Files
coding-game/src/renderer/wavefront.cpp

376 lines
11 KiB
C++

#include <iostream>
#include <fstream>
#include <sstream>
#include <memory>
#include <filesystem>
#include <GL/glew.h>
#include "renderer/wavefront.h"
ObjElement toElement(const std::string &s) {
if (s == "#") return ObjElement::OHASH;
if (s == "mtllib") return ObjElement::MTLLIB;
if (s == "usemtl") return ObjElement::USEMTL;
if (s == "o") return ObjElement::O;
if (s == "v") return ObjElement::V;
if (s == "vn") return ObjElement::VN;
if (s == "vt") return ObjElement::VT;
if (s == "f") return ObjElement::F;
return ObjElement::OUNKNOWN;
}
MtlElement toMtlElement(const std::string &s) {
if (s == "#") return MtlElement::MHASH;
if (s == "newmtl") return MtlElement::NEWMTL;
if (s == "Ns") return MtlElement::NS;
if (s == "Ka") return MtlElement::KA;
if (s == "Ks") return MtlElement::KS;
if (s == "Kd") return MtlElement::KD;
if (s == "Ni") return MtlElement::NI;
if (s == "d") return MtlElement::D;
if (s == "illum") return MtlElement::ILLUM;
if (s == "map_Kd") return MtlElement::MAP_KD;
if (s == "map_Ka") return MtlElement::MAP_KA;
// if (s == "map_Ke") return MtlElement::MAP_KE;
return MtlElement::MUNKNOWN;
}
void Vertex::DefineAttrib()
{
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_position)));
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_normal)));
glEnableVertexAttribArray(1);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_texCoord)));
glEnableVertexAttribArray(2);
}
inline int Object::NormalizeIndex(const std::string &s, int baseCount) {
if (s.empty()) return -1;
int idx = std::stoi(s);
if (idx > 0) return idx - 1;
return baseCount + idx;
}
Mesh::Mesh() {
glGenVertexArrays(1, &m_vao);
glGenBuffers(1, &m_vbo);
glGenBuffers(1, &m_ebo);
glBindVertexArray(m_vao);
// VBO (vertex buffer)
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferData(GL_ARRAY_BUFFER, 0, nullptr, GL_STATIC_DRAW);
// EBO (index buffer)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, 0, nullptr, GL_STATIC_DRAW);
Vertex::DefineAttrib();
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
Object::Object() {
m_vertices = std::vector<glm::vec3>();
m_normals = std::vector<glm::vec3>();
m_texCoords = std::vector<glm::vec2>();
}
void Object::LoadMaterials(const std::filesystem::path& filename) {
std::ifstream file(filename);
std::string currentMaterialName;
std::shared_ptr<Material> currentMaterial;
std::string line;
while (std::getline(file, line)) {
std::istringstream iss(line);
std::string prefix;
iss >> prefix;
switch(toMtlElement(prefix)) {
case MtlElement::MHASH:
{
std::cout << "comment: " << line << std::endl;
continue;
}
case MtlElement::NEWMTL:
{
if (currentMaterial) {
m_materials.insert(std::make_pair(currentMaterialName, std::move(currentMaterial)));
currentMaterial = nullptr;
}
std::string materialName;
iss >> materialName;
currentMaterialName = materialName;
currentMaterial = std::make_shared<Material>();
break;
}
case MtlElement::NS:
{
float weight;
iss >> weight;
currentMaterial->SetSpecularWeight(weight);
}
case MtlElement::KA:
{
float r, g, b;
iss >> r >> g >> b;
currentMaterial->SetAmbientColor(glm::vec3(r, g, b));
break;
}
case MtlElement::KS:
{
float r, g, b;
iss >> r >> g >> b;
currentMaterial->SetSpecularColor(glm::vec3(r, g, b));
break;
}
case MtlElement::KD:
{
float r, g, b;
iss >> r >> g >> b;
currentMaterial->SetDiffuseColor(glm::vec3(r, g, b));
break;
}
case MtlElement::D:
{
float d;
iss >> d;
currentMaterial->SetOpacity(d);
break;
}
case MtlElement::ILLUM:
{
int illum;
iss >> illum;
currentMaterial->SetIllumination(illum);
break;
}
case MtlElement::MAP_KD:
{
std::string texturePath;
std::string part;
while (iss >> part) {
texturePath += part + " ";
}
texturePath = texturePath.substr(0, texturePath.size() - 1);
currentMaterial->SetDiffuseTexture(Texture::LoadFile(texturePath));
}
}
}
if (currentMaterial) {
// m_materials.insert(std::make_pair(currentMaterialName, std::move(currentMaterial)));
AddMaterial(currentMaterialName, std::move(currentMaterial));
}
}
void Object::AddMaterial(std::string name, std::shared_ptr<Material> material)
{
m_materials.insert(std::make_pair(std::move(name), std::move(material)));
}
std::shared_ptr<Material> Object::GetMaterial(std::string name)
{
auto material = m_materials.find(name);
if (material == m_materials.end()) return nullptr;
return material->second;
}
void Object::CreateNewMesh(const std::string& materialName)
{
Mesh mesh;
