1+ #ifndef OPENGLMODEL_H
2+ #define OPENGLMODEL_H
3+
4+ #include < GL\GL.h>
5+ #include < GL\glew.h>
6+
7+ #include < assimp\Importer.hpp> // C++ importer interface
8+ #include < assimp\scene.h> // Output data structure
9+ #include < assimp\postprocess.h> // Post processing flags
10+
11+ #include < glm\glm.hpp>
12+
13+ #include < string>
14+ #include < vector>
15+ #include < memory>
16+ #include < iostream>
17+
18+ using namespace std ;
19+
20+ class Mesh {
21+
22+ public:
23+ Mesh (const aiMesh* mesh) {
24+ load (mesh);
25+ create ();
26+ }
27+
28+ ~Mesh () {
29+ glDeleteBuffers (4 , buffer);
30+ glDeleteVertexArrays (1 , &vao);
31+ }
32+
33+ // dibujar el mesh
34+ void draw () {
35+ glBindVertexArray (vao);
36+ glDrawElements (GL_TRIANGLES, indices.size (), GL_UNSIGNED_INT, NULL );
37+ glBindVertexArray (0 );
38+ };
39+
40+ // inicializar el mesh
41+ void init (const aiMesh* mesh) {
42+ load (mesh);
43+ create ();
44+ };
45+
46+ private:
47+ vector<glm::vec3> vertex;
48+ vector<glm::vec3> normal;
49+ vector<glm::vec2> uv;
50+ vector<unsigned int > indices;
51+
52+ GLuint buffer[4 ];
53+ GLuint vao;
54+
55+ // obtener los datos de cada mesh
56+ void load (const aiMesh* mesh) {
57+
58+ vertex.reserve (mesh->mNumVertices );
59+ uv.reserve (mesh->mNumVertices );
60+ normal.reserve (mesh->mNumVertices );
61+ indices.reserve (3 * mesh->mNumFaces );
62+
63+ for (unsigned int i = 0 ; i < mesh->mNumVertices ; i++) {
64+
65+ // Obtener la posicion de cada vertice
66+ aiVector3D pos = mesh->mVertices [i];
67+ vertex.push_back (glm::vec3 (pos.x , pos.y , pos.z ));
68+
69+ // Obtener las coordenadas de textura
70+ if (mesh->HasTextureCoords (0 )) {
71+ aiVector3D UVW = mesh->mTextureCoords [0 ][i];
72+ uv.push_back (glm::vec2 (UVW.x , UVW.y ));
73+ }
74+
75+ // Obtener los vectores normales
76+ if (mesh->HasNormals ()) {
77+ aiVector3D n = mesh->mNormals [i];
78+ normal.push_back (glm::vec3 (n.x , n.y , n.z ));
79+ }
80+ }
81+
82+ // Obtener los indices
83+ for (unsigned int i = 0 ; i < mesh->mNumFaces ; i++) {
84+ indices.push_back (mesh->mFaces [i].mIndices [0 ]);
85+ indices.push_back (mesh->mFaces [i].mIndices [1 ]);
86+ indices.push_back (mesh->mFaces [i].mIndices [2 ]);
87+ }
88+ }
89+
90+ void create () {
91+ // generar y activar el VAO
92+ glGenVertexArrays (1 , &vao);
93+ glBindVertexArray (vao);
94+
95+ // generar dos ids para los buffer
96+ glGenBuffers (4 , buffer);
97+
98+ // buffer de vertices
99+ glBindBuffer (GL_ARRAY_BUFFER, buffer[0 ]);
100+ glBufferData (GL_ARRAY_BUFFER, vertex.size () * sizeof (glm::vec3), &vertex[0 ], GL_STATIC_DRAW);
101+ glVertexAttribPointer (0 , 3 , GL_FLOAT, GL_FALSE, 0 , NULL );
102+ glEnableVertexAttribArray (0 );
103+
104+ // buffer de textura
105+ if (!uv.empty ()) {
106+ glBindBuffer (GL_ARRAY_BUFFER, buffer[1 ]);
107+ glBufferData (GL_ARRAY_BUFFER, uv.size () * sizeof (glm::vec2), &uv[0 ], GL_STATIC_DRAW);
108+ glVertexAttribPointer (1 , 2 , GL_FLOAT, GL_FALSE, 0 , NULL );
109+ glEnableVertexAttribArray (1 );
110+ }
111+
112+ // buffer de normales
113+ if (!normal.empty ()) {
114+ glBindBuffer (GL_ARRAY_BUFFER, buffer[2 ]);
115+ glBufferData (GL_ARRAY_BUFFER, normal.size () * sizeof (glm::vec3), &normal[0 ], GL_STATIC_DRAW);
116+ glVertexAttribPointer (2 , 3 , GL_FLOAT, GL_FALSE, 0 , NULL );
117+ glEnableVertexAttribArray (2 );
118+ }
119+
120+ // buffer de indices
121+ glBindBuffer (GL_ELEMENT_ARRAY_BUFFER, buffer[3 ]);
122+ glBufferData (GL_ELEMENT_ARRAY_BUFFER, indices.size () * sizeof (unsigned int ), &indices[0 ], GL_STATIC_DRAW);
123+
124+ // desactivar el VAO
125+ glBindVertexArray (0 );
126+ }
127+
128+ };
129+
130+ class Model {
131+
132+ private:
133+ vector<shared_ptr<Mesh>> meshes;
134+
135+ // procesar recusivamente cada nodo de la escena
136+ void processNode (const aiNode* node, const aiScene* scene)
137+ {
138+ // obtener los mesh de esta escena
139+ for (unsigned int i = 0 ; i < node->mNumMeshes ; i++) {
140+ shared_ptr<Mesh> mesh (new Mesh (scene->mMeshes [node->mMeshes [i]]));
141+ meshes.push_back (mesh);
142+ }
143+
144+ // procesar los hijos del nodo
145+ for (unsigned int i = 0 ; i < node->mNumChildren ; i++)
146+ this ->processNode (node->mChildren [i], scene);
147+ }
148+
149+ public:
150+ // cargar el archivo deseado
151+ void init (const std::string& file_name) {
152+ Assimp::Importer importer;
153+ const aiScene* scene = importer.ReadFile (file_name, aiProcess_Triangulate);
154+
155+ if (scene && scene->mRootNode )
156+ processNode (scene->mRootNode , scene);
157+ else cout << importer.GetErrorString () << endl;
158+ }
159+
160+ // dibujar la escena completa
161+ void draw () {
162+ for (auto m : meshes) m->draw ();
163+ }
164+ };
165+
166+ #endif
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