为什么我的程序有一个实例，其中"Vector Subscript out of Range"？

Question

Bassicly我的代码应该从main() 中的int tt[]获取int

const int tt[] =
    {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    };

然后，该程序被暴露为基于向量的顺序给出向量的堇青石，并且如果它给出#1，则给出纹理的堇青石。根据我的cout语句tiletype = tt[count];，我可以在从int tt[]读取fith zero后判断程序崩溃，并给出错误Vector Subscript out of Range。

我认为问题属于我代码的这一部分：

  for(x = 1; x < c;++x)
    {
    for(y = 0; y < r;++y)
    {
        tiletype = tt[count];
        cout <<tiletype<<", ";
            vertices[a].position = sf::Vector2f((0+y)*ts,ts*(x+1)+80);
            vertices[b].position = sf::Vector2f((0+y)*ts, (0+x)*ts+80);
            vertices[d].position = sf::Vector2f(ts+(y*ts),(0+x)*ts+80);
            vertices[e].position = sf::Vector2f(ts+(y*ts), ts*(x+1)+80);
            vertices[a].texCoords = mapcords(tiletype,0);
            vertices[b].texCoords = mapcords(tiletype,1);
            vertices[d].texCoords = mapcords(tiletype,2);
            vertices[e].texCoords = mapcords(tiletype,3);
            a += 4; b += 4; d += 4; e += 4;count++;
    }
    row += 1;
    cout <<endl<<"Row "<<row<<": "; y = 0;
    }

这是代码的其余部分。

#include <SFML/Graphics.hpp>
#include <iostream>
using namespace std;
using namespace sf;
Vector2f mapcords(int tt,int corner);
Vector2f mapcords(int tt,int corner)
{
if(tt ==0)
{
    if (corner ==1)
    {return Vector2f(48,8 );}
    if(corner == 1)
    {return Vector2f(48,0);}
    if (corner ==2)
    {return Vector2f(56, 0);}
    if (corner == 3)
    {return sf::Vector2f(56, 8);}
}
else{
    if(corner ==0)
    {return Vector2f(0,8 );}
    if(corner == 1)
    {return Vector2f(0,0);}
    if (corner ==2)
    {return Vector2f(8, 0);}
    if (corner == 3)
    {return sf::Vector2f(8, 8);}
}
return Vector2f(0,0 );
}
class drawmap : public sf::Drawable, public sf::Transformable
{
public:
    bool load(const string& tileset,const int* tt, int ts, int r, int c, int num) 
    {
    count =0;   row =1;  a = 0;  b = 1;  d = 2;  e = 3;y=0;x=0;
        tiletex.setRepeated(true);
        if (!tiletex.loadFromFile(tileset))
            return false;
    tiletex.setRepeated(true);
    vertices.setPrimitiveType(sf::Quads);
    vertices.resize(2 * 2 * 4);
        cout <<endl<<"Row "<<row<<": ";
    for(x = 1; x < c;++x)
    {
    for(y = 0; y < r;++y)
    {
        tiletype = tt[count];
        cout <<tiletype<<", ";
            vertices[a].position = sf::Vector2f((0+y)*ts,ts*(x+1)+80);
            vertices[b].position = sf::Vector2f((0+y)*ts, (0+x)*ts+80);
            vertices[d].position = sf::Vector2f(ts+(y*ts),(0+x)*ts+80);
            vertices[e].position = sf::Vector2f(ts+(y*ts), ts*(x+1)+80);
            vertices[a].texCoords = mapcords(tiletype,0);
            vertices[b].texCoords = mapcords(tiletype,1);
            vertices[d].texCoords = mapcords(tiletype,2);
            vertices[e].texCoords = mapcords(tiletype,3);
            a += 4; b += 4; d += 4; e += 4;count++;
    }
    row += 1;
    cout <<endl<<"Row "<<row<<": "; y = 0;
    }
    return true;
    }
private:
        int row;
        int count;
    int y,x;
        int a,b,d,e;
        int tiletype;
    virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const
    {
        states.transform *= getTransform();
        states.texture = &tiletex;
        target.draw(vertices, states);
    }
    sf::VertexArray vertices;
    sf::Texture tiletex;
};

Answer 1

即使r和c正确初始化为（我假设）4，一旦循环到y = 4（即x递增）的点，就不会重置a、b、d或e——这意味着在第五个循环中，您有a = 16、b = 17、d = 19和e = 20，但您仍然尝试访问vertices[a]（以及b、d和e）。由于在此之前的顶点已调整为(2 * 2 * 4)或16，因此可以访问超出其边界的向量。因此，vector subscript out of range出现错误。

为了保持足够的顶点用于4*你想放在向量中的瓦片数量，你需要做一些事情，比如：

vertices.resize(4 * r * c);