我有一个 .obj 和 .mtl 文件加载的代码，有断言错误所以我放了一些断言函数，错误是在这部分代码:
assert(!mtlin.is_open(),"2");
if(!mtlin.is_open()) //if not opened error message, clean all memory, return with -1
{
std::cout << "connot open the material file" << std::endl;
clean();
return -1;
}
我试过几个 .mtl 文件，但都给出断言错误! 以下是完整的代码以防万一:
#include <stdlib.h>
#include "glut.h"
#include <GL/gl.h>
#include <GL/glu.h>
#include "objloader.h"
#include <assert.h>
//nothing to explain here
coordinate::coordinate(float a,float b,float c)
{
x=a;
y=b;
z=c;
}
//nothing to explain here
face::face(int facen,int f1,int f2,int f3,int t1,int t2,int t3,int m){
facenum=facen;
faces[0]=f1;
faces[1]=f2;
faces[2]=f3;
texcoord[0]=t1;
texcoord[1]=t2;
texcoord[2]=t3;
mat=m;
four=false;
}
//nothing to explain here
face::face(int facen,int f1,int f2,int f3,int f4,int t1,int t2,int t3,int t4,int m){
facenum=facen;
faces[0]=f1;
faces[1]=f2;
faces[2]=f3;
faces[3]=f4;
texcoord[0]=t1;
texcoord[1]=t2;
texcoord[2]=t3;
texcoord[3]=t4;
mat=m;
four=true;
}
//nothing to explain here
material::material(const char* na,float al,float n,float ni2,float* d,float* a,float* s,int i,int t)
{
name=na;
alpha=al;
ni=ni2;
ns=n;
dif[0]=d[0];
dif[1]=d[1];
dif[2]=d[2];
amb[0]=a[0];
amb[1]=a[1];
amb[2]=a[2];
spec[0]=s[0];
spec[1]=s[1];
spec[2]=s[2];
illum=i;
texture=t;
}
//nothing to explain here
texcoord::texcoord(float a,float b)
{
u=a;
v=b;
}
int objloader::load(const char* filename)
{
std::ifstream in(filename); //open the model file
if(!in.is_open())
{
std::cout << "Nor oepened" << std::endl; //if it's not opened then error message, and return with -1
return -1;
}
char buf[256]; //temp buffer
int curmat=0; //the current (default) material is 0, it's used, when we read the faces
while(!in.eof())
{
in.getline(buf,256); //while we are not in the end of the file, read everything as a string to the coord vector
coord.push_back(new std::string(buf));
}
for(int i=0;i<coord.size();i++) //and then go through all line and decide what kind of line it is
{
if((*coord[i])[0]=='#') //if it's a comment
continue; //we don't have to do anything with it
else if((*coord[i])[0]=='v' && (*coord[i])[1]==' ') //if a vertex
{
float tmpx,tmpy,tmpz;
sscanf(coord[i]->c_str(),"v %f %f %f",&tmpx,&tmpy,&tmpz); //read the 3 floats, which makes up the vertex
vertex.push_back(new coordinate(tmpx,tmpy,tmpz)); //and put it in the vertex vector
}else if((*coord[i])[0]=='v' && (*coord[i])[1]=='n') //if it's a normal vector
{
float tmpx,tmpy,tmpz;
sscanf(coord[i]->c_str(),"vn %f %f %f",&tmpx,&tmpy,&tmpz);
normals.push_back(new coordinate(tmpx,tmpy,tmpz)); //basically do the same
isnormals=true;
}else if((*coord[i])[0]=='f') //if it's a face
{
int a,b,c,d,e;
if(count(coord[i]->begin(),coord[i]->end(),' ')==4) //if this is a quad
{
if(coord[i]->find("//")!=std::string::npos) //if it's contain a normal vector, but not contain texture coorinate
{
sscanf(coord[i]->c_str(),"f %d//%d %d//%d %d//%d %d//%d",&a,&b,&c,&b,&d,&b,&e,&b); //read in this form
faces.push_back(new face(b,a,c,d,e,0,0,0,0,curmat)); //and put to the faces, we don't care about the texture coorinate in this case
//and if there is no material, it doesn't matter, what is curmat
}else if(coord[i]->find("/")!=std::string::npos) //if we have texture coorinate and normal vectors
{
int t[4]; //texture coorinates
//read in this form, and put to the end of the vector
sscanf(coord[i]->c_str(),"f %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d",&a,&t[0],&b,&c,&t[1],&b,&d,&t[2],&b,&e,&t[3],&b);
faces.push_back(new face(b,a,c,d,e,t[0],t[1],t[2],t[3],curmat));
}else{
//else we don't have normal vectors nor texture coorinate
sscanf(coord[i]->c_str(),"f %d %d %d %d",&a,&b,&c,&d);
faces.push_back(new face(-1,a,b,c,d,0,0,0,0,curmat));
}
}else{ //if it's a triangle
//do the same, except we use one less vertex/texture coorinate/face number
