package Maths
import NoWurst
import initlater Angle
import initlater Wurstunit
import initlater Real

/** PI constant */
public constant real PI			=  3.141592654
/** PI * 2 constant */
public constant real PI2 		=  6.28318
/** PI / 2 constant */
public constant real PIHALF		=  1.570796326
/** Converts Degrees to Radians */
public constant real DEGTORAD  	=  0.017453293
/** Converts Radians to Degrees */
public constant real RADTODEG  	= 57.295779513

/** Polar Projection for x Coordiante */
public function polarProjectionX( real x,  real dist, angle ang ) returns real
	return x + dist * Cos(ang.radians())

/** Polar Projection for y Coordiante */
public function polarProjectionY( real y,  real dist, angle ang ) returns real
	return y + dist * Sin(ang.radians())

/** Polar Projection for z Coordiante */
public function polarProjectionZ( real z,  real dist, angle ang ) returns real
	return z + dist * Sin(ang.radians())

/** Returns the angle between two points */
public function angleBetweenCoords ( real x1, real y1, real x2, real y2 ) returns angle
	return Atan2(y2 - y1, x2 - x1).asAngleRadians()

/** Returns the distance between two points */
public function distanceBetweenCoords ( real x1, real y1, real x2, real y2 ) returns real
	return SquareRoot((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1))

/**
 * Returns the length of the hypotenuse of a right-angle triangle with the
 * given side lengths. Does not overflow or underflow as fast as
 * SquareRoot(x^2 + y^2) does.
 */
public function hypot(real dx, real dy) returns real
	real x = dx.abs()
	real y = dy.abs()
	real t = 0
	if x > y
		t = y / x
	else if x < y
		t = x / y
		x = y
	return x * SquareRoot(1 + t * t)

/** Returns the angle of a height-slope */
public function getSlopeAngle( real z1, real z2, real dist ) returns angle
	return angle(Atan2(z2-z1, dist ))

public function int.moduloInt(int divisor) returns int
	return this - (this div divisor) * divisor


/** returns the bigger number of the two parameters */
public function max(int x, int y) returns int
	int r
	if x > y
		r = x
	else
		r = y
	return r

/** returns the bigger number of the two parameters */
public function max(real x, real y) returns real
	real r
	if x > y
		r = x
	else
		r = y
	return r


/** returns the smaller number of the two parameters */
public function min(int x, int y) returns int
	int r
	if x < y
		r = x
	else
		r = y
	return r

/** returns the smaller number of the two parameters */
public function min(real x, real y) returns real
	real r
	if x < y
		r = x
	else
		r = y
	return r

public function real.lerp(real target, real alpha) returns real
	return (this * (1.0-alpha)) + (target * alpha)

public function int.lerp(int target, real alpha) returns int
	return ((this * (1.0-alpha)) + (target * alpha)).round()


@test function minmax()
	// better test min and max, they are difficult to implement M;D
	int three = 3
	max(three,4)	.assertEquals(4)
	max(4,three)	.assertEquals(4)
	min(three,4)	.assertEquals(3)
	max(3.,4.)		.assertEquals(4.)
	min(3.,4.)		.assertEquals(3.)

@test function test_hypot()
	test_hypot_help(5,6)
	test_hypot_help(5000000.,6)
	test_hypot_help(3.,123456789.)
	test_hypot_help(543532403425324.,123456789.)
	test_hypot_help(0.0000001,0.0000000000023)
	test_hypot_help(0,0)


function test_hypot_help(real x, real y)
	hypot(x,y).assertEquals(SquareRoot(x*x + y*y), 0.0001)