axmol/cocos2dx/support/CCPointExtension.cpp

/****************************************************************************
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2007      Scott Lembcke
Copyright (c) 2010      Lam Pham

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

NS_CC_BEGIN

#define kPointEpsilon FLT_EPSILON

float
ccpLength(const Point& v)
{
    return v.getLength();
}

float
ccpDistance(const Point& v1, const Point& v2)
{
    return (v1 - v2).getLength();
}

Point
ccpNormalize(const Point& v)
{
    return v.normalize();
}

Point
ccpForAngle(const float a)
{
    return Point::forAngle(a);
}

float
ccpToAngle(const Point& v)
{
    return v.getAngle();
}

Point ccpLerp(const Point& a, const Point& b, float alpha)
{
    return a.lerp(b, alpha);
}

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

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

Point ccpFromSize(const Size& s)
{
    return Point(s);
}

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

bool ccpFuzzyEqual(const Point& a, const Point& b, float var)
{
	return a.fuzzyEquals(b, var);
}

Point ccpCompMult(const Point& a, const Point& b)
{
    return ccp(a.x * b.x, a.y * b.y);
}

float ccpAngleSigned(const Point& a, const Point& b)
{
	return a.getAngle(b);
}

Point ccpRotateByAngle(const Point& v, const Point& pivot, float angle)
{
	return v.rotateByAngle(pivot, angle);
}


bool ccpSegmentIntersect(const Point& A, const Point& B, const Point& C, const Point& D)
{
    float S, T;

    if( ccpLineIntersect(A, B, C, D, &S, &T )
        && (S >= 0.0f && S <= 1.0f && T >= 0.0f && T <= 1.0f) )
        return true;

    return false;
}

Point ccpIntersectPoint(const Point& A, const Point& B, const Point& C, const Point& D)
{
    float S, T;

    if( ccpLineIntersect(A, B, C, D, &S, &T) )
    {
        // Point of intersection
        Point P;
        P.x = A.x + S * (B.x - A.x);
        P.y = A.y + S * (B.y - A.y);
        return P;
    }

    return PointZero;
}

bool ccpLineIntersect(const Point& A, const Point& B, 
                      const Point& C, const Point& D,
                      float *S, float *T)
{
    // FAIL: Line undefined
    if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
    {
        return false;
    }
    const float BAx = B.x - A.x;
    const float BAy = B.y - A.y;
    const float DCx = D.x - C.x;
    const float DCy = D.y - C.y;
    const float ACx = A.x - C.x;
    const float ACy = A.y - C.y;

    const float denom = DCy*BAx - DCx*BAy;

    *S = DCx*ACy - DCy*ACx;
    *T = BAx*ACy - BAy*ACx;

    if (denom == 0)
    {
        if (*S == 0 || *T == 0)
        { 
            // Lines incident
            return true;   
        }
        // Lines parallel and not incident
        return false;
    }

    *S = *S / denom;
    *T = *T / denom;

    // Point of intersection
    // CGPoint P;
    // P.x = A.x + *S * (B.x - A.x);
    // P.y = A.y + *S * (B.y - A.y);

    return true;
}

float ccpAngle(const Point& a, const Point& b)
{
    float angle = acosf(ccpDot(ccpNormalize(a), ccpNormalize(b)));
    if( fabs(angle) < kPointEpsilon ) return 0.f;
    return angle;
}

NS_CC_END