Question

我有lib用于加载obj网格的功能... 这个功能的一部分

    case 'v':
        if(string[1] == ' ')
        {
            have_verticles = true;
            tmp_Vertex.set(0,0,0);
            sscanf(&string[2],"%f %f %f",&tmp_Vertex.x,&tmp_Vertex.y,&tmp_Vertex.z);
            Verticles.push_back(tmp_Vertex);
        }
        else if(string[1] == 't')
        {
            have_texcoords = true;
            tmp_Texcoord.set(0,0);
            sscanf(&string[2],"%f %f",&tmp_Texcoord.x,&tmp_Texcoord.y);
            TexCoords.push_back(tmp_Texcoord);
        }
        else if(string[1] == 'n')
        {
            have_normals = true;
            tmp_Normal.set(0,0,0);
            sscanf(&string[2],"%f %f %f",&tmp_Normal.x,&tmp_Normal.y,&tmp_Normal.z);
            Normals.push_back(tmp_Normal);
        }
        break;

如果我使用main.cpp编译lib作为可执行文件，一切正常但如果我将lib编译为DLL并尝试从另一个应用程序执行此函数， sscanf ingore最后2个浮点数并且只读取第一个...... 如何解决这个问题？

对不起我可怕的英语..

UPD：

示例文件（部分）

v 1.000000 -1.000000 -1.000000
v 1.000000 -1.000000 1.000000
v -1.000000 -1.000000 1.000000
v -1.000000 -1.000000 -1.000000
v 1.000000 1.000000 -0.999999
v 0.999999 1.000000 1.000001
v -1.000000 1.000000 1.000000
v -1.000000 1.000000 -1.000000

sscanf只读取第一个花车...

UPD2：字符串是

char string[256];

带有输入字符串
的sscanf（）之后
"1.000000 -1.000000 -1.000000" tmp_Vertex.x = 1.0 tmp_Vertex.y = 0.0 tmp_Vertex.z = 0.0

sscanf（）返回1 ..

全功能代码......

renderer::IMesh* CMeshOBJImporter::LoadOBJ(io::IFile* file) { bool have_verticles = false; bool have_texcoords = false; bool have_normals = false; std::vector<core::vector3f> Verticles; std::vector<core::vector2f> TexCoords; std::vector<core::vector3f> Normals; std::vector<core::vector3s> Indices; core::vector3f tmp_Vertex; core::vector2f tmp_Texcoord; core::vector3f tmp_Normal; core::vector3s tmp_Index; char string[256]; while(read_string(file,string) != 0) { switch(string[0]) { case '#': continue; case 'o': continue; case 'm': continue; case 'u': continue; case 'v': if(string[1] == ' ') { have_verticles = true; tmp_Vertex.set(0,0,0); sscanf(string + 2,"%f %f %f",&tmp_Vertex.x,&tmp_Vertex.y,&tmp_Vertex.z); Verticles.push_back(tmp_Vertex); } else if(string[1] == 't') { have_texcoords = true; tmp_Texcoord.set(0,0); sscanf(&string[2],"%f %f",&tmp_Texcoord.x,&tmp_Texcoord.y); TexCoords.push_back(tmp_Texcoord); } else if(string[1] == 'n') { have_normals = true; tmp_Normal.set(0,0,0); sscanf(&string[2],"%f %f %f",&tmp_Normal.x,&tmp_Normal.y,&tmp_Normal.z); Normals.push_back(tmp_Normal); } break; case 'f': std::vector<core::vector3s> Face; char* tok = strtok(&string[1]," \n"); while(tok != NULL) { tmp_Index.set(0,0,0); if(have_verticles && !have_texcoords && !have_normals) sscanf(tok,"%d",&tmp_Index.x); else if(have_verticles && have_texcoords && !have_normals) sscanf(tok,"%d/%d",&tmp_Index.x,&tmp_Index.y); else if(have_verticles && !have_texcoords && have_normals) sscanf(tok,"%d//%d",&tmp_Index.x,&tmp_Index.z); else if(have_verticles && have_texcoords && have_normals) sscanf(tok,"%d/%d/%d",&tmp_Index.x,&tmp_Index.y,&tmp_Index.z); tmp_Index.add(-1); Face.push_back(tmp_Index); tok = strtok(NULL," \n"); } //Triangulate face if(Face.size() > 3) { //!< If Face = Quad we use predefined vertex positions (it's faster) //!< Else we split big polygon(more than 4 vertex) on triangles if(Face.size() == 4) { Face.push_back(0); Face.push_back(0); Face[4] = Face[3]; Face[3] = Face[2]; Face[5] = Face[0]; } else { std::vector<core::vector3s> TriangulatedFaces; u32 FaceSize = Face.size()-2; for(u32 i = 0; i < FaceSize; i++) { TriangulatedFaces.push_back(Face[0 ]); TriangulatedFaces.push_back(Face[1+i]); TriangulatedFaces.push_back(Face[2+i]); } Face.clear(); Face.insert(Face.end(),TriangulatedFaces.begin(),TriangulatedFaces.end()); } } Indices.insert(Indices.end(),Face.begin(),Face.end()); break; } } renderer::CVertexArray* VertexArray = new renderer::CVertexArray(); u32 IndicesSize = Indices.size(); for(u32 i = 0; i < IndicesSize; i++) { renderer::SVertex Vertex; if(have_verticles) Vertex.Position = Verticles[Indices[i].x]; if(have_texcoords) Vertex.TexCoord = TexCoords[Indices[i].y]; if(have_normals) Vertex.Normal = Normals[Indices[i].z]; VertexArray->addVertex(Vertex); } u32 VertexFormat = renderer::EVF_VERTEX; if(have_texcoords) VertexFormat |= renderer::EVF_TEXCOORD; if(have_normals) VertexFormat |= renderer::EVF_NORMAL; VertexArray->setPrimitiveType(renderer::EPT_TRIANGLES); VertexArray->setVertexFormat(VertexFormat); renderer::IMesh* newMesh = new renderer::CMesh(VertexArray,NULL); VertexArray->release(); return newMesh; }

Answer 1

尝试将&string[2]更改为string + 2 sscanf的第一个参数应该是char*（C字符串）。

Answer 2

您的问题是您只能从角色中读取数据。请尝试以下代码：

sscanf(string.c_str(),"%f %f %f",&tmp_Vertex.x,&tmp_Vertex.y,&tmp_Vertex.z);

c_str（）：获取等效的C字符串

Answer 3

这不是一个答案，而是一个建议，太长时间无法发表评论：

定义这些函数（注意to_string是c ++ 11）

using std::string;
using std::to_string;

void sscanf_2( const char* str, const char* fmt, float *f1, float *f2 ) {
    size_t n = sscanf(str,fmt, f1, f2 );
    if (n != 2) throw std::runtime_error("sscanf_2: bad parse, str="+string(str)+" fmt="+string(fmt)+" n="+to_string(n));
}

void sscanf_3( const char* str, const char* fmt, float *f1, float *f2, float *f3 ) {
    size_t n = sscanf(str,fmt, f1, f2, f3 );
    if (n != 3) throw std::runtime_error("sscanf_3: bad parse, str="+string(str)+" fmt="+string(fmt)+" n="+to_string(n));
}

在代码中使用这些功能，将sscanf替换为sscanf_2或sscanf_3。如果sscanf无法解析所需数量的字段，它将抛出异常，您可以在程序中捕获该异常。这可能有助于你弄清楚出了什么问题。

sscanf读取1而不是3浮动

3 个答案: