Diff: Vec2.h

Revision:

0:785cff1e5a7c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Vec2.h	Mon Jan 04 15:19:10 2016 +0000
@@ -0,0 +1,373 @@
+/*
+    File:           Vec2.h
+
+    Function:       Defines a length-2 vector.
+
+    Author(s):      Andrew Willmott
+
+    Copyright:      (c) 1995-2001, Andrew Willmott
+ */
+
+#ifndef __Vec2__
+#define __Vec2__
+#include "Constants.h"
+#include "Basics.h"
+
+// --- Vec2 Class -------------------------------------------------------------
+
+
+class Vec2
+{
+public:
+
+    // Constructors
+
+                Vec2();
+                Vec2(double x, double y);       // (x, y)
+                Vec2(const Vec2 &v);        // Copy constructor
+                Vec2(ZeroOrOne k);          // v[i] = vl_zero
+                Vec2(Axis k);               // v[k] = 1
+
+    // Accessor functions
+
+    double        &operator [] (Int i);
+    const double  &operator [] (Int i) const;
+
+    Int         Elts() const { return(2); };
+    double        *Ref() const;                       // Return ptr to data
+
+    // Assignment operators
+
+    Vec2        &operator =  (const Vec2 &a);
+    Vec2        &operator =  (ZeroOrOne k);
+    Vec2        &operator =  (Axis k);
+
+    Vec2        &operator += (const Vec2 &a);
+    Vec2        &operator -= (const Vec2 &a);
+    Vec2        &operator *= (const Vec2 &a);
+    Vec2        &operator *= (double s);
+    Vec2        &operator /= (const Vec2 &a);
+    Vec2        &operator /= (double s);
+
+    // Comparison operators
+
+    bool        operator == (const Vec2 &a) const;  // v == a?
+    bool        operator != (const Vec2 &a) const;  // v != a?
+
+    // Arithmetic operators
+
+    Vec2        operator + (const Vec2 &a) const;   // v + a
+    Vec2        operator - (const Vec2 &a) const;   // v - a
+    Vec2        operator - () const;                // -v
+    Vec2        operator * (const Vec2 &a) const;   // v * a (vx * ax, ...)
+    Vec2        operator * (double s) const;          // v * s
+    Vec2        operator / (const Vec2 &a) const;   // v / a (vx / ax, ...)
+    Vec2        operator / (double s) const;          // v / s
+
+    // Initialisers
+
+    Vec2        &MakeZero();                        // Zero vector
+    Vec2        &MakeUnit(Int i, double k = vl_one);  // I[i]
+    Vec2        &MakeBlock(double k = vl_one);        // All-k vector
+
+    Vec2        &Normalise();                       // normalise vector
+
+    // Private...
+
+protected:
+
+    double            elt[2];
+};
+
+
+// --- Vec operators ----------------------------------------------------------
+
+inline Vec2     operator * (double s, const Vec2 &v); // s * v
+inline double     dot(const Vec2 &a, const Vec2 &b);  // v . a
+inline double     len(const Vec2 &v);                 // || v ||
+inline double     sqrlen(const Vec2 &v);              // v . v
+inline Vec2     norm(const Vec2 &v);                // v / || v ||
+inline void     normalise(Vec2 &v);                 // v = norm(v)
+inline Vec2     cross(const Vec2 &v);               // cross prod.
