Operator '!' is supposed to be true when an angle is 'no rotation'. It was failing...

[synfig.git] / ETL / trunk / ETL / _angle.h

diff --git a/ETL/trunk/ETL/_angle.h b/ETL/trunk/ETL/_angle.h
index df69027..bd3231a 100644 (file)
--- a/ETL/trunk/ETL/_angle.h
+++ b/ETL/trunk/ETL/_angle.h
@@ -1,7 +1,8 @@
+#include <stdio.h>
 /* ========================================================================
 ** Extended Template and Library
 ** Angle Abstraction Class Implementation
-** $Id: _angle.h,v 1.1.1.1 2005/01/04 01:31:46 darco Exp $
+** $Id$
 **
 ** Copyright (c) 2002 Robert B. Quattlebaum Jr.
 **
@@ -59,52 +60,52 @@ public:
 protected:
        typedef value_type unit;
 
-       unit v; //! Stored in rotations
-       
+       unit v; //! Stored in radians; positive values indicate counter-clockwise.
+
 public:
-       
+
        /*
        ** Arithmetic Operators
        */
 
        const angle     &
        operator+=(const angle &rhs)
-               { v+=rhs.v; return *this; }
+       { v+=rhs.v; return *this; }
 
        const angle     &
        operator-=(const angle &rhs)
-               { v-=rhs.v; return *this; }
+       { v-=rhs.v; return *this; }
 
        const angle     &
        operator*=(const unit &rhs)
-               { v*=rhs; return *this; }
+       { v*=rhs; return *this; }
 
        const angle     &
        operator/=(const unit &rhs)
-               { v/=rhs; return *this; }
+       { v/=rhs; return *this; }
 
        //! Angle Addition Operator
        angle
        operator+(const angle &rhs)const
-               { return angle(*this)+=rhs; }
+       { return angle(*this)+=rhs; }
 
        //! Angle Subtraction Operator
        /*! \sa angle dist(const angle &) */
        angle
        operator-(const angle &rhs)const
-               { return angle(*this)-=rhs; }
+       { return angle(*this)-=rhs; }
 
        //! Angle Scalar Multiplication Operator
        /*! This operator will multiply the given
                angle by the given scalar value. */
        angle
        operator*(const unit &rhs)const
-               { return angle(*this)*=rhs; }
+       { return angle(*this)*=rhs; }
 
        angle
        operator/(const unit &rhs)const
-               { return angle(*this)/=rhs; }
-       
+       { return angle(*this)/=rhs; }
+
        //! Angle Negation
        angle
        operator-()const
@@ -113,7 +114,7 @@ public:
                ret.v=-v;
                return ret;
        }
-       
+
        //! 180 degree rotation operator
        /*! Returns the angle directly opposite of
                the given angle, and will yield a result
@@ -122,61 +123,55 @@ public:
        operator~()const
        {
                angle ret;
-               ret.v=(value_type)std::floor(v+0.5f);
-               return ret;
+               ret.v = v+PI;
+               return ret.mod();
        }
 
        /*! Returns true if the shortest
-               angle between the left-hand and
-               right-hand side is clockwise */
+               angle from the left-hand to the
+               right-hand side is counter-clockwise */
        bool
        operator<(const angle &rhs)const
-       { return v<rhs.v; }
-//     { return dist(rhs).v<(value_type)0.0; }
+       { return dist(rhs).v<(value_type)0.0; }
 
        /*! Returns true if the shortest
-               angle between the left-hand and
-               right-hand side is counter-clockwise */
+               angle from the left-hand to the
+               right-hand side is clockwise */
        bool
        operator>(const angle &rhs)const
-       { return v>rhs.v; }
-//     { return dist(rhs).v>(value_type)0.0; }
+       { return dist(rhs).v>(value_type)0.0; }
 
