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00002
00003
00004
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 = (f32)((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 = (f32)((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 = (f32)((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
00092 if(equals(numeratorA, 0.f) && equals(numeratorB, 0.f))
00093 {
00094
00095 if(l.start == start || l.end == start)
00096 out = start;
00097 else if(l.end == end || l.start == end)
00098 out = end;
00099
00100 else if (l.start.X>start.X && l.end.X>start.X && l.start.X>end.X && l.end.X>end.X)
00101 return false;
00102 else if (l.start.Y>start.Y && l.end.Y>start.Y && l.start.Y>end.Y && l.end.Y>end.Y)
00103 return false;
00104 else if (l.start.X<start.X && l.end.X<start.X && l.start.X<end.X && l.end.X<end.X)
00105 return false;
00106 else if (l.start.Y<start.Y && l.end.Y<start.Y && l.start.Y<end.Y && l.end.Y<end.Y)
00107 return false;
00108
00109 else
00110 {
00111
00112
00113 vector2d<T> maxp;
00114 vector2d<T> minp;
00115 if ((start.X>l.start.X && start.X>l.end.X && start.X>end.X) || (start.Y>l.start.Y && start.Y>l.end.Y && start.Y>end.Y))
00116 maxp=start;
00117 else if ((end.X>l.start.X && end.X>l.end.X && end.X>start.X) || (end.Y>l.start.Y && end.Y>l.end.Y && end.Y>start.Y))
00118 maxp=end;
00119 else if ((l.start.X>start.X && l.start.X>l.end.X && l.start.X>end.X) || (l.start.Y>start.Y && l.start.Y>l.end.Y && l.start.Y>end.Y))
00120 maxp=l.start;
00121 else
00122 maxp=l.end;
00123 if (maxp != start && ((start.X<l.start.X && start.X<l.end.X && start.X<end.X) || (start.Y<l.start.Y && start.Y<l.end.Y && start.Y<end.Y)))
00124 minp=start;
00125 else if (maxp != end && ((end.X<l.start.X && end.X<l.end.X && end.X<start.X) || (end.Y<l.start.Y && end.Y<l.end.Y && end.Y<start.Y)))
00126 minp=end;
00127 else if (maxp != l.start && ((l.start.X<start.X && l.start.X<l.end.X && l.start.X<end.X) || (l.start.Y<start.Y && l.start.Y<l.end.Y && l.start.Y<end.Y)))
00128 minp=l.start;
00129 else
00130 minp=l.end;
00131
00132
00133
00134 out = core::vector2d<T>();
00135 if (start != maxp && start != minp)
00136 out += start;
00137 if (end != maxp && end != minp)
00138 out += end;
00139 if (l.start != maxp && l.start != minp)
00140 out += l.start;
00141 if (l.end != maxp && l.end != minp)
00142 out += l.end;
00143 out.X = (T)(out.X*0.5f);
00144 out.Y = (T)(out.Y*0.5f);
00145 }
00146
00147 return true;
00148 }
00149
00150 return false;
00151 }
00152
00153
00154
00155 const f32 uA = numeratorA / commonDenominator;
00156 if(uA < 0.f || uA > 1.f)
00157 return false;
00158
00159 const f32 uB = numeratorB / commonDenominator;
00160 if(uB < 0.f || uB > 1.f)
00161 return false;
00162
00163
00164 out.X = (T)(start.X + uA * (end.X - start.X));
00165 out.Y = (T)(start.Y + uA * (end.Y - start.Y));
00166 return true;
00167 }
00168
00170
00171 vector2d<T> getUnitVector() const
00172 {
00173 T len = (T)(1.0 / getLength());
00174 return vector2d<T>((end.X - start.X) * len, (end.Y - start.Y) * len);
00175 }
00176
00178
00180 f64 getAngleWith(const line2d<T>& l) const
00181 {
00182 vector2d<T> vect = getVector();
00183 vector2d<T> vect2 = l.getVector();
00184 return vect.getAngleWith(vect2);
00185 }
00186
00188
00190 T getPointOrientation(const vector2d<T>& point) const
00191 {
00192 return ( (end.X - start.X) * (point.Y - start.Y) -
00193 (point.X - start.X) * (end.Y - start.Y) );
00194 }
00195
00197
00198 bool isPointOnLine(const vector2d<T>& point) const
00199 {
00200 T d = getPointOrientation(point);
00201 return (d == 0 && point.isBetweenPoints(start, end));
00202 }
00203
00205
00206 bool isPointBetweenStartAndEnd(const vector2d<T>& point) const
00207 {
00208 return point.isBetweenPoints(start, end);
00209 }
00210
00212 vector2d<T> getClosestPoint(const vector2d<T>& point) const
00213 {
00214 vector2d<T> c = point - start;
00215 vector2d<T> v = end - start;
00216 T d = (T)v.getLength();
00217 v /= d;
00218 T t = v.dotProduct(c);
00219
00220 if (t < (T)0.0) return start;
00221 if (t > d) return end;
00222
00223 v *= t;
00224 return start + v;
00225 }
00226
00228 vector2d<T> start;
00230 vector2d<T> end;
00231 };
00232
00234 typedef line2d<f32> line2df;
00236 typedef line2d<s32> line2di;
00237
00238 }
00239 }
00240
00241 #endif
00242