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