无论在何处在什么地方，我们都或多或少的接触到数学知识。特别是在客户端中，从打开界面的那一刻起就有太多与数学扯上的关联，如打开窗口的大小，窗口的位置，窗口里面的元件对象，以及UI的坐标等等。而在进入游戏之后，不仅有这些坐标，还有了世界的坐标，以及场景坐标，还有粒子对象的各种属性值。但为什么要扩展ogre的数学库呢？就让我们看看有哪些类型的吧。
CODE
文件math/base.h
/**
* PAP Engine ( -- )
* $Id math.h
* @link -- for the canonical source repository
* @copyright Copyright (c) 2013-2014 viticm( viticm@126.com )
* @license
* @user viticm<viticm@126.com/viticm.ti@gmail.com>
* @date 2014-3-12 11:15:08
* @uses the base config macros and defines, also with system include
*/
#ifndef VENGINE_MATH_BASE_H_
#define VENGINE_MATH_BASE_H_ #include "vengine/config.h" namespace vengine_math { namespace base { struct VENGINE_API twofloat_vector_t {
public:
inline twofloat_vector_t& operator = (const twofloat_vector_t& vector) {
x = vector.x;
y = vector.y;
return *this;
} inline bool operator == (const twofloat_vector_t& vector) const {
return (x == vector.x && y == vector.y);
} inline bool operator != (const twofloat_vector_t& vector) const {
return ( x != vector.x || y != vector.y );
} inline twofloat_vector_t operator +
(const twofloat_vector_t& vector) const {
twofloat_vector_t sum;
sum.x = x + vector.x;
sum.y = y + vector.y;
return sum;
} inline twofloat_vector_t operator -
(const twofloat_vector_t& vector) const {
twofloat_vector_t diff;
diff.x = x - vector.x;
diff.y = y - vector.y;
return diff;
} inline twofloat_vector_t operator * (float scalar ) const {
twofloat_vector_t prod;
prod.x = scalar * x;
prod.y = scalar * y;
return prod;
} inline friend twofloat_vector_t operator *
(float scalar, const twofloat_vector_t& vector) {
twofloat_vector_t prod;
prod.x = scalar * vector.x;
prod.y = scalar * vector.y;
return prod;
} inline float length() const;
float normalise(float aimlength = 1.0f);
public:
twofloat_vector_t() : x(0.0f), y(0.0f) {}
twofloat_vector_t(float _x, float _y) : x(_x), y(_y) {}
public:
float x;
float y;
}; //tow int32_t vector struct
struct VENGINE_API twoint_vector_t {
public:
twoint_vector_t() : x(), y() {}
twoint_vector_t(int32_t _x, int32_t _y) : x(_x), y(_y) {}
public:
int32_t x;
int32_t y;
}; struct VENGINE_API threefloat_vector_t {
public:
inline threefloat_vector_t& operator =
(const threefloat_vector_t& vector) {
x = vector.x;
y = vector.y;
z = vector.z;
return *this;
} inline bool operator == ( const threefloat_vector_t& vector) const {
return (x == vector.x && y == vector.y && z == vector.z);
} inline bool operator != ( const threefloat_vector_t& vector ) const {
return (x != vector.x || y != vector.y || z != vector.z);
} inline threefloat_vector_t operator +
(const threefloat_vector_t& vector) const {
threefloat_vector_t sum;
sum.x = x + vector.x;
sum.y = y + vector.y;
sum.z = z + vector.z;
return sum;
} inline threefloat_vector_t operator -
(const threefloat_vector_t& vector) const {
threefloat_vector_t diff;
diff.x = x - vector.x;
diff.y = y - vector.y;
diff.z = z - vector.z;
return diff;
} inline threefloat_vector_t operator * (const float& mult) const {
threefloat_vector_t vector;
vector.x = x * mult;
vector.y = y * mult;
vector.z = z * mult;
return vector;
} inline float length() const; float normalise(float aimlength = 1.0f); public:
threefloat_vector_t() : x(0.0f), y(0.0f), z(0.0f) {}
threefloat_vector_t(float _x, float _y, float _z) : x(_x), y(_y), z(_z) {}
public:
float x;
float y;
float z;
}; struct VENGINE_API threeint_vector_t {
public:
threeint_vector_t() : x(), y(), z() {}
threeint_vector_t(int32_t _x, int32_t _y, int32_t _z) :
x(_x), y(_y), z(_z) {}
public:
int32_t x;
int32_t y;
int32_t z;
}; struct VENGINE_API floatray {
public:
threefloat_vector_t origin;
threefloat_vector_t direction;
}; }; //namespace base }; //namespace vengine_math #endif //VENGINE_MATH_BASE_H_
总结
从上面的代码中不难看出，扩展的数学库将二维坐标、三维坐标，以整型与浮点的形式进行了结构体的封装，而这些正是在3D游戏中经常用到的各种坐标数据类型。floatray为最后一个封装，是屏幕射线的结构，一个是起点坐标，一个是方向的坐标，两个坐标组成了一条线。学习过立体几何的都应该知道，在点与点之间这条直线自然就确定了一个方向。
这两节都讲的比较简单，接下来会讲一下客户端的性能接口模块，其实性能接口就是在引擎接口中实现了的，我们下节再说。