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cc1a6debb1a456d1faf8ccb99857a1f31c209133
vimix/ext/obj/ObjLoader.cpp
brunoherbelin bf953b328a Using vec4 for color (adding alpha)
2020-04-11 22:30:19 +02:00

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//
// ObjLoader.cpp -- modified for glm
// modified from https://github.com/mortennobel/OpenGL_3_2_Utils
//
/*!
* OpenGL 3.2 Utils - Extension to the Angel library (from the book Interactive Computer Graphics 6th ed
* https://github.com/mortennobel/OpenGL_3_2_Utils
*
* New BSD License
*
* Copyright (c) 2011, Morten Nobel-Joergensen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "ObjLoader.h"
#define GLM_ENABLE_EXPERIMENTAL
#include <glm/gtx/string_cast.hpp>
using namespace glm;
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <map>
using namespace std;
const int DEBUG = 1;
void printDebug(vector<vec3> &positions, vector<int> &indices);
void printDebug(Material *m);
vec3 toVec3(istringstream &iss){
float x,y,z;
iss >> x;
iss >> y;
iss >> z;
return vec3(x,y,z);
}
vec2 toVec2(istringstream &iss){
float x,y;
iss >> x;
iss >> y;
return vec2(x,y);
}
struct TriangleIndex{
// this is a vertex, represented as the indices into their
// respective arrays of positions, normals, and texture coords
int position;
int normal;
int uv;
bool replace(std::string& str, const std::string& from, const std::string& to) {
size_t start_pos = str.find(from);
if(start_pos == std::string::npos)
return false;
str.replace(start_pos, from.length(), to);
return true;
}
TriangleIndex(string p):position(-1),normal(-1),uv(-1) {
// position/uv/normal
replace(p, "//","/-1/");
stringstream ss(p);
char buffer[50];
ss.getline(buffer,50, '/');
position = atoi(buffer);
if (ss.good()){
ss.getline(buffer,50, '/');
uv = atoi(buffer);
}
if (ss.good()){
ss.getline(buffer,50, '/');
normal = atoi(buffer);
}
}
// needed to use TriangleIndex as key in map
bool operator <(const TriangleIndex& Rhs) const {
return (position < Rhs.position) ||
(position == Rhs.position && normal < Rhs.normal) ||
(position == Rhs.position && normal == Rhs.normal && uv < Rhs.uv);
}
};
struct TriangleString{
TriangleIndex v0;
TriangleIndex v1;
TriangleIndex v2;
TriangleString(string v0, string v1, string v2):v0(v0),v1(v1),v2(v2){
}
TriangleIndex get(int index){
if (index == 0) {
return v0;
} else if (index == 1) {
return v1;
}
return v2;
}
};
std::string
makeMtlFilename ( std::string mtlfile, std::string objfile )
{
// pull off the path to the directory from the objfile
size_t pos = objfile.rfind ('/');
// tack the directory onto the materal "mtllib" filename
if ( pos == std::string::npos ) {
return mtlfile;
} else {
std::string path;
path = objfile.substr(0,pos);
return path+"/"+mtlfile;
}
}
bool loadMaterialLibrary ( string mtlText, map<string,Material*> &outMaterials)
{
Material *mat = nullptr;
stringstream ifs(mtlText);
char buffer[512];
while (ifs.good()) {
ifs.getline(buffer,512);
string line(buffer);
istringstream iss(line);
string token;
vec3 color;
iss >> token;
if (token.compare("newmtl") ==0) {
// create a new material and store in map
mat = new Material;
iss >> token;
outMaterials[token] = mat;
} else if (token.compare("Ka") == 0 && mat) {
mat->ambient = toVec3 ( iss );
} else if (token.compare("Kd") == 0 && mat) {
mat->diffuse = toVec3 ( iss );
} else if (token.compare("Ks") == 0 && mat) {
mat->specular = toVec3 ( iss );
} else if (token.compare("Ns") == 0 && mat) {
iss >> mat->shininess;
} else if (token.compare("map_Kd") == 0 && mat) {
iss >> mat->diffuseTexture;
} else if (token.compare("map_Disp") == 0 && mat) {
iss >> mat->bumpTexture;
}
}
return (mat != nullptr);
