zeus/CVector2f.cpp

53 lines
1.1 KiB
C++

#include "CVector2f.hpp"
#include <memory.h>
#include <cmath>
#include <assert.h>
#include "Math.hpp"
const CVector2f CVector2f::skOne = CVector2f(1.0);
const CVector2f CVector2f::skNegOne = CVector2f(-1.0);
const CVector2f CVector2f::skZero;
float CVector2f::getAngleDiff(const CVector2f& a, const CVector2f& b)
{
float mag1 = a.length();
float mag2 = b.length();
if (!mag1 || !mag2)
return 0;
float theta = acosf(a.dot(b) / (mag1 * mag2));
return theta;
}
CVector2f CVector2f::slerp(const CVector2f& a, const CVector2f& b, float t)
{
if (t <= 0.0f)
return a;
if (t >= 1.0f)
return b;
CVector2f ret;
float mag = sqrtf(a.dot(a) * b.dot(b));
float prod = a.dot(b) / mag;
if (fabsf(prod) < 1.0)
{
const double sign = (prod < 0.0) ? -1.0 : 1.0;
const double theta = acos(sign * prod);
const double s1 = sin (sign * t * theta);
const double d = 1.0 / sin(theta);
const double s0 = sin((1.0 - t) * theta);
ret.x = (float)(a.x * s0 + b.x * s1) * d;
ret.y = (float)(a.y * s0 + b.y * s1) * d;
return ret;
}
return a;
}