C++ C++；OBJ文件解析器
我正在为OBJ文件做一个文件解析器，所有的东西都放在正确的位置，但由于某种原因，它直到文件结束时才运行C++ C++；OBJ文件解析器,c++,opengl,C++,Opengl,我正在为OBJ文件做一个文件解析器，所有的东西都放在正确的位置，但由于某种原因，它直到文件结束时才运行 void loader::readIn() { //!takes in the all the data and //!puts in string first. std::string line; while(!myFile.eof()) { linetype = unknown;//enum set to uknown
void loader::readIn()
{
//!takes in the all the data and
//!puts in string first.
std::string line;
while(!myFile.eof())
{
linetype = unknown;//enum set to uknown
line.clear(); // clear line
ss.clear(); // clear string stream
std::getline(myFile,line); //intake line , to string line
//found = line.find("v "); //enum to check the line type i,e Face ,vertex
if(line[0] == 'v') //! check to see if the first char is v
{
linetype = vertex;
}
// found = line.find("f ");
if(line[0] == 'f') //! checkl to see if the first char is f
{
linetype = face;
}
// found = line.find("vn ");
if(line[0] == 'vn') //! checkl to see if the first char is vn
{
linetype = vertexNormal;
}
// found = line.find("vt ")
if(line[0] == 'vt') //! checkl to see if the first char is vt
{
linetype = vertexTexture;
}
if(line[0] == ' ' || '#') // if the start of the line is empty or a #
{
line.clear(); //clear line
std::getline(myFile,line); // intake the next line
}
switch(linetype)
{
case vertex: //!stores the verrtex floats in vert.
ss >> vertexFloat[0] >> vertexFloat[1] >> vertexFloat[2];
verts.push_back(new coordinate(vertexFloat[0],vertexFloat[1],vertexFloat[2])); //creates new coord
linetype = unknown;
break;
case face:
int n; // these are the counters for the float arrays
int m;
int b;
n = 0;
m = 0;
b = 0;
int faces[3]; //temperary float array
int faceText[3];
int faceNorm[3];
ss.str(line); //string stream intake line
ss.ignore(1);
while( !ss.eof())
{
ss >> faces[n]; // intake first umber
n++;
if(ss.peek() == '/')
{
ss.ignore(1);
if(ss.peek() != '/')
{
ss >> faceText[m];
m++;
}
}
ss.ignore(1);
ss >> faceNorm[b];
b++;
}
for( int i = 0; i < 3 ; ++i)
{
totalFaces.push_back(faces[i]); // push back all the ints on the correct
faceTexture.push_back(faceText[i]); // vector
faceNormal.push_back(faceNorm[i]);
}
break;
是我的obj文件。在循环条件中检查
eof（）.eofvoid Mesh::LoadObjModel(const char *filename)
{
std::ifstream in(filename, std::ios::in);
if (!in)
{
std::cerr << "Cannot open " << filename << std::endl;
exit(1);
}
std::string line;
while (std::getline(in, line))
{
//check v for vertices
if (line.substr(0,2)=="v "){
std::istringstream v(line.substr(2));
glm::vec3 vert;
double x,y,z;
v>>x;v>>y;v>>z;
vert=glm::vec3(x,y,z);
vertices.push_back(vert);
}
//check for texture co-ordinate
else if(line.substr(0,2)=="vt"){
std::istringstream v(line.substr(3));
glm::vec2 tex;
int U,V;
v>>U;v>>V;
tex=glm::vec2(U,V);
texture.push_back(tex);
}
//check for faces
else if(line.substr(0,2)=="f "){
int a,b,c; //to store mesh index
int A,B,C; //to store texture index
//std::istringstream v;
//v.str(line.substr(2));
const char* chh=line.c_str();
