fixed16.h

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// $Id: fixed16.h 1261 2006-06-06 11:58:26Z alex $
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 */

class StringBase;

/*
 */ 

/*********************************************************************************************

>   class FIXED16

    Author:     Mario_Shamtani (Xara Group Ltd) <camelotdev@xara.com>
    Created:    26/4/1993
    SeeAlso:    CCMaths.h
    SeeAlso:    Fixedasm.h
    SeeAlso:    Div32By32
    SeeAlso:    Keyword FIXED16
    Purpose:    
        An FIXED16 is a signed 32-bit value with a binary point between bits 15 and 16. 
        Its purpose is to represent 32-bit floating point numbers.
        FIXED16 is a fixed point number contained within a 32-bit longword.
        The high 16-bit half contains the integer part, the low half the fractional. (Intel
        implementations store this as the low half first in memory). The integer half ranges
        from -32768 to 32767, the fractional part from 0 to 65535/65536ths (1/65536th=
        0.000015259, 65535/65536=0.999984741). For efficiency all primitives are written
        in assembly-language, though most are used transparently by operator overloading.
        No-one should include fixed16.h directly - always use ccmath.h. You should also
        never use the lower-case type 'fixed16' - always used 'FIXED16'.    
    Errors:     None.
    
********************************************************************************************/

#ifndef INC_FIXED16
#define INC_FIXED16

// One as a fixed16 as a longword, and 0.5 as...
const INT32 FIXED16_ONE = 0x10000L;
const INT32 FIXED16_HALF= 0x08000L;

#if !defined(USE_NATIVE_XLONG)
class CCAPI xlong;
#endif

class CCAPI String;

class CCAPI fixed16
{
public:
    INT32 all;



public:

    #define F16SHIFT 16                                 // marks binary point position

    // this converts a short into a fixed16 longword by casting to an INT32 then shifting it
    #define SHORT_FIXED(x)  ( ((INT32)(x)) << F16SHIFT )

    inline fixed16() {};                
    inline fixed16(const fixed16&);
    inline fixed16(INT32);
    inline fixed16(short);
    inline fixed16(double);

    fixed16& Sin();
    fixed16& Cos();

    inline fixed16 trunc() const;
    inline fixed16 round() const;
    inline fixed16 abs() const;
    inline fixed16 sgn() const;
    
    void ToString(StringBase* out) const;

    // Friend Functions

    inline friend fixed16 Div32By32(const INT32 a, const INT32 b);
    inline friend fixed16 CCAPI operator+ (const fixed16&, const fixed16&);
    inline friend fixed16 CCAPI operator- (const fixed16&, const fixed16&);
    inline friend fixed16 CCAPI operator- (const fixed16&);
    inline friend fixed16 CCAPI operator* (const fixed16&, const fixed16&);
    inline friend fixed16 CCAPI operator/ (const fixed16&, const fixed16&);
    inline friend fixed16 CCAPI operator>> (const fixed16&, UINT32);
    inline friend fixed16 CCAPI operator<< (const fixed16&, UINT32);

    // Relational Operators
    
    inline friend INT32 CCAPI operator== (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator== (const fixed16&, const short);
    inline friend INT32 CCAPI operator!= (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator!= (const fixed16&, const short);
    inline friend INT32 CCAPI operator> (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator> (const fixed16&, const short);
    inline friend INT32 CCAPI operator< (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator< (const fixed16&, const short);
    inline friend INT32 CCAPI operator>= (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator>= (const fixed16&, const short);
    inline friend INT32 CCAPI operator<= (const fixed16&, const fixed16&);
    inline friend INT32 CCAPI operator<= (const fixed16&, const short);
    
    // Assignment Operators

    inline fixed16& operator= (const fixed16&);
    inline fixed16& operator= (const INT32);
    inline fixed16& operator= (const short);
    inline fixed16& operator= (const double);
    inline fixed16& operator+= (const fixed16&);
    inline fixed16& operator+= (const short);
    inline fixed16& operator-= (const fixed16&); 
    inline fixed16& operator-= (const short);
    inline fixed16& operator*= (const fixed16&); 
    inline fixed16& operator*= (const short);
    inline fixed16& operator/= (const fixed16&);
    inline fixed16& operator/= (const short); 
    inline fixed16& operator<<= (const UINT32); 
    inline fixed16& operator>>= (const UINT32); 

