MA-software-rendering/Sourse/Math/sourse/Math.cpp

#include "MaMath.h"
#include <math.h>

float MATH_abs(float val)
{
	if (val > 0)
	{
		return val;
	}
	else
	{
		return -val;
	}
}
void MATH_clamp(float* val, float min, float max) {
	if (*val > max)
		*val = max;
	if (*val < min)
		*val = min;
}
void MATH_CrossProduct(float v[3], float v1[3], float v2[3])
{
	v[0] = v1[1] * v2[2] - v1[2] * v2[1];
	v[1] = v1[2] * v2[0] - v1[0] * v2[2];
	v[2] = v1[0] * v2[1] - v1[1] * v2[0];
}
float MATH_DotProduct(float v1[3], float v2[3])
{
	return float(v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2]);
}
void MATH_ScalarMultiplication(float v1[3], float s)
{
	v1[0] *= s;
	v1[1] *= s;
	v1[2] *= s;
}
void MATH_VectorSum(float v[3], float v1[3], float v2[3])
{
	v[0] = v1[0] + v2[0];
	v[1] = v1[1] + v2[1];
	v[2] = v1[2] + v2[2];
}
void MATH_VectorDifference(float v[3], float v1[3], float v2[3])
{
	v[0] = v1[0] - v2[0];
	v[1] = v1[1] - v2[1];
	v[2] = v1[2] - v2[2];
}
void MATH_RotateZAroundCenter(float v1[3], float angel)
{
	float sinx = float(sin(angel));
	float cosx = float(cos(angel));
	float vnew[2];
	vnew[0] = v1[0] * cosx - v1[1] * sinx;
	vnew[1] = v1[0] * sinx + v1[1] * cosx;
	v1[0] = vnew[0];
	v1[1] = vnew[1];
}
void MATH_RotateYAroundCenter(float v1[3], float angel)
{
	float sinx = float(sin(angel));
	float cosx = float(cos(angel));
	float vnew[2];
	vnew[0] = v1[0] * cosx - v1[2] * sinx;
	vnew[1] = v1[0] * sinx + v1[2] * cosx;
	v1[0] = vnew[0];
	v1[2] = vnew[1];
}
void MATH_RotateXAroundCenter(float v1[3], float angel)
{
	float vnew[2];
	float sinx = float(sin(angel));
	float cosx = float(cos(angel));
	vnew[0] = v1[1] * cosx - v1[2] * sinx;
	vnew[1] = v1[1] * sinx + v1[2] * cosx;
	v1[1] = vnew[0];
	v1[2] = vnew[1];
}

void MATH_RotateArbAxes(float RotVector[3], float axs_pos[3], float Point[3], float rot_angel)
{

	MATH_VectorDifference(Point, Point, axs_pos);

	float z_angel = float(atan(RotVector[1] / RotVector[0]));
	if (RotVector[1] > 0 and RotVector[0] < 0)
	{
		z_angel = (Pi + z_angel);
	}
	else
	{
		if (RotVector[1] < 0 and RotVector[0] < 0)
		{
			z_angel = -(Pi - z_angel);
		}
	}

	float c = float(RotVector[0] * RotVector[0] + RotVector[1] * RotVector[1]);
	float y_angel = float(atan(RotVector[2] / sqrt(c)));

	MATH_RotateZAroundCenter(Point, -z_angel);
	MATH_RotateYAroundCenter(Point, -y_angel);

	MATH_RotateXAroundCenter(Point, rot_angel);

	MATH_RotateYAroundCenter(Point, y_angel);
	MATH_RotateZAroundCenter(Point, z_angel);

	MATH_VectorSum(Point, Point, axs_pos);
}
float MATH_VectorMagnetude(float v[3])
{
	float s = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
	return float( sqrt(s));
}
void MATH_CopyVector(float v1[3], float v2[3])
{
	v1[0] = v2[0];
	v1[1] = v2[1];
	v1[2] = v2[2];
}
void MATH_MakeUnitVector(float v[3])
{
	MATH_ScalarMultiplication(v, 1 / MATH_VectorMagnetude(v));
}
void MATH_ScalarSum(float v[3], float s)
{
	v[0] += s;
	v[1] += s;
	v[2] += s;
}
float MATH_AngelBetweenTwoVectors(float v1[3], float v2[3])
{
	return float(acos(MATH_DotProduct(v1, v2) / (MATH_VectorMagnetude(v1) * MATH_VectorMagnetude(v2))));
}
int MATH_factorial(int n)
{
	int answ = 1;
	for (int i = 2; i < n+1; i++) { answ *= i; }
	return answ;
}
float MATH_Power(float x, float n)
{
	float answ = 1;
	for (int i = 0; i < n; i++)	{ answ *= x; }
	return answ;
}
float MATH_sinf(float x)
{
	float power[4];

	power[0] =        x * x * x;
	power[1] = power[0] * x * x;
	power[2] = power[1] * x * x;
	power[3] = power[2] * x * x;

	return (x - (power[0] / 6)
		      + (power[1] / 120)
		      - (power[2] / 5040)
		      + (power[3] / 362880));

	/*return (x - MATH_Power(x, 3) / MATH_factorial(3)
			  + MATH_Power(x, 5) / MATH_factorial(5)
			  - MATH_Power(x, 7) / MATH_factorial(7)
			  + MATH_Power(x, 9) / MATH_factorial(9));*/
}
//float MATH_own_cosF(float x)
//{
	//float sin = MATH_sinf(x);
	//return sqrt(1.0 - sin * sin);
//}
//float MATH_own_tanF(float x)
//{
	//float sin = MATH_sinf(x);
	//return (sin/(1 - sin*sin));
//}
double MATH_sin(float s) { return sin(s); }
double MATH_log(float s) { return log(s); }
double MATH_asin(float s) { return asin(s); }
double MATH_cos(float s) { return cos(s); }
double MATH_acos(float s) { return acos(s); }
double MATH_tan(float s) { return tan(s); }
double MATH_atan(float s) { return atan(s); }
double MATH_sqrt(float s) { return sqrt(s); }