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-rw-r--r-- | dev/MinGfx/src/point2.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/dev/MinGfx/src/point2.h b/dev/MinGfx/src/point2.h new file mode 100644 index 0000000..954f313 --- /dev/null +++ b/dev/MinGfx/src/point2.h @@ -0,0 +1,112 @@ +/* + This file is part of the MinGfx Project. + + Copyright (c) 2017,2018 Regents of the University of Minnesota. + All Rights Reserved. + + Original Author(s) of this File: + Dan Keefe, 2018, University of Minnesota + + Author(s) of Significant Updates/Modifications to the File: + ... + */ + +#ifndef SRC_POINT2_H_ +#define SRC_POINT2_H_ + +#include <iostream> + +namespace mingfx { + +/// Epsilon value used for == and != comparisons within MinGfx +#define MINGFX_MATH_EPSILON 1e-8 + + +/** A 2D Point with floating point coordinates, used for storing 2D texture + coordinates, screen-space graphics, and mouse input. + */ +class Point2 { +public: + /// Default point at the origin + Point2(); + + /// Constructs a point given (x,y,1), where the 1 comes from the use of + /// homogeneous coordinates in computer graphics. + Point2(float x, float y); + + /// Constructs a point given a pointer to x,y data + Point2(float *p); + + /// Copy constructor for point + Point2(const Point2& p); + + /// Point destructor + virtual ~Point2(); + + /// Check for "equality", taking floating point imprecision into account + bool operator==(const Point2& p) const; + + /// Check for "inequality", taking floating point imprecision into account + bool operator!=(const Point2& p) const; + + /// Assignment operator + Point2& operator=(const Point2& p); + + /// Read only access to the ith coordinate of the point. + float operator[](const int i) const; + + /// Returns a reference to the ith coordinate of the point. Use this + /// accessor if you wish to set the coordinate rather than just request + /// its value. Example: + /// ~~~ + /// Point2 a; + /// a[0] = 5.0; // set the x-coordinate of the point + /// ~~~ + float& operator[](const int i); + + /// Read only access to the x coordinate. Can also use my_point[0]. Use + /// the my_point[0] = 1.0; form if you need to set the value. + float x() const { return p[0]; } + + /// Read only access to the y coordinate. Can also use my_point[1]. Use + /// the my_point[1] = 1.0; form if you need to set the value. + float y() const { return p[1]; } + + /// In homogeneous coordinates, the w coordinate for all points is 1.0. + float w() const { return 1.0; } + + + /// Returns a const pointer to the raw data array + const float * value_ptr() const; + + /// Linear interpolation between this point and another. Alpha=0.0 returns + /// this point, and alpha=1.0 returns the other point, other values blend + /// between the two. + Point2 Lerp(const Point2 &b, float alpha) const; + + + /// (0,0) - a shortcut for a special point that is frequently needed + static const Point2& Origin(); + + /// (0,0) - a shortcut for a special point that is frequently needed + static const Point2& Zero(); + + /// (1,1) - a shortcut for a special point that is frequently needed + static const Point2& One(); + + /// Linear interpolation between two points. Alpha=0.0 returns 'a' and + /// alpha=1.0 returns 'b', other values blend between the two. + static Point2 Lerp(const Point2 &a, const Point2 &b, float alpha); + +private: + float p[2]; +}; + + +std::ostream & operator<< ( std::ostream &os, const Point2 &p); +std::istream & operator>> ( std::istream &is, Point2 &p); + + +} // namespace + +#endif |