/****************************************************************************
Copyright (c) 2010 cocos2d-x.org

http://www.cocos2d-x.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/

#include "CGPointExtension.h"
#include "ccMacros.h" // FLT_EPSILON
#include <stdio.h>

#define kCGPointEpsilon FLT_EPSILON

CGFloat
ccpLength(const CGPoint v)
{
	return sqrtf(ccpLengthSQ(v));
}

CGFloat
ccpDistance(const CGPoint v1, const CGPoint v2)
{
	return ccpLength(ccpSub(v1, v2));
}

CGPoint
ccpNormalize(const CGPoint v)
{
	return ccpMult(v, 1.0f/ccpLength(v));
}

CGPoint
ccpForAngle(const CGFloat a)
{
	return ccp(cosf(a), sinf(a));
}

CGFloat
ccpToAngle(const CGPoint v)
{
	return atan2f(v.y, v.x);
}

CGPoint ccpLerp(CGPoint a, CGPoint b, float alpha)
{
	return ccpAdd(ccpMult(a, 1.f - alpha), ccpMult(b, alpha));
}

float clampf(float value, float min_inclusive, float max_inclusive)
{
	if (min_inclusive > max_inclusive) {
		float ftmp;
		ftmp = min_inclusive;
		min_inclusive = max_inclusive;
		max_inclusive = min_inclusive;
	}
	return value < min_inclusive ? min_inclusive : value < max_inclusive? value : max_inclusive;
}

CGPoint ccpClamp(CGPoint p, CGPoint min_inclusive, CGPoint max_inclusive)
{
	return ccp(clampf(p.x,min_inclusive.x,max_inclusive.x), clampf(p.y, min_inclusive.y, max_inclusive.y));
}

CGPoint ccpFromSize(CGSize s)
{
	return ccp(s.width, s.height);
}

CGPoint ccpCompOp(CGPoint p, float (*opFunc)(float)){
	return ccp(opFunc(p.x), opFunc(p.y));
}

bool ccpFuzzyEqual(CGPoint a, CGPoint b, float var)
{
	if(a.x - var <= b.x && b.x <= a.x + var)
		if(a.y - var <= b.y && b.y <= a.y + var)
			return true;
	return false;
}

CGPoint ccpCompMult(CGPoint a, CGPoint b)
{
	return ccp(a.x * b.x, a.y * b.y);
}

float ccpAngleSigned(CGPoint a, CGPoint b)
{
	CGPoint a2 = ccpNormalize(a);	CGPoint b2 = ccpNormalize(b);
	float angle = atan2f(a2.x * b2.y - a2.y * b2.x, ccpDot(a2, b2));
	if( fabs(angle) < kCGPointEpsilon ) return 0.f;
	return angle;
}

CGPoint ccpRotateByAngle(CGPoint v, CGPoint pivot, float angle) {
	CGPoint r = ccpSub(v, pivot);
	float t = r.x;
	float cosa = cosf(angle), sina = sinf(angle);
	r.x = t*cosa - r.y*sina;
	r.y = t*sina + r.y*cosa;
	r = ccpAdd(r, pivot);
	return r;
}

bool ccpLineIntersect(CGPoint p1, CGPoint p2, 
					  CGPoint p3, CGPoint p4,
					  float *s, float *t){
	CGPoint p13, p43, p21;
	float d1343, d4321, d1321, d4343, d2121;
	float numer, denom;
	
	p13 = ccpSub(p1, p3);
	
	p43 = ccpSub(p4, p3);
	
	//Roughly equal to zero but with an epsilon deviation for float 
	//correction
	if (ccpFuzzyEqual(p43, CGPointZero, kCGPointEpsilon))
		return false;
	
	p21 = ccpSub(p2, p1);
	
	//Roughly equal to zero
	if (ccpFuzzyEqual(p21,CGPointZero, kCGPointEpsilon))
		return false;
	
	d1343 = ccpDot(p13, p43);
	d4321 = ccpDot(p43, p21);
	d1321 = ccpDot(p13, p21);
	d4343 = ccpDot(p43, p43);
	d2121 = ccpDot(p21, p21);
	
	denom = d2121 * d4343 - d4321 * d4321;
	if (fabs(denom) < kCGPointEpsilon)
		return false;
	numer = d1343 * d4321 - d1321 * d4343;
	
	*s = numer / denom;
	*t = (d1343 + d4321 *(*s)) / d4343;
	
	return true;
}

float ccpAngle(CGPoint a, CGPoint b)
{
	float angle = acosf(ccpDot(ccpNormalize(a), ccpNormalize(b)));
	if( fabs(angle) < kCGPointEpsilon ) return 0.f;
	return angle;
}