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00002
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00005 #ifndef __IRR_LINE_2D_H_INCLUDED__
00006 #define __IRR_LINE_2D_H_INCLUDED__
00007
00008 #include "irrTypes.h"
00009 #include "vector2d.h"
00010
00011 namespace irr
00012 {
00013 namespace core
00014 {
00015
00017 template <class T>
00018 class line2d
00019 {
00020 public:
00022 line2d() : start(0,0), end(1,1) {}
00024 line2d(T xa, T ya, T xb, T yb) : start(xa, ya), end(xb, yb) {}
00026 line2d(const vector2d<T>& start, const vector2d<T>& end) : start(start), end(end) {}
00028 line2d(const line2d<T>& other) : start(other.start), end(other.end) {}
00029
00030
00031
00032 line2d<T> operator+(const vector2d<T>& point) const { return line2d<T>(start + point, end + point); }
00033 line2d<T>& operator+=(const vector2d<T>& point) { start += point; end += point; return *this; }
00034
00035 line2d<T> operator-(const vector2d<T>& point) const { return line2d<T>(start - point, end - point); }
00036 line2d<T>& operator-=(const vector2d<T>& point) { start -= point; end -= point; return *this; }
00037
00038 bool operator==(const line2d<T>& other) const
00039 { return (start==other.start && end==other.end) || (end==other.start && start==other.end);}
00040 bool operator!=(const line2d<T>& other) const
00041 { return !(start==other.start && end==other.end) || (end==other.start && start==other.end);}
00042
00043
00045 void setLine(const T& xa, const T& ya, const T& xb, const T& yb){start.set(xa, ya); end.set(xb, yb);}
00047 void setLine(const vector2d<T>& nstart, const vector2d<T>& nend){start.set(nstart); end.set(nend);}
00049 void setLine(const line2d<T>& line){start.set(line.start); end.set(line.end);}
00050
00052
00053 f64 getLength() const { return start.getDistanceFrom(end); }
00054
00056
00057 T getLengthSQ() const { return start.getDistanceFromSQ(end); }
00058
00060
00061 vector2d<T> getMiddle() const
00062 {
00063 return (start + end) * (T)0.5;
00064 }
00065
00067
00068 vector2d<T> getVector() const { return vector2d<T>(end.X - start.X, end.Y - start.Y); }
00069
00071
00075 bool intersectWith(const line2d<T>& l, vector2d<T>& out) const
00076 {
00077
00078
00079 const f32 commonDenominator = (l.end.Y - l.start.Y)*(end.X - start.X) -
00080 (l.end.X - l.start.X)*(end.Y - start.Y);
00081
00082 const f32 numeratorA = (l.end.X - l.start.X)*(start.Y - l.start.Y) -
00083 (l.end.Y - l.start.Y)*(start.X -l.start.X);
00084
00085 const f32 numeratorB = (end.X - start.X)*(start.Y - l.start.Y) -
00086 (end.Y - start.Y)*(start.X -l.start.X);
00087
00088 if(equals(commonDenominator, 0.f))
00089 {
00090
00091 if(equals(numeratorA, 0.f) && equals(numeratorB, 0.f))
00092 {
00093
00094 if(l.start == start || l.end == start)
00095 out = start;
00096 else if(l.end == end || l.start == end)
00097 out = end;
00098 else
00099
00100
00101 out = ((start + end + l.start + l.end) * 0.25f);
00102
00103 return true;
00104 }
00105
00106 return false;
00107 }
00108
00109
00110
00111 const f32 uA = numeratorA / commonDenominator;
00112 if(uA < 0.f || uA > 1.f)
00113 return false;
00114
00115 const f32 uB = numeratorB / commonDenominator;
00116 if(uB < 0.f || uB > 1.f)
00117 return false;
00118
00119
00120 out.X = start.X + uA * (end.X - start.X);
00121 out.Y = start.Y + uA * (end.Y - start.Y);
00122 return true;
00123 }
00124
00126
00127 vector2d<T> getUnitVector() const
00128 {
00129 T len = (T)(1.0 / getLength());
00130 return vector2d<T>((end.X - start.X) * len, (end.Y - start.Y) * len);
00131 }
00132
00134
00136 f64 getAngleWith(const line2d<T>& l) const
00137 {
00138 vector2d<T> vect = getVector();
00139 vector2d<T> vect2 = l.getVector();
00140 return vect.getAngleWith(vect2);
00141 }
00142
00144
00146 T getPointOrientation(const vector2d<T>& point) const
00147 {
00148 return ( (end.X - start.X) * (point.Y - start.Y) -
00149 (point.X - start.X) * (end.Y - start.Y) );
00150 }
00151
00153
00154 bool isPointOnLine(const vector2d<T>& point) const
00155 {
00156 T d = getPointOrientation(point);
00157 return (d == 0 && point.isBetweenPoints(start, end));
00158 }
00159
00161
00162 bool isPointBetweenStartAndEnd(const vector2d<T>& point) const
00163 {
00164 return point.isBetweenPoints(start, end);
00165 }
00166
00168 vector2d<T> getClosestPoint(const vector2d<T>& point) const
00169 {
00170 vector2d<T> c = point - start;
00171 vector2d<T> v = end - start;
00172 T d = (T)v.getLength();
00173 v /= d;
00174 T t = v.dotProduct(c);
00175
00176 if (t < (T)0.0) return start;
00177 if (t > d) return end;
00178
00179 v *= t;
00180 return start + v;
00181 }
00182
00184 vector2d<T> start;
00186 vector2d<T> end;
00187 };
00188
00190 typedef line2d<f32> line2df;
00192 typedef line2d<s32> line2di;
00193
00194 }
00195 }
00196
00197 #endif
00198