BLEND.obj");
   return 0;
 }