向量下标超出范围错误 - 如何修复此特定错误？

Question

概览

我一直在研究 OpenGL 3.3 渲染引擎，好消息是，如果我对对象的值进行硬编码，它们将完美呈现。坏消息是，在尝试加载 .obj 文件时，我运行遇到了严重的问题。

我使用 GLFW、GLM 和 GLEW 这并不重要，它可能会有所帮助。

N.B。我的 .obj 加载器基于找到的 here.

问题

当我运行我的代码时，我只是得到错误：

调试断言失败！
线路：1201
表达式：向量下标超出范围

我该如何解决这个问题？！

我已经调试了代码，我知道是哪几行导致了错误，但在进一步挖掘时我发现它试图索引一个下标为“0”的向量，所以我试图为容器初始化一些值，但是错误仍然存在。

代码

这是全部代码，请向下滚动查看具体内容。

OBJLoader.cpp

bool OBJLoader::loadGLDataFromOBJ(){

    bool processed = false;
    while (true){

        char currentLine[128];
        int res = fscanf(file, "%s", currentLine);
        if (res == EOF){

            break;
        }

        if (strcmp(currentLine, "v") == 0){
            Vector3f vertex;
            fscanf(file, "%f %f %f\n", &vertex.x, &vertex.y, &vertex.z);
            raw_vPositions.push_back(vertex);
        }
        else if (strcmp(currentLine, "vt") == 0){
            Vector2f uv;
            fscanf(file, "%f %f\n", &uv.x, &uv.y);
            raw_vTextureCoords.push_back(uv);
        }
        else if (strcmp(currentLine, "vn") == 0){
            Vector3f normal;
            fscanf(file, "%f %f %f\n", &normal.x, &normal.y, &normal.z);
            raw_vNormals.push_back(normal);
        }
        else if (strcmp(currentLine, "f") == 0){
            unsigned int vertexData1[3], vertexData2[3], vertexData3[3];
            int matches = fscanf(file, "%d/%d/%d %d/%d/%d %d/%d/%d\n",
                &vertexData1[0], &vertexData1[0], &vertexData1[0],
                &vertexData2[1], &vertexData2[1], &vertexData2[1],
                &vertexData3[2], &vertexData3[2], &vertexData3[2]);
            if (matches != 9){
                printf("File can't be read by our simple parser : ( Try exporting with other options\n");
                return false;
            }

            if (!processed){
                gl_vTextureCoords.resize(raw_vPositions.size() * 2);
                gl_vNormals.resize(raw_vPositions.size() * 3);
                processed = true;
            }

            processVertex(vertexData1);
            processVertex(vertexData2);
            processVertex(vertexData3);
        }
    }

    gl_vPositions.resize(raw_vPositions.size() * 3);
    gl_vIndexBuffer.resize(indices.size());

    int vertexPointer = 0;
    for (int i = 0; i < raw_vPositions.size(); i++){
        gl_vPositions[vertexPointer++] = raw_vPositions[i].x;
        gl_vPositions[vertexPointer++] = raw_vPositions[i].y;
    }

    for (int j = 0; j < indices.size(); j++) gl_vIndexBuffer[j] = indices[j];

    return true;
}

void OBJLoader::processVertex(unsigned int vertexData[]){
    int currentVertexPointer = *(vertexData) - 1;
    indices.push_back(currentVertexPointer);

    Vector2f currentTexture = raw_vTextureCoords[*(vertexData+1) - 1];
    gl_vTextureCoords[currentVertexPointer * 2] = currentTexture.x;
    gl_vTextureCoords[currentVertexPointer * 2 + 1] = currentTexture.y;

    Vector3f currentNormal = raw_vNormals[*(vertexData + 2) - 1];
    gl_vNormals[currentVertexPointer * 3] = currentNormal.x;
    gl_vNormals[currentVertexPointer * 3 + 1] = currentNormal.y;
    gl_vNormals[currentVertexPointer * 3 + 2] = currentNormal.z;

}


bool OBJLoader::loadOBJFromFile(const char* filePath){
    file = fopen(filePath, "r");
    if (!file){
        printf("Impossible to open the file !\n");
        return false;
    }
    else{
        printf("File opened: %s", filePath);
    }
    return true;
}



std::vector<float> OBJLoader::getPositions(){
    return this->gl_vPositions;
}
std::vector<float> OBJLoader::getTextureCoords(){
    return this->gl_vTextureCoords;
}
std::vector<float> OBJLoader::getNormals(){
    return this->gl_vNormals;
}
std::vector<unsigned short> OBJLoader::getIndexData(){
    return this->gl_vIndexBuffer;
}

