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30 #include "wtf/text/StringBuilder.h"
35 // Class representing a closed interval which can hold an arbitrary
36 // Plain Old Datatype (POD) as its endpoints and a piece of user
37 // data. An important characteristic for the algorithms we use is that
38 // if two intervals have identical endpoints but different user data,
39 // they are not considered to be equal. This situation can arise when
40 // representing the vertical extents of bounding boxes of overlapping
41 // triangles, where the pointer to the triangle is the user data of
44 // *Note* that the destructors of type T and UserData will *not* be
45 // called by this class. They must not allocate any memory that is
46 // required to be cleaned up in their destructors.
48 // The following constructors and operators must be implemented on
51 // - Copy constructor (if user data is desired)
56 // If the UserData type is specified, it must support a copy
57 // constructor and assignment operator.
59 // In debug mode, printing of intervals and the data they contain is
60 // enabled. This requires the following template specializations to be
63 // template<> struct ValueToString<T> {
64 // static String string(const T& t);
66 // template<> struct ValueToString<UserData> {
67 // static String string(const UserData& t);
70 // Note that this class requires a copy constructor and assignment
71 // operator in order to be stored in the red-black tree.
78 template<class T, class UserData = void*>
81 // Constructor from endpoints. This constructor only works when the
82 // UserData type is a pointer or other type which can be initialized
84 PODInterval(const T& low, const T& high)
92 // Constructor from two endpoints plus explicit user data.
93 PODInterval(const T& low, const T& high, const UserData data)
101 const T& low() const { return m_low; }
102 const T& high() const { return m_high; }
103 const UserData& data() const { return m_data; }
105 bool overlaps(const T& low, const T& high) const
107 if (this->high() < low)
109 if (high < this->low())
114 bool overlaps(const PODInterval& other) const
116 return overlaps(other.low(), other.high());
119 // Returns true if this interval is "less" than the other. The
120 // comparison is performed on the low endpoints of the intervals.
121 bool operator<(const PODInterval& other) const
123 return low() < other.low();
126 // Returns true if this interval is strictly equal to the other,
127 // including comparison of the user data.
128 bool operator==(const PODInterval& other) const
130 return (low() == other.low() && high() == other.high() && data() == other.data());
133 const T& maxHigh() const { return m_maxHigh; }
134 void setMaxHigh(const T& maxHigh) { m_maxHigh = maxHigh; }
137 // Support for printing PODIntervals.
138 String toString() const
140 StringBuilder builder;
141 builder.appendLiteral("[PODInterval (");
142 builder.append(ValueToString<T>::string(low()));
143 builder.appendLiteral(", ");
144 builder.append(ValueToString<T>::string(high()));
145 builder.appendLiteral("), data=");
146 builder.append(ValueToString<UserData>::string(data()));
147 builder.appendLiteral(", maxHigh=");
148 builder.append(ValueToString<T>::string(maxHigh()));
150 return builder.toString();
163 #endif // PODInterval_h