if(coord[i]->find("//")!=std::string::npos)
{
sscanf(coord[i]->c_str(),"f %d//%d %d//%d %d//%d",&a,&b,&c,&b,&d,&b);
faces.push_back(new face(b,a,c,d,0,0,0,curmat));
}else if(coord[i]->find("/")!=std::string::npos)
{
int t[3];
sscanf(coord[i]->c_str(),"f %d/%d/%d %d/%d/%d %d/%d/%d",&a,&t[0],&b,&c,&t[1],&b,&d,&t[2],&b);
faces.push_back(new face(b,a,c,d,t[0],t[1],t[2],curmat));
}else{
sscanf(coord[i]->c_str(),"f %d %d %d",&a,&b,&c);
faces.push_back(new face(-1,a,b,c,0,0,0,curmat));
}
}
}else if((*coord[i])[0]=='u' && (*coord[i])[1]=='s' && (*coord[i])[2]=='e') //use material material_name
{
char tmp[200];
sscanf(coord[i]->c_str(),"usemtl %s",tmp); //read the name of the material to tmp
for(int i=0;i<materials.size();i++) //go through all of the materials
{
assert(strcmp(materials[i]->name.c_str(),tmp)==0,"1");
if(strcmp(materials[i]->name.c_str(),tmp)==0) //and compare the tmp with the name of the material
{
curmat=i; //if it's equal then set the current material to that
break;
}
}
}else if((*coord[i])[0]=='m' && (*coord[i])[1]=='t' && (*coord[i])[2]=='l' && (*coord[i])[3]=='l') //material library, a file, which contain
//all of the materials
{
char filen[200];
sscanf(coord[i]->c_str(),"mtllib %s",filen); //read the filename
std::ifstream mtlin(filen); //open the file
assert(!mtlin.is_open(),"2");
if(!mtlin.is_open()) //if not opened error message, clean all memory, return with -1
{
std::cout << "connot open the material file" << std::endl;
clean();
return -1;
}
ismaterial=true; //we use materials
std::vector<std::string> tmp;//contain all of the line of the file
char c[200];
while(!mtlin.eof())
{
mtlin.getline(c,200); //read all lines to tmp
tmp.push_back(c);
}
char name[200]; //name of the material
char filename[200]; //filename of the texture
float amb[3],dif[3],spec[3],alpha,ns,ni; //colors, shininess, and something else
int illum;
unsigned int texture;
bool ismat=false; //do we already have a material read in to these variables?
strcpy(filename,"\0"); //set filename to nullbyte character
for(int i=0;i<tmp.size();i++) //go through all lines of the mtllib file
{
if(tmp[i][0]=='#') //we don't care about comments
continue;
if(tmp[i][0]=='n' && tmp[i][1]=='e' && tmp[i][2]=='w') //new material
{
if(ismat) //if we have a material
{
if(strcmp(filename,"\0")!=0) //if we have a texture
{
materials.push_back(new material(name,alpha,ns,ni,dif,amb,spec,illum,texture)); //push back
strcpy(filename,"\0");
}else{
materials.push_back(new material(name,alpha,ns,ni,dif,amb,spec,illum,-1)); //push back, but use -1 to texture
}
}
ismat=false; //we start from a fresh material
sscanf(tmp[i].c_str(),"newmtl %s",name); //read in the name
}else if(tmp[i][0]=='N' && tmp[i][1]=='s') //the shininess
{
sscanf(tmp[i].c_str(),"Ns %f",&ns);
ismat=true;
}else if(tmp[i][0]=='K' && tmp[i][1]=='a') //the ambient
{
sscanf(tmp[i].c_str(),"Ka %f %f %f",&amb[0],&amb[1],&amb[2]);
ismat=true;
}else if(tmp[i][0]=='K' && tmp[i][1]=='d') //the diffuse
{
sscanf(tmp[i].c_str(),"Kd %f %f %f",&dif[0],&dif[1],&dif[2]);
ismat=true;
}else if(tmp[i][0]=='K' && tmp[i][1]=='s') //the specular
{
sscanf(tmp[i].c_str(),"Ks %f %f %f",&spec[0],&spec[1],&spec[2]);
ismat=true;
}else if(tmp[i][0]=='N' && tmp[i][1]=='i') //the I don't know what is this
{
sscanf(tmp[i].c_str(),"Ni %f",&ni);
ismat=true;
}else if(tmp[i][0]=='d' && tmp[i][1]==' ') //the alpha
{
sscanf(tmp[i].c_str(),"d %f",&alpha);
ismat=true;
}else if(tmp[i][0]=='i' && tmp[i][1]=='l') //the illum (don't ask)
{
sscanf(tmp[i].c_str(),"illum %d",&illum);
ismat=true;
}else if(tmp[i][0]=='m' && tmp[i][1]=='a') //and the texture
{
sscanf(tmp[i].c_str(),"map_Kd %s",filename);
texture=loadTexture(filename); //read the filename, and use the loadTexture function to load it, and get the id.