        /*! Returns true if the shortest
-               angle between the left-hand and
-               right-hand side is clockwise,
+               angle from the left-hand to the
+               right-hand side is counter-clockwise,
                or if the angles are refer to the same
                point on the unit circle. */
        bool
        operator<=(const angle &rhs)const
-       { return v<=rhs.v; }
-//     { return dist(rhs).v<=(value_type)0.0; }
+       { return dist(rhs).v<=(value_type)0.0; }
 
        /*! Returns true if the shortest
-               angle between the left-hand and
-               right-hand side is counter-clockwise,
+               angle from the left-hand to the
+               right-hand side is clockwise,
                or if the angles are refer to the same
                point on the unit circle. */
        bool
        operator>=(const angle &rhs)const
-       { return v>=rhs.v; }
-//     { return dist(rhs).v>=(value_type)0.0; }
+       { return dist(rhs).v>=(value_type)0.0; }
 
        /*! Returns true if the angles
                are refer to the same point
                on the unit circle. */
        bool
        operator==(const angle &rhs)const
-       { return v==rhs.v; }
-//     { return dist(rhs).v==(value_type)0.0; }
+       { return std::abs(dist(rhs).v)<epsilon; }
 
        /*! Returns false if the angles
                are refer to the same point
                on the unit circle. */
        bool
        operator!=(const angle &rhs)const
-       { return v!=rhs.v; }
-//     { return dist(rhs).v!=(value_type)0.0; }
+       { return std::abs(dist(rhs).v)>epsilon; }
 
        //! Angle Difference Function
        /*! This function will return the
@@ -187,11 +182,8 @@ public:
        dist(const angle &rhs)const
        {
                angle ret;
-
                ret.v=v-rhs.v;
-               
                ret.v-=rot_floor(ret.v+PI);
-               
                return ret;
        }
 
@@ -205,7 +197,8 @@ public:
                ret.v-=rot_floor(ret.v);
                return ret;
        }
-       
+
+       //! Zero Rotation (0 degrees)
        static angle
        zero()
        {
@@ -214,32 +207,36 @@ public:
                return ret;
        }
 
+       //! One Complete Rotation (360 degrees)
        static angle
        one()
        {
                angle ret;
-               ret.v=PI;
+               ret.v=PI*2;
                return ret;
        }
 
+       //! One Half Rotation (180 degrees)
        static angle
        half()
        {
                angle ret;
-               ret.v=PI*0.5;
+               ret.v=PI;
                return ret;
        }
 
-       bool operator!()const { return v==0; }
+       bool operator!()const { return std::abs(mod().v) < epsilon; }
 
 private:
-       
+
        static value_type rot_floor(value_type x)
        { return static_cast<value_type>(std::floor(x/(PI*2))*PI*2); }
-       
+
+       static const value_type epsilon = 1.0e-6;
+
 public:
        /*
-       ** Converstion Classes
+       ** Conversion Classes
        */
 
        class rad;
@@ -247,12 +244,12 @@ public:
        class rot;
 
        /*
-       ** Trigometric Classes
+       ** Trigonometric Classes
        */
 
        class sin;
        class cos;
-       class tan; 
+       class tan;
 
        /*
        ** Friend classes
@@ -408,7 +405,7 @@ struct affine_combo<etl::angle, T>
 
        //affine_combo() { std::cerr<<"affine_combo<etl::angle,float>: I was created!"<<std::endl; }
        //~affine_combo() { std::cerr<<"affine_combo<etl::angle,float>: I was DELETED!"<<std::endl; }
-       
+
        etl::angle operator()(const etl::angle &a,const etl::angle &b,const time_type &t)const
        {
                return b.dist(a)*(float)t+a;
@@ -430,12 +427,11 @@ struct distance_func<etl::angle> : public std::binary_function<etl::angle, etl::
                //      return delta+etl::angle::one();
                return delta;
        }
-       
+
        etl::angle cook(const etl::angle &x)const { return x; }
        etl::angle uncook(const etl::angle &x)const { return x; }
 };
 
-
 /* === E N D =============================================================== */
 
 #endif