    // Increment\Decrement Operators

    inline fixed16& operator++ ();                          // prefix
    inline fixed16 operator++ (INT32);                      // postfix 
    inline fixed16& operator-- ();                          // prefix 
    inline fixed16 operator-- (INT32);                      // postfix 

    // Conversion functions

    inline INT32     MakeInt() const;
    inline short MakeShort() const;
    inline double MakeDouble() const;
    inline INT32  MakeLong() const;
    inline xlong MakeXlong() const;

    inline static fixed16 FromRawLong(INT32 d);
    inline static fixed16 FromShifted16(INT32 d);
    inline INT32 GetRawLong() const;
    inline INT32 GetShifted16() const;
};


// this is a temporary kludge for the 32-bit MS compiler
#define F16ASSIGN( it )     it
#define F16ASSIGNTHIS       *this

#include "fixed.h"

/********************************************************************************************

Note that all the comment blocks live in the cpp files so they get compiled in with the help
compiler

********************************************************************************************/

#define FIXED16_DBL(d) fixed16::FromRawLong((INT32)((d)*65536))

inline fixed16::fixed16(const fixed16& initValue) 
{
    all = initValue.all;
}

inline fixed16::fixed16(INT32 initValue) 
{
    all = SHORT_FIXED( initValue );
}

inline fixed16::fixed16(short initValue) 
{
    all = SHORT_FIXED( initValue );
}

inline fixed16::fixed16(double initValue) 
{
    *this = DoubleToFixed16(initValue);
}

inline fixed16 fixed16::FromRawLong(INT32 d)
{
    fixed16 temp;
    temp.all = d;
    return temp;
}

inline fixed16 fixed16::FromShifted16(INT32 d)
{
    fixed16 temp;
    temp.all = d;
    return temp;
}

inline INT32 fixed16::MakeInt() const
{
    return (INT32) (all >> F16SHIFT);
}

inline short fixed16::MakeShort() const
{
    return (short) (all >> F16SHIFT);
}

inline INT32 fixed16::MakeLong() const
{
    return all >> F16SHIFT;
}

inline xlong fixed16::MakeXlong() const
{
    return xlong( (short) (all >> F16SHIFT) );
}


inline fixed16& fixed16::operator= (const fixed16& operand)
{ 
    this->all = operand.all;
    
    return *this; 
}

inline double fixed16::MakeDouble() const
{
    return Fixed16ToDouble(*this);
}

inline fixed16& fixed16::operator= (const short operand)
{ 
    this->all = SHORT_FIXED( operand );
    return *this;
}

inline INT32 fixed16::GetRawLong() const
{
    return this->all;
}

inline INT32 fixed16::GetShifted16() const
{
    return this->all;
}

inline fixed16 fixed16::trunc() const
{
    return FromRawLong( all & 0xFFFF0000L );
}
    
inline fixed16 fixed16::round() const
{
    return FromRawLong( ( all + FIXED16_HALF ) & 0xFFFF0000L );
}
    
inline fixed16 fixed16::abs() const
{
    return FromRawLong( all<0 ? -all : all );
}
    
inline fixed16 fixed16::sgn() const
{
    return FromRawLong( all<0 ? -FIXED16_ONE : FIXED16_ONE );
}
    
inline fixed16 operator+ (const fixed16& operand1, const fixed16& operand2)
{
    fixed16 result;
    result.all = operand1.all + operand2.all;
    return result;
}

inline fixed16 operator- (const fixed16& operand1, const fixed16& operand2)
{
    fixed16 result;
    result.all = operand1.all - operand2.all;
    return result;
}

inline fixed16 operator- (const fixed16& operand)
{
    fixed16 temp;
    temp.all = -operand.all;
    return temp;
}

inline fixed16 operator* (const fixed16& operand1, const fixed16& operand2)
{
    fixed16 result;
    F16ASSIGN(result) = Fixed16Mul( operand1, operand2 );
    return result;
}

inline fixed16 operator/ (const fixed16& operand1, const fixed16& operand2)
{
    fixed16 result;
    F16ASSIGN(result) = Fixed16Div( operand1, operand2 );
    return result;
}