mesh.materialName = materialName;
m_meshes.push_back(mesh);
}
Mesh& Object::GetLastMesh()
{
if (m_meshes.empty()) {
auto material = std::make_shared<Material>();
material->SetAmbientColor(glm::vec3(0.52f, 0.52f, 0.52f));
// TODO: come up with name for a default material
AddMaterial("", std::move(material));
CreateNewMesh("");
}
return m_meshes.back();
}
Object Object::LoadFile(const std::string& filename) {
std::ifstream file(filename);
Object obj;
std::string line;
while (std::getline(file, line)) {
std::istringstream iss(line);
std::string prefix;
iss >> prefix;
switch(toElement(prefix)) {
// comment
case ObjElement::OHASH:
{
std::cout << "comment: " << line << std::endl;
continue;
}
case ObjElement::MTLLIB:
{
std::string mtlFile;
iss >> mtlFile;
std::filesystem::path fullPath = filename;
std::filesystem::path mtlPath = fullPath.replace_filename(mtlFile);
obj.LoadMaterials(mtlPath);
std::cout << "loaded mtl at '" << mtlPath << "' with "
<< obj.m_materials.size() << " materials" << std::endl;
break;
}
case ObjElement::USEMTL:
{
std::string materialName;
iss >> materialName;
auto& mesh = obj.GetLastMesh();
if (mesh.materialName != materialName) {
Mesh mesh;
mesh.materialName = materialName;
obj.m_meshes.push_back(mesh);
}
break;
}
// object name I suppose
case ObjElement::O:
{
obj.m_name = line.substr(2);
break;
}
// vertex with its position
case ObjElement::V:
{
float x, y, z, w;
w = 1.0f;
iss >> x >> y >> z;
if (iss >> w) {
x /= w;
y /= w;
z /= w;
}
obj.m_vertices.emplace_back(x, y, z);
break;
}
case ObjElement::VN:
{
float x, y, z;
iss >> x >> y >> z;
obj.m_normals.emplace_back(x, y, z);
break;
}
case ObjElement::VT:
{
float u, v;
iss >> u >> v;
obj.m_texCoords.emplace_back(u, 1.0f - v);
break;
}
case ObjElement::F:
{
auto& mesh = obj.GetLastMesh();
std::string token;
while (iss >> token) {
std::string a, b, c;
std::istringstream ref(token);
std::getline(ref, a, '/');
std::getline(ref, b, '/');
std::getline(ref, c, '/');
int vi = Object::NormalizeIndex(a, (int)obj.m_vertices.size());
int ti = Object::NormalizeIndex(b, (int)obj.m_texCoords.size());
int ni = Object::NormalizeIndex(c, (int)obj.m_normals.size());
glm::vec3 vert, norm;
glm::vec2 texCoord;
vert = obj.m_vertices[vi];
if (ni >= 0) norm = obj.m_normals[ni];
if (ti >= 0) texCoord = obj.m_texCoords[ti];
mesh.m_vertexBuffer.emplace_back(vert, norm, texCoord);
mesh.m_indexBuffer.push_back(mesh.m_vertexBuffer.size() - 1);
}
break;
}
}
}
std::cout << "Object name: " << obj.m_name << std::endl;
std::cout << "Vertices count: " << obj.m_vertices.size() << std::endl;
std::cout << "Normals count: " << obj.m_normals.size() << std::endl;
std::cout << "TexCoords count: " << obj.m_texCoords.size() << std::endl;
std::cout << "Meshes count: " << obj.m_meshes.size() << std::endl;
std::cout << "Materials count: " << obj.m_materials.size() << std::endl;
// std::cout << "Vertex Buffer size: " << obj.m_vertexBuffer.size() << std::endl;
// std::cout << "Index Buffer size: " << obj.m_indexBuffer.size() << std::endl;
file.close();
for (auto &mesh : obj.m_meshes) {
mesh.Upload();
}
return obj;
}
void Object::Render(Shader& shader)
{
for (auto &mesh : m_meshes) {
auto material = GetMaterial(mesh.materialName);
shader.setFloat("ambientStrength", 0.2f);
shader.setFloat("shininess", material->GetSpecularWeight());
shader.setFloat("opacity", material->GetOpacity());
shader.setBool("useSpecular", material->GetIllumination() >= 2);
shader.setFloat("specularStrength", 1.0f);
shader.setVec3("ambientColor", material->GetAmbientColor());
shader.setVec3("diffuseColor", material->GetDiffuseColor());
shader.setVec3("specularColor", material->GetSpecularColor());
if (material->HasDiffuseTexture()) {
shader.setBool("useTexture", true);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, material->GetDiffuseTexture()->GetID());
shader.setInt("diffuseTex", 0);
} else {
shader.setBool("useTexture", false);
}
mesh.Render();
}
}
void Mesh::Upload()
{
glBindVertexArray(m_vao);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferData(GL_ARRAY_BUFFER, m_vertexBuffer.size() * sizeof(Vertex), m_vertexBuffer.data(), GL_STATIC_DRAW);
// Upload indices
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_indexBuffer.size() * sizeof(unsigned int), m_indexBuffer.data(), GL_STATIC_DRAW);
glBindVertexArray(0);
}
void Mesh::Render()
{
Bind();
glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(m_indexBuffer.size()), GL_UNSIGNED_INT, 0);
Unbind();
}