OBJLoader.h

#include "glm/glm.hpp"
#include <vector>

typedef glm::vec3 Vector3f;
typedef glm::vec2 Vector2f;

typedef std::vector<Vector3f> List_Vec3;
typedef std::vector<Vector2f> List_Vec2;
typedef std::vector<unsigned short> List_Int;

class OBJLoader{
private:
    //These will be populated and then outputted to the user.
    std::vector<unsigned short> gl_vIndexBuffer = std::vector<unsigned short>(10);
    std::vector<float> gl_vPositions = std::vector<float>(10);
    std::vector<float> gl_vTextureCoords = std::vector<float>(10);
    std::vector<float> gl_vNormals = std::vector<float>(10);

    //These come from the obj file.
    List_Int indices;
    List_Vec3 raw_vPositions;
    List_Vec2 raw_vTextureCoords;
    List_Vec3 raw_vNormals;

    FILE* file; //The file of the obj.

    //Private functions
    bool loadOBJFromFile(const char* filePath); //Populates the file.
    bool loadGLDataFromOBJ();

    void processVertex(unsigned int[]);

public:
    OBJLoader(){}; //The default constructor.

    bool loadGLDataFromFile(const char* filePath); //Returns true if data loaded.

    std::vector<float> getPositions();
    std::vector<float> getTextureCoords();
    std::vector<float> getNormals();
    std::vector<unsigned short> getIndexData();

};

详情

这个功能似乎让我很伤心：

void OBJLoader::processVertex(unsigned int vertexData[]){
    int currentVertexPointer = *(vertexData) - 1;
    indices.push_back(currentVertexPointer);

    Vector2f currentTexture = raw_vTextureCoords[*(vertexData+1) - 1];
    gl_vTextureCoords[currentVertexPointer * 2] = currentTexture.x;
    gl_vTextureCoords[currentVertexPointer * 2 + 1] = currentTexture.y;

    Vector3f currentNormal = raw_vNormals[*(vertexData + 2) - 1];
    gl_vNormals[currentVertexPointer * 3] = currentNormal.x;
    gl_vNormals[currentVertexPointer * 3 + 1] = currentNormal.y;
    gl_vNormals[currentVertexPointer * 3 + 2] = currentNormal.z;
}

更具体地说，这些行：

gl_vTextureCoords[currentVertexPointer * 2] = currentTexture.x;
gl_vTextureCoords[currentVertexPointer * 2 + 1] = currentTexture.y;

gl_vNormals[currentVertexPointer * 3] = currentNormal.x;
gl_vNormals[currentVertexPointer * 3 + 1] = currentNormal.y;
gl_vNormals[currentVertexPointer * 3 + 2] = currentNormal.z;

出于某种原因，如果我继续跨过 while 循环，它会在第一次迭代时中断，并且在检查下标的值时，它等于 0，因此它调用类似：

gl_vTextureCoords[0] = currentTexture.x;
gl_vTextureCoords[1] = currentTexture.y;

这在理论上和实践中都应该存在。在 class 中，我定义向量将用 10 个空值初始化，而在运行中，当循环达到其 'f' 值时，它无论如何都会调整列表的大小，所以为什么为零这样一个硬数字？

Answer 1

错误在这里

unsigned int vertexData1[3], vertexData2[3], vertexData3[3];
int matches = fscanf(file, "%d/%d/%d %d/%d/%d %d/%d/%d\n",
   &vertexData1[0], &vertexData1[0], &vertexData1[0],
   &vertexData2[1], &vertexData2[1], &vertexData2[1],
   &vertexData3[2], &vertexData3[2], &vertexData3[2]);

我很确定你的意思是这样的：

unsigned int vertexData1[3], vertexData2[3], vertexData3[3];
int matches = fscanf(file, "%d/%d/%d %d/%d/%d %d/%d/%d\n",
   &vertexData1[0], &vertexData1[1], &vertexData1[2],
   &vertexData2[0], &vertexData2[1], &vertexData2[2],
   &vertexData3[0], &vertexData3[1], &vertexData3[2]);

或者也许：

unsigned int vertexData1[3], vertexData2[3], vertexData3[3];
int matches = fscanf(file, "%d/%d/%d %d/%d/%d %d/%d/%d\n",
   &vertexData1[0], &vertexData2[0], &vertexData3[0],
   &vertexData1[1], &vertexData2[1], &vertexData3[1],
   &vertexData1[2], &vertexData3[2], &vertexData3[2]);

这是一个很好的例子，说明了为什么老派 "C" 风格的编程是一门垂死的艺术——犯下难以诊断的后果的简单错误太容易了。

向量下标超出范围错误 - 如何修复此特定错误？

Vector Subscript out of range error - How can i fix this SPECIFIC error?

c++

opengl

vector

range

subscript

概览

问题

代码

详情