ismat=true;
}
}
if(ismat) //there is no newmat after the last newmat, so we have to put the last material 'manually'
{
if(strcmp(filename,"\0")!=0)
{
materials.push_back(new material(name,alpha,ns,ni,dif,amb,spec,illum,texture));
}else{
materials.push_back(new material(name,alpha,ns,ni,dif,amb,spec,illum,-1));
}
}
}else if((*coord[i])[0]=='v' && (*coord[i])[1]=='t') //back to the obj file, texture coorinate
{
float u,v;
sscanf(coord[i]->c_str(),"vt %f %f",&u,&v); //read the uv coordinate
texturecoordinate.push_back(new texcoord(u,1-v)); //I push back 1-v instead of normal v, because obj file use the upper left corner as 0,0 coorinate
//but OpenGL use bottom left corner as 0,0, so I convert it
istexture=true;
}
}
if(materials.size()==0) //if some reason the material file doesn't contain any material, we don't have material
ismaterial=false;
else //else we have
ismaterial=true;
std::cout << vertex.size() << " " << normals.size() << " " << faces.size() << " " << materials.size() << std::endl; //test purposes
//draw
int num;
num=glGenLists(1); //I generate a unique identifier for the list
glNewList(num,GL_COMPILE);
int last=-1; //the last material (default -1, which doesn't exist, so we use the first material)
for(int i=0;i<faces.size();i++) //go throught all faces
{
if(last!=faces[i]->mat && ismaterial) //if we have a meterial AND the last material is not the same
{
//set all of the material property
float diffuse[]={materials[faces[i]->mat]->dif[0],materials[faces[i]->mat]->dif[1],materials[faces[i]->mat]->dif[2],1.0};
float ambient[]={materials[faces[i]->mat]->amb[0],materials[faces[i]->mat]->amb[1],materials[faces[i]->mat]->amb[2],1.0};
float specular[]={materials[faces[i]->mat]->spec[0],materials[faces[i]->mat]->spec[1],materials[faces[i]->mat]->spec[2],1.0};
glMaterialfv(GL_FRONT,GL_DIFFUSE,diffuse);
glMaterialfv(GL_FRONT,GL_AMBIENT,ambient);
glMaterialfv(GL_FRONT,GL_SPECULAR,specular);
glMaterialf(GL_FRONT,GL_SHININESS,materials[faces[i]->mat]->ns);
last=faces[i]->mat; //set the current to last
if(materials[faces[i]->mat]->texture==-1) //if we don't have texture, disable it, else enable it
glDisable(GL_TEXTURE_2D);
else{
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,materials[faces[i]->mat]->texture); //and use it
}
}
if(faces[i]->four) //if quad
{
glBegin(GL_QUADS);
if(isnormals) //if there are normals
glNormal3f(normals[faces[i]->facenum-1]->x,normals[faces[i]->facenum-1]->y,normals[faces[i]->facenum-1]->z); //use them
if(istexture && materials[faces[i]->mat]->texture!=-1) //if there are textures
glTexCoord2f(texturecoordinate[faces[i]->texcoord[0]-1]->u,texturecoordinate[faces[i]->texcoord[0]-1]->v); //set the texture coorinate
glVertex3f(vertex[faces[i]->faces[0]-1]->x,vertex[faces[i]->faces[0]-1]->y,vertex[faces[i]->faces[0]-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[1]-1]->u,texturecoordinate[faces[i]->texcoord[1]-1]->v);
glVertex3f(vertex[faces[i]->faces[1]-1]->x,vertex[faces[i]->faces[1]-1]->y,vertex[faces[i]->faces[1]-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[2]-1]->u,texturecoordinate[faces[i]->texcoord[2]-1]->v);
glVertex3f(vertex[faces[i]->faces[2]-1]->x,vertex[faces[i]->faces[2]-1]->y,vertex[faces[i]->faces[2]-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[3]-1]->u,texturecoordinate[faces[i]->texcoord[3]-1]->v);
glVertex3f(vertex[faces[i]->faces[3]-1]->x,vertex[faces[i]->faces[3]-1]->y,vertex[faces[i]->faces[3]-1]->z);
glEnd();
}else{
glBegin(GL_TRIANGLES);
if(isnormals) //if there are normals
glNormal3f(normals[faces[i]->facenum-1]->x,normals[faces[i]->facenum-1]->y,normals[faces[i]->facenum-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[0]-1]->u,texturecoordinate[faces[i]->texcoord[0]-1]->v);
glVertex3f(vertex[faces[i]->faces[0]-1]->x,vertex[faces[i]->faces[0]-1]->y,vertex[faces[i]->faces[0]-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[1]-1]->u,texturecoordinate[faces[i]->texcoord[1]-1]->v);
glVertex3f(vertex[faces[i]->faces[1]-1]->x,vertex[faces[i]->faces[1]-1]->y,vertex[faces[i]->faces[1]-1]->z);
if(istexture && materials[faces[i]->mat]->texture!=-1)
glTexCoord2f(texturecoordinate[faces[i]->texcoord[2]-1]->u,texturecoordinate[faces[i]->texcoord[2]-1]->v);
glVertex3f(vertex[faces[i]->faces[2]-1]->x,vertex[faces[i]->faces[2]-1]->y,vertex[faces[i]->faces[2]-1]->z);
glEnd();
}
}
glEndList();
clean();
lists.push_back(num);
return num;
}
void objloader::clean()
{
//delete all the dynamically allocated memory
for(int i=0;i<coord.size();i++)
delete coord[i];
for(int i=0;i<faces.size();i++)
delete faces[i];
for(int i=0;i<normals.size();i++)
delete normals[i];
for(int i=0;i<vertex.size();i++)
delete vertex[i];
for(int i=0;i<materials.size();i++)
delete materials[i];
for(int i=0;i<texturecoordinate.size();i++)
delete texturecoordinate[i];
//and all elements from the vector
coord.clear();
faces.clear();
normals.clear();
vertex.clear();
materials.clear();
texturecoordinate.clear();
}
objloader::~objloader()
{
//delete lists and textures
for(std::vector<unsigned int>::const_iterator it=texture.begin();it!=texture.end();it++)
{
glDeleteTextures(1,&(*it));
}
for(std::vector<unsigned int>::const_iterator it=lists.begin();it!=lists.end();it++)
{
glDeleteLists(*it,1);
}
}
//load the filename textures (only BMP, R5G6B5 format)
unsigned int objloader::loadTexture(const char* filename)
{
//nothing new in here
unsigned int num;
glGenTextures(1,&num);
SDL_Surface* img=SDL_LoadBMP(filename);
glBindTexture(GL_TEXTURE_2D,num);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,img->w,img->h,0,GL_RGB,GL_UNSIGNED_SHORT,img->pixels);
glTexEnvi(GL_TEXTURE_2D,GL_TEXTURE_ENV_MODE,GL_MODULATE); //maybe just this
SDL_FreeSurface(img);
texture.push_back(num);
return num;
}
objloader::objloader()
{
//at default we set all booleans to false, so we don't use anything
ismaterial=false;
isnormals=false;
istexture=false;
}
最佳答案
assert 宏只接受一个参数。
编译器会求值
!mtlin.is_open(),"2"
作为一个表达式。根据 逗号运算符，返回最右边表达式的结果。
所以你的断言等同于:
assert("2")
关于c++ - 断言加载文件失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34301327/