model.cpp

   1 #include "model.hpp"
   2 #include <iostream>
   3 #include <assimp/postprocess.h>
   4 #include <glm/gtc/type_ptr.hpp>
   5
   6 Model::Mesh::Mesh(const aiMesh *aiMesh, GLuint progId) {
   7
   8         std::vector<glm::vec3> vertices, normals, tangents, bitangents;
   9         std::vector<glm::vec2> texCoords;
  10
  11         for (int i = 0; i < aiMesh->mNumVertices; i++) {
  12                 if (aiMesh->HasPositions()) {
  13                         aiVector3D v = aiMesh->mVertices[i];
  14                         vertices.push_back(glm::vec3(v.x, v.y, v.z));
  15                 }
  16                 if (aiMesh->HasNormals()) {
  17                         aiVector3D v = aiMesh->mNormals[i];
  18                         normals.push_back(glm::vec3(v.x, v.y, v.z));
  19                 } else {
  20                         normals.push_back(glm::vec3(0));
  21                 }
  22                 if (aiMesh->HasTangentsAndBitangents()) {
  23                         aiVector3D t = aiMesh->mTangents[i];
  24                         tangents.push_back(glm::vec3(t.x, t.y, t.z));
  25                         aiVector3D b = aiMesh->mBitangents[i];
  26                         bitangents.push_back(glm::vec3(b.x, b.y, b.z));
  27                 } else {
  28                         tangents.push_back(glm::vec3(0));
  29                         bitangents.push_back(glm::vec3(0));
  30                 }
  31                 // check for texture coord set 0
  32                 if (aiMesh->HasTextureCoords(0)) {
  33                         const aiVector3D v = aiMesh->mTextureCoords[0][i];
  34                         texCoords.push_back(glm::vec2(v.x, v.y));
  35                 } else {
  36                         texCoords.push_back(glm::vec2(0));
  37                 }
  38                 materialIndex = aiMesh->mMaterialIndex;
  39         }
  40
  41         std::vector<GLuint> indices;
  42
  43         for (int i = 0; i < aiMesh->mNumFaces; i++) {
  44                 const aiFace &face = aiMesh->mFaces[i];
  45                 if(face.mNumIndices == 3) {
  46                         indices.push_back(face.mIndices[0]);
  47                         indices.push_back(face.mIndices[1]);
  48                         indices.push_back(face.mIndices[2]);
  49                 }
  50         }
  51
  52         numIndices = indices.size();
  53
  54         glGenVertexArrays(1, &vao);
  55         glBindVertexArray(vao);
  56
  57         GLuint vbos[6];
  58         glGenBuffers(6, vbos);
  59         GLuint vertexVbo = vbos[0], normalVbo = vbos[1], texCoordVbo = vbos[2], indicesVbo = vbos[3];
  60         GLuint tangentVbo = vbos[4], bitangentVbo = vbos[5];
  61
  62         GLuint posLoc = glGetAttribLocation(progId, "vPosition");
  63         glBindBuffer(GL_ARRAY_BUFFER, vertexVbo);
  64         glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
  65         glEnableVertexAttribArray(posLoc);
  66         glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  67
  68         GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
  69         glBindBuffer(GL_ARRAY_BUFFER, normalVbo);
  70         glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(glm::vec3), &normals[0], GL_STATIC_DRAW);
  71         glEnableVertexAttribArray(normalLoc);
  72         glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  73
  74         GLuint texCoordLoc = glGetAttribLocation(progId, "vTexCoord");
  75         glBindBuffer(GL_ARRAY_BUFFER, texCoordVbo);
  76         glBufferData(GL_ARRAY_BUFFER, texCoords.size() * sizeof(glm::vec2), &texCoords[0], GL_STATIC_DRAW);
  77         glEnableVertexAttribArray(texCoordLoc);
  78         glVertexAttribPointer(texCoordLoc, 2, GL_FLOAT, GL_FALSE, 0, 0);
  79
  80         GLuint tangentLoc = glGetAttribLocation(progId, "tangent");
  81         glBindBuffer(GL_ARRAY_BUFFER, tangentVbo);