+
+//std::ostream &operator << (std::ostream &s, const Vec2 &v);
+//std::istream &operator >> (std::istream &s, Vec2 &v);
+
+inline void printVec2(const Vec2 &v);
+
+
+// --- Inlines ----------------------------------------------------------------
+
+inline double &Vec2::operator [] (Int i)
+{
+    CheckRange(i, 0, 2, "(Vec2::[i]) index out of range");
+    return(elt[i]);
+}
+
+inline const double &Vec2::operator [] (Int i) const
+{
+    CheckRange(i, 0, 2, "(Vec2::[i]) index out of range");
+    return(elt[i]);
+}
+
+inline Vec2::Vec2()
+{
+}
+
+inline Vec2::Vec2(double x, double y)
+{
+    elt[0] = x;
+    elt[1] = y;
+}
+
+inline Vec2::Vec2(const Vec2 &v)
+{
+    elt[0] = v[0];
+    elt[1] = v[1];
+}
+
+inline double *Vec2::Ref() const
+{
+    return((double *) elt);
+}
+
+inline Vec2 &Vec2::operator = (const Vec2 &v)
+{
+    elt[0] = v[0];
+    elt[1] = v[1];
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator += (const Vec2 &v)
+{
+    elt[0] += v[0];
+    elt[1] += v[1];
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator -= (const Vec2 &v)
+{
+    elt[0] -= v[0];
+    elt[1] -= v[1];
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator *= (const Vec2 &v)
+{
+    elt[0] *= v[0];
+    elt[1] *= v[1];
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator *= (double s)
+{
+    elt[0] *= s;
+    elt[1] *= s;
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator /= (const Vec2 &v)
+{
+    elt[0] /= v[0];
+    elt[1] /= v[1];
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator /= (double s)
+{
+    elt[0] /= s;
+    elt[1] /= s;
+
+    return(SELF);
+}
+
+inline Vec2 Vec2::operator + (const Vec2 &a) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] + a[0];
+    result[1] = elt[1] + a[1];
+
+    return(result);
+}
+
+inline Vec2 Vec2::operator - (const Vec2 &a) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] - a[0];
+    result[1] = elt[1] - a[1];
+
+    return(result);
+}
+
+inline Vec2 Vec2::operator - () const
+{
+    Vec2 result;
+
+    result[0] = -elt[0];
+    result[1] = -elt[1];
+
+    return(result);
+}
+
+inline Vec2 Vec2::operator * (const Vec2 &a) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] * a[0];
+    result[1] = elt[1] * a[1];
+
+    return(result);
+}
+
+inline Vec2 Vec2::operator * (double s) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] * s;
+    result[1] = elt[1] * s;
+
+    return(result);
+}
+
+inline Vec2 operator * (double s, const Vec2 &v)
+{
+    return(v * s);
+}
+
+inline Vec2 Vec2::operator / (const Vec2 &a) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] / a[0];
+    result[1] = elt[1] / a[1];
+
+    return(result);
+}
+
+inline Vec2 Vec2::operator / (double s) const
+{
+    Vec2 result;
+
+    result[0] = elt[0] / s;
+    result[1] = elt[1] / s;
+
+    return(result);
+}
+
+inline double dot(const Vec2 &a, const Vec2 &b)
+{
+    return(a[0] * b[0] + a[1] * b[1]);
+}
+
+inline Vec2 cross(const Vec2 &a)
+{
+    Vec2 result;
+
+    result[0] =  a[1];
+    result[1] = -a[0];
+
+    return(result);
+}
+
+inline double len(const Vec2 &v)
+{
+    return(sqrt(dot(v, v)));
+}
+
+inline double sqrlen(const Vec2 &v)
+{
+    return(dot(v, v));
+}
+
+inline Vec2 norm(const Vec2 &v)
+{
+    Assert(sqrlen(v) > 0.0, "normalising length-zero vector");
+    return(v / len(v));
+}
+
+inline void normalise(Vec2 &v)
+{
+    v /= len(v);
+}
+
+inline Vec2 &Vec2::MakeUnit(Int i, double k)
+{
+    if (i == 0)
+    { elt[0] = k; elt[1] = vl_zero; }
+    else if (i == 1)
+    { elt[0] = vl_zero; elt[1] = k; }
+    else
+        _Error("(Vec2::Unit) illegal unit vector");
+    return(SELF);
+}
+
+inline Vec2 &Vec2::MakeZero()
+{
+    elt[0] = vl_zero; elt[1] = vl_zero;
+    return(SELF);
+}
+
+inline Vec2 &Vec2::MakeBlock(double k)
+{
+    elt[0] = k; elt[1] = k;
+    return(SELF);
+}
+
+inline Vec2 &Vec2::Normalise()
+{
+    Assert(sqrlen(SELF) > 0.0, "normalising length-zero vector");
+    SELF /= len(SELF);
+    return(SELF);
+}
+
+
+inline Vec2::Vec2(ZeroOrOne k)
+{
+    elt[0] = k;
+    elt[1] = k;
+}
+
+inline Vec2::Vec2(Axis k)
+{
+    MakeUnit(k, vl_one);
+}
+
+inline Vec2 &Vec2::operator = (ZeroOrOne k)
+{
+    elt[0] = k; elt[1] = k;
+
+    return(SELF);
+}
+
+inline Vec2 &Vec2::operator = (Axis k)
+{
+    MakeUnit(k, vl_1);
+
+    return(SELF);
+}
+
+inline bool Vec2::operator == (const Vec2 &a) const
+{
+    return(elt[0] == a[0] && elt[1] == a[1]);
+}
+
+inline bool Vec2::operator != (const Vec2 &a) const
+{
+    return(elt[0] != a[0] || elt[1] != a[1]);
+}
+
+inline void printVec2(const Vec2 &v)
+{    
+    printf("[%10f %10f]",v[0],v[1]);
+}
+
+
+#endif