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                         std::cerr << "Missing normals" << std::endl;
  21                         exit(1);
  22                 }
  23                 if (aiMesh->HasTangentsAndBitangents()) {
  24                         aiVector3D t = aiMesh->mTangents[i];
  25                         tangents.push_back(glm::vec3(t.x, t.y, t.z));
  26                         aiVector3D b = aiMesh->mBitangents[i];
  27                         bitangents.push_back(glm::vec3(b.x, b.y, b.z));
  28                 } else {
  29                         std::cerr << "Missing tangents: make sure blender has UV maps" << std::endl;
  30                         exit(1);
  31                 }
  32                 // check for texture coord set 0
  33                 if (aiMesh->HasTextureCoords(0)) {
  34                         const aiVector3D v = aiMesh->mTextureCoords[0][i];
  35                         texCoords.push_back(glm::vec2(v.x, v.y));
  36                 } else {
  37                         texCoords.push_back(glm::vec2(0));
  38                 }
  39                 materialIndex = aiMesh->mMaterialIndex;
  40         }
  41
  42         std::vector<GLuint> indices;
  43
  44         for (int i = 0; i < aiMesh->mNumFaces; i++) {
  45                 const aiFace &face = aiMesh->mFaces[i];
  46                 if(face.mNumIndices == 3) {
  47                         indices.push_back(face.mIndices[0]);
  48                         indices.push_back(face.mIndices[1]);
  49                         indices.push_back(face.mIndices[2]);
  50                 }
  51         }
  52
  53         numIndices = indices.size();
  54
  55         glGenVertexArrays(1, &vao);
  56         glBindVertexArray(vao);
  57
  58         GLuint vbos[6];
  59         glGenBuffers(6, vbos);
  60         GLuint vertexVbo = vbos[0], normalVbo = vbos[1], texCoordVbo = vbos[2], indicesVbo = vbos[3];
  61         GLuint tangentVbo = vbos[4], bitangentVbo = vbos[5];
  62
  63         GLuint posLoc = glGetAttribLocation(progId, "pos");
  64         glBindBuffer(GL_ARRAY_BUFFER, vertexVbo);
  65         glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
  66         glEnableVertexAttribArray(posLoc);
  67         glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  68
  69         GLuint normalLoc = glGetAttribLocation(progId, "unscaledNormal");
  70         glBindBuffer(GL_ARRAY_BUFFER, normalVbo);
  71         glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(glm::vec3), &normals[0], GL_STATIC_DRAW);
  72         glEnableVertexAttribArray(normalLoc);
  73         glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  74
  75         GLuint texCoordLoc = glGetAttribLocation(progId, "vTexCoord");
  76         glBindBuffer(GL_ARRAY_BUFFER, texCoordVbo);
  77         glBufferData(GL_ARRAY_BUFFER, texCoords.size() * sizeof(glm::vec2), &texCoords[0], GL_STATIC_DRAW);
  78         glEnableVertexAttribArray(texCoordLoc);
  79         glVertexAttribPointer(texCoordLoc, 2, GL_FLOAT, GL_FALSE, 0, 0);
  80
  81         /* GLuint tangentLoc = glGetAttribLocation(progId, "tangent"); */
  82         /* glBindBuffer(GL_ARRAY_BUFFER, tangentVbo); */
  83         /* glBufferData(GL_ARRAY_BUFFER, tangents.size() * sizeof(glm::vec3), &tangents[0], GL_STATIC_DRAW); */
  84         /* glEnableVertexAttribArray(tangentLoc); */
  85         /* glVertexAttribPointer(tangentLoc, 3, GL_FLOAT, GL_FALSE, 0, 0); */
  86
  87         /* GLuint bitangentLoc = glGetAttribLocation(progId, "bitangent"); */
  88         /* glBindBuffer(GL_ARRAY_BUFFER, bitangentVbo); */
  89         /* glBufferData(GL_ARRAY_BUFFER, bitangents.size() * sizeof(glm::vec3), &bitangents[0], GL_STATIC_DRAW); */
  90         /* glEnableVertexAttribArray(bitangentLoc); */
  91         /* glVertexAttribPointer(bitangentLoc, 3, GL_FLOAT, GL_FALSE, 0, 0); */
  92
  93         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indicesVbo);
  94         glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), &indices[0], GL_STATIC_DRAW);
  95 }
  96
  97 Model::Node::Node(const aiNode &node, GLuint progId): ai(node), progId(progId) {
  98         for (int i = 0; i < node.mNumMeshes; i++) {
  99                 meshIndices.push_back(node.mMeshes[i]);
 100         }
 101         for (int i = 0; i < node.mNumChildren; i++) {
 102                 const aiNode *child = node.mChildren[i];
 103                 children.push_back(new Node(*child, progId));
 104         }
 105 }
 106
 107 glm::mat4 aiMatrixToMat4(aiMatrix4x4 from) {
 108         glm::mat4 to;
 109         for (int i = 0; i < 4; i++)
 110                 for (int j = 0; j < 4; j++)
 111                         to[i][j] = from[j][i];
 112         return to;
 113 }
 114
 115 void Model::Node::draw( const std::vector<Mesh> &meshes,
 116                                                 const std::vector<Material> &materials,
 117                                                 const Skybox skybox,
 118                                                 glm::mat4 parentTrans = glm::mat4(1)) const {
 119
 120         GLuint modelLoc = glGetUniformLocation(progId, "model");
 121         glm::mat4 m = parentTrans * aiMatrixToMat4(ai.mTransformation) * model;
 122
 123         for (unsigned int i: meshIndices) {
 124                 const Mesh &mesh = meshes[i];
 125                 glBindVertexArray(mesh.vao);
 126
 127                 Material material = materials[mesh.materialIndex];
 128                 material.bind();
 129
 130                 glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
 131
 132                 glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
 133         }
 134         for (Node *child: children) child->draw(meshes, materials, skybox, m);
 135 }
 136
 137 Model::Model(const std::string &path, Program p, Skybox s): program(p), skybox(s) {
 138         glUseProgram(p.progId);
 139
 140         const aiScene *scene = importer.ReadFile(path,
 141                         aiProcess_Triangulate | aiProcess_CalcTangentSpace | aiProcess_GenNormals);
 142         if (!scene) {
 143                 std::cerr << importer.GetErrorString() << std::endl;
 144                 exit(1);
 145         }
 146
 147         for (int i = 0; i < scene->mNumMeshes; i++) {
 148                 const aiMesh *mesh = scene->mMeshes[i];
 149                 meshes.push_back(Mesh(mesh, p.progId));
 150         }
 151
 152         for (unsigned int i = 0; i < scene->mNumMaterials; i++) {
 153                 const aiMaterial &material = *scene->mMaterials[i];
 154                 materials.push_back(Material(material, p.progId));
 155         }
 156
 157         root = new Node(*(scene->mRootNode), p.progId);
 158 }
 159
 160 void Model::draw() const {
 161         glUseProgram(program.progId);
 162         root->draw(meshes, materials, skybox);
 163         program.validate();
 164 }
 165
 166 Model::Node* Model::find(const std::string &name) {
 167         const aiNode *node = root->ai.FindNode(aiString(name));
 168         Model::Node* res = root->findNode(*node);
 169         return res;
 170 }
 171
 172 Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 173         if (&ai == &aiNode) return this;
 174         for (Model::Node *child: children) {
 175                 Model::Node *res = child->findNode(aiNode);
 176                 if (res) return res;
 177         }
 178         return nullptr;
 179 }