  82         glBufferData(GL_ARRAY_BUFFER, tangents.size() * sizeof(glm::vec3), &tangents[0], GL_STATIC_DRAW);
  83         glEnableVertexAttribArray(tangentLoc);
  84         glVertexAttribPointer(tangentLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  85
  86         GLuint bitangentLoc = glGetAttribLocation(progId, "bitangent");
  87         glBindBuffer(GL_ARRAY_BUFFER, bitangentVbo);
  88         glBufferData(GL_ARRAY_BUFFER, bitangents.size() * sizeof(glm::vec3), &bitangents[0], GL_STATIC_DRAW);
  89         glEnableVertexAttribArray(bitangentLoc);
  90         glVertexAttribPointer(bitangentLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  91
  92         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indicesVbo);
  93         glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), &indices[0], GL_STATIC_DRAW);
  94 };
  95
  96 Model::Node::Node(const aiNode &node, GLuint progId): ai(node), progId(progId) {
  97         for (int i = 0; i < node.mNumMeshes; i++) {
  98                 meshIndices.push_back(node.mMeshes[i]);
  99         }
 100         for (int i = 0; i < node.mNumChildren; i++) {
 101                 const aiNode *child = node.mChildren[i];
 102                 children.push_back(new Node(*child, progId));
 103         }
 104 }
 105
 106 glm::mat4 aiMatrixToMat4(aiMatrix4x4 from) {
 107         glm::mat4 to;
 108         for (int i = 0; i < 4; i++)
 109                 for (int j = 0; j < 4; j++)
 110                         to[i][j] = from[j][i];
 111         return to;
 112 }
 113
 114 void Model::Node::draw( const std::vector<Mesh> &meshes,
 115                                                 const std::vector<Material> &materials,
 116                                                 glm::mat4 parentTrans = glm::mat4(1)) const {
 117
 118         GLuint modelLoc = glGetUniformLocation(progId, "model");
 119         glm::mat4 m = parentTrans * aiMatrixToMat4(ai.mTransformation) * model;
 120
 121         for (unsigned int i: meshIndices) {
 122                 const Mesh &mesh = meshes[i];
 123                 glBindVertexArray(mesh.vao);
 124
 125                 Material material = materials[mesh.materialIndex];
 126                 material.bind();
 127
 128                 glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
 129
 130                 glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
 131         }
 132         for (Node *child: children) child->draw(meshes, materials, m);
 133 }
 134
 135 Model::Model(const std::string &path, GLuint progId): progId(progId) {
 136         const aiScene *scene = importer.ReadFile(path,
 137                         aiProcess_Triangulate | aiProcess_CalcTangentSpace | aiProcess_GenNormals);
 138         if (!scene) {
 139                 std::cerr << importer.GetErrorString() << std::endl;
 140                 exit(1);
 141         }
 142
 143         for (int i = 0; i < scene->mNumMeshes; i++) {
 144                 const aiMesh *mesh = scene->mMeshes[i];
 145                 meshes.push_back(Mesh(mesh, progId));
 146         }
 147
 148         for (unsigned int i = 0; i < scene->mNumMaterials; i++) {
 149                 const aiMaterial &material = *scene->mMaterials[i];
 150                 materials.push_back(Material(material, progId));
 151         }
 152
 153         root = new Node(*(scene->mRootNode), progId);
 154 }
 155
 156 void Model::draw() const {
 157         root->draw(meshes, materials);
 158 }
 159
 160 Model::Node* Model::find(const std::string &name) {
 161         const aiNode *node = root->ai.FindNode(aiString(name));
 162         Model::Node* res = root->findNode(*node);
 163         return res;
 164 }
 165
 166 Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 167         if (&ai == &aiNode) return this;
 168         for (Model::Node *child: children) {
 169                 Model::Node *res = child->findNode(aiNode);
 170                 if (res) return res;
 171         }
 172         return nullptr;
 173 }