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#include "3dobject.hh"
#include <boost/filesystem/fstream.hpp>
#include <stdexcept>
#include <sstream>
#include "texture.hh"
// TODO: test & fix faces that doesn't have texcoords in the file
// TODO: group handling for loader
namespace {
/// Returns a word (delimited by delim) in a string st at position pos (1-based)
std::string getWord(std::string& st, size_t pos, char delim) {
std::istringstream iss(st);
std::string ret;
for (size_t i = 1; i <= pos; i++)
getline(iss, ret, delim);
return ret;
}
}
/// A polygon containing links to required point data
struct Face {
std::vector<int> vertices;
std::vector<int> texcoords;
std::vector<int> normals;
};
/// Load a Wavefront .obj file and possibly scale it also
void Object3d::loadWavefrontObj(fs::path const& filepath, float scale) {
int linenumber = 0;
std::string row;
fs::ifstream file(filepath, std::ios::binary);
if (!file) throw std::runtime_error("Couldn't open object file "+filepath.string());
std::vector<glmath::vec3> vertices;
std::vector<glmath::vec3> normals;
std::vector<glmath::vec2> texcoords;
std::vector<Face> m_faces;
while (getline(file, row)) {
++linenumber;
std::istringstream srow(row);
float x,y,z;
std::string tempst;
if (row.substr(0,2) == "v ") { // Vertices
srow >> tempst >> x >> y >> z;
vertices.push_back(glmath::vec3(x*scale, y*scale, z*scale));
} else if (row.substr(0,2) == "vt") { // Texture Coordinates
srow >> tempst >> x >> y;
texcoords.push_back(glmath::vec2(x, y));
} else if (row.substr(0,2) == "vn") { // Normals
srow >> tempst >> x >> y >> z;
double sum = std::abs(x)+std::abs(y)+std::abs(z);
if (sum == 0) throw std::runtime_error("Invalid normal in "+filepath.string()+":"+std::to_string(linenumber));
x /= sum; y /= sum; z /= sum; // Normalize components
normals.push_back(glmath::vec3(x, y, z));
} else if (row.substr(0,2) == "f ") { // Faces
Face f;
srow >> tempst; // Eat away prefix
// Parse face point's coordinate references
for (std::string fpoint; srow >> fpoint; ) {
for (size_t i = 1; i <= 3; ++i) {
std::string st_id(getWord(fpoint,i,'/'));
if (!st_id.empty()) {
// Vertex indices are 1-based in the file
int v_id = std::stoi(st_id) - 1;
switch (i) {
case 1: f.vertices.push_back(v_id); break;
case 2: f.texcoords.push_back(v_id); break;
case 3: f.normals.push_back(v_id); break;
}
}
}
}
if (!f.vertices.empty() && f.vertices.size() != 3)
throw std::runtime_error("Only triangle faces allowed in "+filepath.string()+":"+std::to_string(linenumber));
// Face must have equal number of v, vt, vn or none of a kind
if (!f.vertices.empty()
&& (f.texcoords.empty() || (f.texcoords.size() == f.vertices.size()))
&& (f.normals.empty() || (f.normals.size() == f.vertices.size()))) {
m_faces.push_back(f);
} else {
throw std::runtime_error("Invalid face in "+filepath.string()+":"+std::to_string(linenumber));
}
}
}
// Construct a vertex array
for (std::vector<Face>::const_iterator i = m_faces.begin(); i != m_faces.end(); ++i) {
bool hasNormals = !i->normals.empty();
bool hasTexCoords = !i->texcoords.empty();
for (size_t j = 0; j < i->vertices.size(); ++j) {
if (hasNormals) m_va.normal(normals[i->normals[j]]);
if (hasTexCoords) m_va.texCoord(texcoords[i->texcoords[j]]);
m_va.vertex(vertices[i->vertices[j]]);
}
}
}
void Object3d::load(fs::path const& filepath, fs::path const& texturepath, float scale) {
if (!texturepath.empty()) m_texture = std::make_unique<Texture>(texturepath);
loadWavefrontObj(filepath, scale);
}
void Object3d::draw() {
UseShader us(getShader("3dobject"));
if (m_texture) {
UseTexture tex(*m_texture);
m_va.draw(GL_TRIANGLES);
} else {
m_va.draw(GL_TRIANGLES);
}
}
void Object3d::draw(float x, float y, float z, float s) {
using namespace glmath;
Transform trans(translate(vec3(x, y, z)) * scale(s)); // Move to position and scale
draw();
}
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