sscanf (chh, "f %i/%i %i/%i %i/%i",&a,&A,&b,&B,&c,&C); //here it read the line start with f and store the corresponding values in the variables
//v>>a;v>>b;v>>c;
a--;b--;c--;
A--;B--;C--;
//std::cout<<a<<b<<c<<A<<B<<C;
faceIndex.push_back(a);textureIndex.push_back(A);
faceIndex.push_back(b);textureIndex.push_back(B);
faceIndex.push_back(c);textureIndex.push_back(C);
}
}
//the mesh data is finally calculated here
for(unsigned int i=0;i<faceIndex.size();i++)
{
glm::vec3 meshData;
glm::vec2 texData;
meshData=glm::vec3(vertices[faceIndex[i]].x,vertices[faceIndex[i]].y,vertices[faceIndex[i]].z);
texData=glm::vec2(texture[textureIndex[i]].x,texture[textureIndex[i]].y);
meshVertices.push_back(meshData);
texCoord.push_back(texData);
}
}
void Mesh:：LoadObjModel（常量字符*文件名）
{
std:：ifstream-in（文件名，std:：ios:：in）；
如果（！in）
{
标准：cerr>y；v>>z；
vert=glm:：vec3（x，y，z）；
顶点。向后推（顶点）；
}
//检查纹理坐标
否则，如果（行substr（0,2）=“vt”）{
std：：istringstream v（第3行）；
glm:：vec2-tex；
INTU，V；
v> >U；v>>v；
tex=glm:：vec2（U，V）；
纹理。推回（tex）；
}
//检查人脸
否则，如果（第行substr（0,2）=“f”）{
int a，b，c；//用于存储网格索引
int A，B，C；//用于存储纹理索引
//std:：istringstream v；
//v、 str（品系substr（2））；
const char*chh=line.c_str（）；
sscanf（chh，“f%i/%i%i/%i%i/%i”、&a、&b、&b、&c、&c）；//在这里，它读取以f开头的行，并将相应的值存储在变量中
//v> >a；v>>b；v>>c；
a-；b-；c-；
A-；B-；C-；
//std:：coutw我可以使用什么替代方法将eof（）读取到文件的末尾。只需尝试读取，然后检查流的结果。如果仍然良好，则读取成功，字符串正常。如果没有，则完成。这很简单。为了使其真正方便，std:：getline（stream，line）
返回您可以直接测试的流-流在仍然正常时转换为true
。您可以使用while（std:：getline（myFile，line））{..此处的代码..}为什么要递减a
，b
，c
，a
，b
和c
@Ask，在obj文件索引中，从1开始，而不是从零开始，这是我递减的方式。
void Mesh::LoadObjModel(const char *filename)
{
std::ifstream in(filename, std::ios::in);
if (!in)
{
std::cerr << "Cannot open " << filename << std::endl;
exit(1);
}
std::string line;
while (std::getline(in, line))
{
//check v for vertices
if (line.substr(0,2)=="v "){
std::istringstream v(line.substr(2));
glm::vec3 vert;
double x,y,z;
v>>x;v>>y;v>>z;
vert=glm::vec3(x,y,z);
vertices.push_back(vert);
}
//check for texture co-ordinate
else if(line.substr(0,2)=="vt"){
std::istringstream v(line.substr(3));
glm::vec2 tex;
int U,V;
v>>U;v>>V;
tex=glm::vec2(U,V);
texture.push_back(tex);
}
//check for faces
else if(line.substr(0,2)=="f "){
int a,b,c; //to store mesh index
int A,B,C; //to store texture index
//std::istringstream v;
//v.str(line.substr(2));
const char* chh=line.c_str();
sscanf (chh, "f %i/%i %i/%i %i/%i",&a,&A,&b,&B,&c,&C); //here it read the line start with f and store the corresponding values in the variables
//v>>a;v>>b;v>>c;
a--;b--;c--;
A--;B--;C--;
//std::cout<<a<<b<<c<<A<<B<<C;
faceIndex.push_back(a);textureIndex.push_back(A);
faceIndex.push_back(b);textureIndex.push_back(B);
faceIndex.push_back(c);textureIndex.push_back(C);
}
}
//the mesh data is finally calculated here
for(unsigned int i=0;i<faceIndex.size();i++)
{
glm::vec3 meshData;
glm::vec2 texData;
meshData=glm::vec3(vertices[faceIndex[i]].x,vertices[faceIndex[i]].y,vertices[faceIndex[i]].z);
texData=glm::vec2(texture[textureIndex[i]].x,texture[textureIndex[i]].y);
meshVertices.push_back(meshData);
texCoord.push_back(texData);
}
}