小编and*_*dre的帖子

这是一个初学者问题，我将如何将以下 json 字符串数组格式化为 std::string

[
  { 
    "x" : 12.1,
    "y" : 12.1,
    "z" : 12.1
  },
  { 
    "x" : 12.1,
    "y" : 12.1,
    "z" : 12.1
  },  
  { 
    "x" : 12.1,
    "y" : 12.1,
    "z" : 12.1
  },  
  { 
    "x" : 12.1,
    "y" : 12.1,
    "z" : 12.1
  }
]

这是json字符串

const std::string json =
            "[\n"
            "  {\n"
            "    \"x\" : 0,\n"
            "    \"y\" : 0,\n"
            "    \"z\" : 0\n"
            "  },\n"
            "  {\n"
            "    \"x\" : 640,\n"
            "    \"y\" …

我有一个 4x4 投影矩阵

(SCNMatrix4) 
   s = (m11 = 1.83226573, 
   m12 = 0, 
   m13 = 0, 
   m14 = 0,
   m21 = 0,
   m22 = 2.44078445,
   m23 = 0,
   m24 = 0,
   m31 = -0.00576340035, 
   m32 = -0.0016724075, 
   m33 = -1.00019991, 
   m34 = -1, 
   m41 = 0, 
   m42 = 0, 
   m43 = -0.20002, 
   m44 = 0)

我想从这个矩阵中得到焦点和焦距。