}
bool loadObject(string objText,
vector<vec3> &outPositions,
vector<vec3> &outNormal,
vector<vec2> &outUv,
vector<unsigned int> &outIndices,
std::string &outMtlfilename
)
{
vector<vec3> positions;
vector<vec3> normals;
vector<vec2> uvs;
vector<TriangleString> triangles;
stringstream ifs(objText);
char buffer[512];
while (ifs.good()){
ifs.getline(buffer,512);
string line(buffer);
istringstream iss(line);
string token;
iss >> token;
if (token.compare("o")==0){
// does not support multiple objects
} else if (token.compare("g")==0){
} else if (token.compare("mtllib")==0){
// read the name of .mtl file
iss >> outMtlfilename;
} else if (token.compare("usemtl")==0){
// does not support multiple materials
} else if (token.compare("v")==0){
positions.push_back( toVec3(iss));
} else if (token.compare("vn")==0){
normals.push_back( toVec3(iss));
} else if (token.compare("vt")==0){
uvs.push_back( toVec2(iss));
} else if (token.compare("f")==0){
vector<string> polygon;
do {
string index;
iss >> index;
if (index.length() > 0) {
polygon.push_back(index);
}
} while (iss);
// triangulate polygon (assumes convex )
TriangleString triangle(polygon[0], polygon[1], polygon[2]);
triangles.push_back(triangle);
for (int i=3;i<polygon.size();i++){
TriangleString triangle2(polygon[i-1], polygon[i], polygon[0]);
triangles.push_back(triangle2);
}
}
}
map<TriangleIndex,int> cache;
for (int i=0;i<triangles.size();i++){
TriangleString triangleString = triangles[i];
for (int j=0;j<3;j++){
TriangleIndex index = triangleString.get(j);
map<TriangleIndex,int>::iterator cachedIndex = cache.find(index);
if (cachedIndex != cache.end()) {
outIndices.push_back(cachedIndex->second);
} else {
int vertexIndex = outPositions.size();
outPositions.push_back(positions[index.position-1]);
if (index.normal != -1){
outNormal.push_back(normals[index.normal-1]);
}
if (index.uv != -1) {
outUv.push_back(uvs[index.uv-1]);
}
outIndices.push_back(vertexIndex);
cache[index] = vertexIndex;
}
}
}
return (outPositions.size()>0);
}
struct Group {
vector<TriangleString> triangles;
Material *mat;
};
//
// loadObjectGroups loads a .obj file containing materials and textures,
// creating a ModelNode that draws it.
bool loadObjectGroups ( string filename,
vector<vec3> &outPositions,
vector<vec3> &outNormal,
vector<vec2> &outUv,
vector< vector<unsigned int> > &outIndices, // per group
vector< Material* >&outMaterials // per group
)
{
map<string,Material*> materials;
vector<vec3> positions;
vector<vec3> normals;
vector<vec2> uvs;
map<string,Group*> groups;
string currentGroupName("");
static int groupnum = 1;
string path = std::string( filename );
ifstream ifs ( path.c_str() , ifstream::in );
char buffer[512];
while (ifs.good()){
ifs.getline(buffer,512);
string line(buffer);
istringstream iss(line);
string token;
iss >> token;
if (token.compare("o")==0){
// does not support multiple objects
} else if (token.compare("g")==0){
// for a new group of faces (eg with a diff material)
// create a group
iss >> currentGroupName;
groups[currentGroupName] = new Group;
} else if (token.compare("mtllib")==0){
// read the .mtl file and create the Materials
string mtlfile;
iss >> mtlfile;
// loadMaterialLibrary( mtlfile.c_str(),
// filename,
// materials);
} else if (token.compare("usemtl")==0){
// create group if none exists, or if this is a "usemtl" line without a preceding "g" line
if ( currentGroupName=="" || groups[currentGroupName]->triangles.size() ) {
string name;
ostringstream oss(name);
// static int groupnum = 1;
oss << "dummy" << groupnum++;
currentGroupName=oss.str();
groups[currentGroupName] = new Group;
}
iss >> token;
