我正在为OBJ文件制作一个文件解析器，所有内容都进入了正确的位置，但由于某种原因它直到文件末尾都没有运行。
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
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;
这是前3行所需的代码然后才停止。我正在检查totalFaces向量，该向量包含每组3的第一个数字。
**f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9
f 1/2/3 4//6 7/8/9**
是我的obj文件。
答案 0 :(得分：2)
您不必使用eof（）。看看我的代码：
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);
}
}
在上面的示例代码中，缺少正常的“Vn”。您可以添加另一个条件来检查'Vn'与其他类似。我希望这可以解决你的问题。如果您需要完整的示例程序，请查看here。
答案 1 :(得分：1)
在循环条件中检查eof()是不正确的。这不是预测，它表明之前的读取因EOF而失败。例如。即使是空文件也不会以.eof为真开始。
此外，'vn'既不是一个字符，也不是两个字符。 line[0]绝对是一个字符，显然不能等于两个字符“vn”。