axmol/cocos2dx/cocoa/CCGeometry.cpp

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Copyright (c) 2010 cocos2d-x.org

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#include "CCGeometry.h"
#include "ccMacros.h"
#include <algorithm>

// implementation of Point
NS_CC_BEGIN

Point::Point(void) : x(0), y(0)
{
}

Point::Point(float xx, float yy) : x(xx), y(yy)
{
}

Point::Point(const Point& other) : x(other.x), y(other.y)
{
}

Point::Point(const Size& size) : x(size.width), y(size.height)
{
}

Point& Point::operator= (const Point& other)
{
    setPoint(other.x, other.y);
    return *this;
}

Point& Point::operator= (const Size& size)
{
    setPoint(size.width, size.height);
    return *this;
}

Point Point::operator+(const Point& right) const
{
    return Point(this->x + right.x, this->y + right.y);
}

Point Point::operator-(const Point& right) const
{
    return Point(this->x - right.x, this->y - right.y);
}

Point Point::operator-() const
{
	return Point(-x, -y);
}

Point Point::operator*(float a) const
{
    return Point(this->x * a, this->y * a);
}

Point Point::operator/(float a) const
{
	CCASSERT(a!=0, "CCPoint division by 0.");
    return Point(this->x / a, this->y / a);
}

void Point::setPoint(float xx, float yy)
{
    this->x = xx;
    this->y = yy;
}

bool Point::equals(const Point& target) const
{
    return (fabs(this->x - target.x) < FLT_EPSILON)
        && (fabs(this->y - target.y) < FLT_EPSILON);
}

bool Point::fuzzyEquals(const Point& b, float var) const
{
    if(x - var <= b.x && b.x <= x + var)
        if(y - var <= b.y && b.y <= y + var)
            return true;
    return false;
}

float Point::getAngle(const Point& other) const
{
    Point a2 = normalize();
    Point b2 = other.normalize();
    float angle = atan2f(a2.cross(b2), a2.dot(b2));
    if( fabs(angle) < FLT_EPSILON ) return 0.f;
    return angle;
}

Point Point::rotateByAngle(const Point& pivot, float angle) const
{
    return pivot + (*this - pivot).rotate(Point::forAngle(angle));
}

bool Point::isOneDemensionSegmentOverlap(float A, float B, float C, float D, float *S, float *E)
{
    float ABmin = MIN(A, B);
    float ABmax = MAX(A, B);
    float CDmin = MIN(C, D);
    float CDmax = MAX(C, D);
    
    if (ABmax < CDmin || CDmax < ABmin)
    {
        // ABmin->ABmax->CDmin->CDmax or CDmin->CDmax->ABmin->ABmax
        return false;
    }
    else
    {
        if (ABmin >= CDmin && ABmin <= CDmax)
        {
            // CDmin->ABmin->CDmax->ABmax or CDmin->ABmin->ABmax->CDmax
            if (S != nullptr) *S = ABmin;
            if (E != nullptr) *E = CDmax < ABmax ? CDmax : ABmax;
        }
        else if (ABmax >= CDmin && ABmax <= CDmax)
        {
            // ABmin->CDmin->ABmax->CDmax
            if (S != nullptr) *S = CDmin;
            if (E != nullptr) *E = ABmax;
        }
        else
        {
            // ABmin->CDmin->CDmax->ABmax
            if (S != nullptr) *S = CDmin;
            if (E != nullptr) *E = CDmax;
        }
        return true;
    }
}

bool Point::isLineIntersect(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 denom = crossProduct2Vector(A, B, C, D);
    
    if (denom == 0)
    {
        // Lines parallel or overlap
        return false;
    }
    
    if (S != nullptr) *S = crossProduct2Vector(C, D, C, A) / denom;
    if (T != nullptr) *T = crossProduct2Vector(A, B, C, A) / denom;
    
    return true;
}

bool Point::isLineParallel(const Point& A, const Point& B,
                           const Point& C, const Point& D)
{
    // FAIL: Line undefined
    if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
    {
        return false;
    }
    
    if (crossProduct2Vector(A, B, C, D) == 0)
    {
        // line overlap
        if (crossProduct2Vector(C, D, C, A) == 0 || crossProduct2Vector(A, B, C, A) == 0)
        {
            return false;
        }
        
        return true;
    }
    
    return false;
}

bool Point::isLineOverlap(const Point& A, const Point& B,
                            const Point& C, const Point& D)
{
    // FAIL: Line undefined
    if ( (A.x==B.x && A.y==B.y) || (C.x==D.x && C.y==D.y) )
    {
        return false;
    }
    
    if (crossProduct2Vector(A, B, C, D) == 0 &&
        (crossProduct2Vector(C, D, C, A) == 0 || crossProduct2Vector(A, B, C, A) == 0))
    {
        return true;
    }
    
    return false;
}

bool Point::isSegmentOverlap(const Point& A, const Point& B, const Point& C, const Point& D, Point* S, Point* E)
{
    
    if (isLineOverlap(A, B, C, D))
    {
        return isOneDemensionSegmentOverlap(A.x, B.x, C.x, D.x, &S->x, &E->x) &&
        isOneDemensionSegmentOverlap(A.y, B.y, C.y, D.y, &S->y, &E->y);
    }  
    
    return false;
}

bool Point::isSegmentIntersect(const Point& A, const Point& B, const Point& C, const Point& D)
{
    float S, T;
    
    if (isLineIntersect(A, B, C, D, &S, &T )&&
        (S >= 0.0f && S <= 1.0f && T >= 0.0f && T <= 1.0f))
    {
        return true;
    }
    
    return false;
}

Point Point::getIntersectPoint(const Point& A, const Point& B, const Point& C, const Point& D)
{
    float S, T;
    
    if (isLineIntersect(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 Point::ZERO;
}

const Point Point::ZERO = Point(0, 0);