if (token=="usemtl") {
if (DEBUG)
std::cout << "null token" << std::endl;
token = "dummy1";
}
if (DEBUG) {
std::cout << "group is " << currentGroupName << std::endl;
std::cout << "usemtl " << token << std::endl;
std::cout << "materials[token] == " << materials[token] << std::endl;
}
if ( materials[token] == 0 ) {
materials[token] = new Material;
}
printDebug ( materials[token] );
groups[currentGroupName]->mat = materials[token];
outMaterials.push_back((materials[token]));
} else if (token.compare("v")==0){
positions.push_back( toVec3(iss));
} else if (token.compare("vn")==0){
normals.push_back( toVec3(iss));
} else if (token.compare("vt")==0){
uvs.push_back( toVec2(iss));
} else if (token.compare("f")==0){
// assign face to current group
vector<string> polygon;
do {
string index;
iss >> index;
if (index.length() > 0) {
polygon.push_back(index);
}
} while (iss);
// oops no usemtl or mtllib or group seen
// if ( currentGroupName=="" || groups[currentGroupName]->triangles.size()==0 ) {
if ( currentGroupName=="" ) {
string name;
ostringstream oss(name);
// static int groupnum = 1;
oss << "dummy" << groupnum++;
currentGroupName=oss.str();
groups[currentGroupName] = new Group;
outMaterials.push_back( groups[currentGroupName]->mat = new Material );
}
// triangulate polygon
if ( polygon.size() >= 3 ) {
TriangleString triangle(polygon[0], polygon[1], polygon[2]);
groups[currentGroupName]->triangles.push_back(triangle);
for (int i=3;i<polygon.size();i++){
TriangleString triangle2(polygon[i-1], polygon[i], polygon[0]);
groups[currentGroupName]->triangles.push_back(triangle2);
}
}
}
}
ifs.close();
// XXX
// repeat this for each group.
// return vectors must be made vectors of vectors (or maybe just the indices?)
// for each group
// deref and pack the vertex positions, normal, and uv,
// pack the element array for each group separately
map<TriangleIndex,int> cache;
for ( map<string,Group*>::iterator g = groups.begin(); g != groups.end();g++ ) {
// each group gets its own element array
vector<unsigned int> groupIndices;
for (int i=0;i<g->second->triangles.size();i++){
TriangleString triangleString = g->second->triangles[i];
for (int j=0;j<3;j++){
TriangleIndex index = triangleString.get(j);
map<TriangleIndex,int>::iterator cachedIndex = cache.find(index);
if (cachedIndex != cache.end()) {
groupIndices.push_back(cachedIndex->second);
} else {
int vertexIndex = outPositions.size();
outPositions.push_back(positions[index.position-1]);
if (index.normal != -1){
outNormal.push_back(normals[index.normal-1]);
}
if (index.uv != -1) {
outUv.push_back(uvs[index.uv-1]);
}
groupIndices.push_back(vertexIndex);
cache[index] = vertexIndex;
}
}
}
// pack the indices for this group
outIndices.push_back(groupIndices);
}
//cout <<"Indices "<< outIndices.size() << endl;
//cout <<"Positions "<< outPositions.size() << endl;
//printDebug(outPositions, outIndices);
return true;
}
void printDebug(vector<vec3> &positions, vector<int> &indices){
if (!DEBUG)
return;
for (int i=0;i<indices.size();i++){
// cout << positions[indices[i]] <<" ";
cout << positions[indices[i]].x <<",";
cout << positions[indices[i]].y <<",";
cout << positions[indices[i]].z <<" ";
if ((i+1)%3==0){
cout << endl;
}
}
}
void printDebug(Material *m){
if (!DEBUG) return;
cout << "ambient " << glm::to_string(m->ambient) << endl;
cout << "diffuse " << glm::to_string(m->diffuse) << endl;
cout << "specular " << glm::to_string(m->specular) << endl;
cout << "shininess " << m->shininess << endl;
cout << "diffuse texture " << m->diffuseTexture << endl;
cout << "bump texture " << m->bumpTexture << endl;
}
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