inline fixed16 operator>> (const fixed16& operand1, UINT32 operand2)
{
    fixed16 result;
    result.all = operand1.all >> operand2;
    return result;
}

inline fixed16 operator<< (const fixed16& operand1, UINT32 operand2)
{
    fixed16 result;
    
    result.all = operand1.all << operand2;
    
    return result;
}

inline INT32 operator== (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all == operand2.all;
}

inline INT32 operator== (const fixed16& operand1, const short operand2) 
{
    return operand1.all == SHORT_FIXED( operand2 );
}

inline INT32 operator!= (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all != operand2.all;
}

inline INT32 operator!= (const fixed16& operand1, const short operand2) 
{
    return operand1.all != SHORT_FIXED( operand2 );
}

inline INT32 operator> (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all > operand2.all;
}

inline INT32 operator> (const fixed16& operand1, const short operand2) 
{
    return operand1.all > SHORT_FIXED(operand2);
}

inline INT32 operator< (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all < operand2.all;
}

inline INT32 operator< (const fixed16& operand1, const short operand2) 
{
    return operand1.all < SHORT_FIXED( operand2 );
}

inline INT32 operator>= (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all >= operand2.all;
}

inline INT32 operator>= (const fixed16& operand1, const short operand2) 
{
    return operand1.all >= SHORT_FIXED( operand2 );
}

inline INT32 operator<= (const fixed16& operand1, const fixed16& operand2) 
{
    return operand1.all <= operand2.all;
}

inline INT32 operator<= (const fixed16& operand1, const short operand2) 
{
    return operand1.all <= SHORT_FIXED( operand2 );
}

inline fixed16& fixed16::operator= (const INT32 operand)
{
    this->all = SHORT_FIXED( operand );
    return *this;
}

inline fixed16& fixed16::operator= (const double operand)
{ 
    F16ASSIGNTHIS = DoubleToFixed16(operand);
    return *this;
}

inline fixed16& fixed16::operator+= (const fixed16& operand)
{ 
    this->all += operand.all;
    return *this;
}

inline fixed16& fixed16::operator+= (const short operand)
{ 
    this->all += SHORT_FIXED( operand );
    return *this;
}

inline fixed16& fixed16::operator-= (const fixed16& operand)
{
    this->all -= operand.all;
    return *this;
}

inline fixed16& fixed16::operator-= (const short operand)
{
    this->all -= SHORT_FIXED( operand );
    return *this;
}

inline fixed16& fixed16::operator*= (const fixed16& operand)
{
    F16ASSIGNTHIS = Fixed16Mul(*this, operand);
    
    return *this;
}

inline fixed16& fixed16::operator*= (const short operand)
{                                  
    fixed16 temp;
    
    temp.all = SHORT_FIXED( operand );
    
    F16ASSIGNTHIS = Fixed16Mul(*this, temp);
    
    return *this;
}

inline fixed16& fixed16::operator/= (const fixed16& operand)
{
    F16ASSIGNTHIS = Fixed16Div(*this, operand);
    
    return *this;
}

inline fixed16& fixed16::operator/= (const short operand)
{
    fixed16 temp;
    
    temp.all = SHORT_FIXED( operand );
    
    F16ASSIGNTHIS = Fixed16Div(*this, temp);
    
    return *this;
}

inline fixed16& fixed16::operator<<= (const UINT32 operand)
{
    this->all <<= operand;
    return *this;
}
  
inline fixed16& fixed16::operator>>= (const UINT32 operand)
{
    this->all >>= operand;
    return *this;
} 

inline fixed16& fixed16::operator++ ()                          // prefix
{
    this->all += FIXED16_ONE;
    return *this;
}

inline fixed16 fixed16::operator++ (INT32 dummy)                // postfix 
{                
    fixed16 result = *this;
    
    this->all += FIXED16_ONE;
    
    return result;
}

inline fixed16& fixed16::operator-- ()                          // prefix 
{
    this->all -= FIXED16_ONE;
    return *this;
}

inline fixed16 fixed16::operator-- (INT32 dummy)                // postfix 
{
    fixed16 result = *this;
    
    this->all -= FIXED16_ONE;
    
    return result;
}
    
#endif

---