// implementation of Size

Size::Size(void) : width(0), height(0)
{
}

Size::Size(float w, float h) : width(w), height(h)
{
}

Size::Size(const Size& other) : width(other.width), height(other.height)
{
}

Size::Size(const Point& point) : width(point.x), height(point.y)
{
}

Size& Size::operator= (const Size& other)
{
    setSize(other.width, other.height);
    return *this;
}

Size& Size::operator= (const Point& point)
{
    setSize(point.x, point.y);
    return *this;
}

Size Size::operator+(const Size& right) const
{
    return Size(this->width + right.width, this->height + right.height);
}

Size Size::operator-(const Size& right) const
{
    return Size(this->width - right.width, this->height - right.height);
}

Size Size::operator*(float a) const
{
    return Size(this->width * a, this->height * a);
}

Size Size::operator/(float a) const
{
	CCASSERT(a!=0, "CCSize division by 0.");
    return Size(this->width / a, this->height / a);
}

void Size::setSize(float w, float h)
{
    this->width = w;
    this->height = h;
}

bool Size::equals(const Size& target) const
{
    return (fabs(this->width  - target.width)  < FLT_EPSILON)
        && (fabs(this->height - target.height) < FLT_EPSILON);
}

const Size Size::ZERO = Size(0, 0);

// implementation of Rect

Rect::Rect(void)
{
    setRect(0.0f, 0.0f, 0.0f, 0.0f);
}

Rect::Rect(float x, float y, float width, float height)
{
    setRect(x, y, width, height);
}

Rect::Rect(const Rect& other)
{
    setRect(other.origin.x, other.origin.y, other.size.width, other.size.height);
}

Rect& Rect::operator= (const Rect& other)
{
    setRect(other.origin.x, other.origin.y, other.size.width, other.size.height);
    return *this;
}

void Rect::setRect(float x, float y, float width, float height)
{
    // CGRect can support width<0 or height<0
    // CCASSERT(width >= 0.0f && height >= 0.0f, "width and height of Rect must not less than 0.");

    origin.x = x;
    origin.y = y;

    size.width = width;
    size.height = height;
}

bool Rect::equals(const Rect& rect) const
{
    return (origin.equals(rect.origin) && 
            size.equals(rect.size));
}

float Rect::getMaxX() const
{
    return (float)(origin.x + size.width);
}

float Rect::getMidX() const
{
    return (float)(origin.x + size.width / 2.0);
}

float Rect::getMinX() const
{
    return origin.x;
}

float Rect::getMaxY() const
{
    return origin.y + size.height;
}

float Rect::getMidY() const
{
    return (float)(origin.y + size.height / 2.0);
}

float Rect::getMinY() const
{
    return origin.y;
}

bool Rect::containsPoint(const Point& point) const
{
    bool bRet = false;

    if (point.x >= getMinX() && point.x <= getMaxX()
        && point.y >= getMinY() && point.y <= getMaxY())
    {
        bRet = true;
    }

    return bRet;
}

bool Rect::intersectsRect(const Rect& rect) const
{
    return !(     getMaxX() < rect.getMinX() ||
             rect.getMaxX() <      getMinX() ||
                  getMaxY() < rect.getMinY() ||
             rect.getMaxY() <      getMinY());
}

Rect Rect::unionWithRect(const Rect & rect) const
{
    float thisLeftX = origin.x;
    float thisRightX = origin.x + size.width;
    float thisTopY = origin.y + size.height;
    float thisBottomY = origin.y;
    
    if (thisRightX < thisLeftX)
    {
        std::swap(thisRightX, thisLeftX);   // This rect has negative width
    }
    
    if (thisTopY < thisBottomY)
    {
        std::swap(thisTopY, thisBottomY);   // This rect has negative height
    }
    
    float otherLeftX = rect.origin.x;
    float otherRightX = rect.origin.x + rect.size.width;
    float otherTopY = rect.origin.y + rect.size.height;
    float otherBottomY = rect.origin.y;
    
    if (otherRightX < otherLeftX)
    {
        std::swap(otherRightX, otherLeftX);   // Other rect has negative width
    }
    
    if (otherTopY < otherBottomY)
    {
        std::swap(otherTopY, otherBottomY);   // Other rect has negative height
    }
    
    float combinedLeftX = std::min(thisLeftX, otherLeftX);
    float combinedRightX = std::max(thisRightX, otherRightX);
    float combinedTopY = std::max(thisTopY, otherTopY);
    float combinedBottomY = std::min(thisBottomY, otherBottomY);
    
    return Rect(combinedLeftX, combinedBottomY, combinedRightX - combinedLeftX, combinedTopY - combinedBottomY);
}

const Rect Rect::ZERO = Rect(0, 0, 0, 0);

NS_CC_END