矢量函数

本文介绍了矢量函数的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

你好 如果有人可以向我解释下面的代码会很棒。 //两个向量之间的返回角度 const float inline Angle（const CVector& normal）const { 返回acosf（* this％normal）; } //用正常向量反射此向量表面 const CVector内联反射（const CVector& normal）const { const CVector vec（* this | 1）; //规范化这个载体 return（vec - normal * 2.0 *（vec％normal））*！* this; } //围绕法线旋转角度 const CVector内联旋转（常量浮动角度，常量CVector&正常）const { const float cosine = cosf（angle）; const float sine = sinf（angle）; 返回CVector（* this * cosine +（（正常） * * this）*（1.0f - 余弦））* 正常+（*这^正常）*正弦）; } 这产生了以下错误： vector.h：220：错误：声明没有声明任何内容 vector.h：220：错误：`inline'之前的语法错误' vector.h：226：错误：ISO C ++禁止在返回类型中定义类型 vector.h：226：错误：语法`inline'之前的错误'' vector.h：233：错误：`inline'之前的语法错误'' vector.h：236：错误：`angle''是未在此范围内声明 vector.h：238：错误：返回'之前'语法错误 ％和^产生什么？为什么在 函数定义的末尾还有一个const？ 感谢和问候 Michael

Hello If someone could explain the code below to me would be great. // return angle between two vectors const float inline Angle(const CVector& normal) const { return acosf(*this % normal); } // reflect this vector off surface with normal vector const CVector inline Reflection(const CVector& normal) const { const CVector vec(*this | 1); // normalize this vector return (vec - normal * 2.0 * (vec % normal)) * !*this; } // rotate angle degrees about a normal const CVector inline Rotate(const float angle, const CVector& normal) const { const float cosine = cosf(angle); const float sine = sinf(angle); return CVector(*this * cosine + ((normal * *this) * (1.0f - cosine)) * normal + (*this ^ normal) * sine); } This is producing the following errors: vector.h:220: error: declaration does not declare anything vector.h:220: error: syntax error before `inline'' vector.h:226: error: ISO C++ forbids defining types within return type vector.h:226: error: syntax error before `inline'' vector.h:233: error: syntax error before `inline'' vector.h:236: error: `angle'' was not declared in this scope vector.h:238: error: syntax error before `return'' What do % and ^ produce? Why is there a const also at the end of the function definition? THANKS and regards Michael

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" Michael Sgier" < SG *** @ nospam.ch> schrieb im Newsbeitrag news：43 ********************** @ news.sunrise.ch ... "Michael Sgier" <sg***@nospam.ch> schrieb im Newsbeitrag news:43**********************@news.sunrise.ch... 你好如果有人能解释下面的代码对我来说会很棒。 //两个向量之间的返回角度 const float inline Angle（const CVector& normal） const 返回acosf（* this％normal）; //用法线向量反射此向量表面 const CVector inline Reflection （const CVector& normal）const {const CVector vec（* this | 1）; //规范化这个向量 return（vec - normal * 2.0 *（vec％normal））*！* this; } //旋转角度约为法线 const CVector inline Rotate（常量浮点角，常量CVector& normal） const { const float cosine = cosf（angle）; const float sine = sinf（angle）; <返回CVector（* this * cosine +（（normal * * this）*（1.0f - cosine））* normal +（* this ^ normal）* sine）; } 这产生了以下错误： vector.h：220：错误：声明没有声明任何内容 vector.h：220：错误：在内联之前的语法错误' vector.h：226：错误：ISO C ++禁止在返回类型中定义类型 vector.h：226：错误：内联之前的语法错误 vector.h：233：错误：`inline'之前的语法错误' vector.h：236：错误：`angle''未在此范围内声明 vector.h：238：错误：语法'return''之前的错误 粘贴整个班级。或者更好：尽可能减少你的代码和 然后在这里粘贴你的课程。 ％和^会产生什么？ ％是模数运算符。它返回除法的余数。 ^是按位异或运算符。它比较每一位。如果其中一个 为0而另一个为1，则结果中的相应位也为1， 否则为0. 为什么在函数定义的末尾还有一个const？ 如果将 函数声明为const，则不允许类的函数修改成员变量。 感谢和问候 Michael Hello If someone could explain the code below to me would be great. // return angle between two vectors const float inline Angle(const CVector& normal) const { return acosf(*this % normal); } // reflect this vector off surface with normal vector const CVector inline Reflection(const CVector& normal) const { const CVector vec(*this | 1); // normalize this vector return (vec - normal * 2.0 * (vec % normal)) * !*this; } // rotate angle degrees about a normal const CVector inline Rotate(const float angle, const CVector& normal) const { const float cosine = cosf(angle); const float sine = sinf(angle); return CVector(*this * cosine + ((normal * *this) * (1.0f - cosine)) * normal + (*this ^ normal) * sine); } This is producing the following errors: vector.h:220: error: declaration does not declare anything vector.h:220: error: syntax error before `inline'' vector.h:226: error: ISO C++ forbids defining types within return type vector.h:226: error: syntax error before `inline'' vector.h:233: error: syntax error before `inline'' vector.h:236: error: `angle'' was not declared in this scope vector.h:238: error: syntax error before `return'' Paste your whole class. Or better: Reduce your code as much as possible and then paste your class here. What do % and ^ produce? % is the modulus operator. It returns the remainder of a division. ^ is the bitwise-exclusive-or operator. It compares each bit. If one of them is 0 and the other one is 1, the corresponding bit in the result is also 1, otherwise it is 0. Why is there a const also at the end of the function definition? Functions of a class are not allowed to modify the member variables if a function was declared as const. THANKS and regards Michael

问候Chris

Greetings Chris

/ * const float inline Angle（const CVector& normal）const { 返回acosf（* this％normal）; } * / ％以上应该是标量乘积，以便计算* this 与正常之间的角度，这通常是使用％来交叉 产品是不好的，它经常被用在像这样的代码中。将它用于 点/标量产品更奇怪。 只要对这种奇怪的评论，如果我知道 哪条线是哪条（例如哪条错误对应哪条线）。我打赌 某些地方的某些声明错过了（也许标题 不是自包含的，或者需要特定的包含顺序， 无论如何，打败我没有看到更多的代码.. :) /* const float inline Angle(const CVector& normal) const { return acosf(*this % normal); } */ Above the % should be scalar product so that the angle between *this and normal would be computed, it''s generally a bad to use % for cross product, which it is often seen used in code like this. Using it for dot/scalar product is even more strange. Just commenting on that oddity, I could comment on the errors if I knew which line was which (eg. which error correspond to which line). I bet somewhere along the line some declaration was missed (maybe the headers are not self-contained or require specific order of inclusion, whatever, beats me w/o seeing more of the code.. :)

我只是无法再拒绝回复..我一直盯着代码 难以置信：真的奇怪地使用了运算符重载。 +， - ，/，* .. 仍然很酷且很有用，因为其含义很容易理解， 但......这里发生的事情是无法相信的。令人难以置信的东西..没有 进攻！ 8P I just cannot resisting replying again.. I keep staring at the code in disbelief: really bizarre use of operator overloading. +, -, /, * .. are are still cool and useful since the meaning is easily understood, but... what is happening here is beyond belief.. incredible stuff.. no offence! 8P