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Diffstat (limited to 'nGenEx/Fix.h')
-rw-r--r-- | nGenEx/Fix.h | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/nGenEx/Fix.h b/nGenEx/Fix.h new file mode 100644 index 0000000..d3aade0 --- /dev/null +++ b/nGenEx/Fix.h @@ -0,0 +1,204 @@ +/* Starshatter OpenSource Distribution + Copyright (c) 1997-2004, Destroyer Studios LLC. + All Rights Reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + * Neither the name "Destroyer Studios" nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. + + SUBSYSTEM: nGenEx.lib + FILE: Fix.h + AUTHOR: John DiCamillo + + + OVERVIEW + ======== + Fixed point number class with 16 bits of fractional precision +*/ + +#ifndef Fix_h +#define Fix_h + +// +--------------------------------------------------------------------+ + +#include "Types.h" + +// +--------------------------------------------------------------------+ + +const double fix_sixty_five=65536.0; + +inline int fast_f2i(double d) +{ + int i; + + _asm { + fld d + fistp i + } + + return i; +} + +// +--------------------------------------------------------------------+ + +class fix +{ +public: + static const char* TYPENAME() { return "fix"; } + + enum FixDef { Precision=16, IntMask=0xffff0000, FractMask=0x0000ffff }; + static const fix one; + static const fix two; + static const fix three; + static const fix five; + static const fix ten; + + fix() { } + fix(int n) : val(n<<Precision) { } + fix(double d) + { + long ival; + _asm { + fld fix_sixty_five + fmul d + fistp ival + } + val=ival; + } + fix(const fix& f) : val(f.val) { } + + // conversion operators: + operator int () const { return (val>>Precision); } + operator float () const { return ((float) val) / ((float) fix_sixty_five); } + operator double() const { return ((double) val) / fix_sixty_five; } + + // assignment operators: + fix& operator=(const fix& f) { val=f.val; return *this; } + fix& operator=(int n) { val=(n<<Precision); return *this; } + fix& operator=(double d) { long ival; + _asm { fld fix_sixty_five + fmul d + fistp ival } + val = ival; + return *this; } + + // comparison operators: + int operator==(const fix& f) const { return val==f.val; } + int operator!=(const fix& f) const { return val!=f.val; } + int operator<=(const fix& f) const { return val<=f.val; } + int operator>=(const fix& f) const { return val>=f.val; } + int operator< (const fix& f) const { return val< f.val; } + int operator> (const fix& f) const { return val> f.val; } + + // arithmetic operators: + fix operator+(const fix& f) const { fix r; r.val = val+f.val; return r; } + fix operator-(const fix& f) const { fix r; r.val = val-f.val; return r; } + fix operator*(const fix& f) const { long a=val; long b=f.val; + _asm { + mov eax, a + mov edx, b + imul edx + shrd eax, edx, 16 + mov a, eax + } + fix r; r.val = a; return r; } + fix operator/(const fix& f) const { long a=val; long b=f.val; + _asm { + mov eax, a + mov ebx, b + mov edx, eax + sar edx, 16 + shl eax, 16 + idiv ebx + mov a, eax + } + fix r; r.val = a; return r; } + fix& operator+=(const fix& f) { val+=f.val; return *this; } + fix& operator-=(const fix& f) { val-=f.val; return *this; } + fix& operator*=(const fix& f) { long a=val; long b=f.val; + _asm { + mov eax, a + mov edx, b + imul edx + shrd eax, edx, 16 + mov a, eax + } + val=a; return *this; } + fix& operator/=(const fix& f) { long a=val; long b=f.val; + _asm { + mov eax, a + mov ebx, b + mov edx, eax + sar edx, 16 + shl eax, 16 + idiv ebx + mov a, eax + } + val=a; return *this; } + + fix operator+(int n) const { fix r; r.val = val+(n<<Precision); return r; } + fix operator-(int n) const { fix r; r.val = val-(n<<Precision); return r; } + fix operator*(int n) const { fix r; r.val = val*n; return r; } + fix operator/(int n) const { fix r; r.val = val/n; return r; } + fix& operator+=(int n) { val+=(n<<Precision); return *this; } + fix& operator-=(int n) { val-=(n<<Precision); return *this; } + fix& operator*=(int n) { val*=n; return *this; } + fix& operator/=(int n) { val/=n; return *this; } + + fix operator+(double d) const { fix f(d); return (*this)+f; } + fix operator-(double d) const { fix f(d); return (*this)-f; } + fix operator*(double d) const { fix f(d); return (*this)*f; } + fix operator/(double d) const { fix f(d); return (*this)/f; } + fix& operator+=(double d) { fix f(d); val+=f.val; return *this; } + fix& operator-=(double d) { fix f(d); val-=f.val; return *this; } + fix& operator*=(double d) { int n; _asm { fld d + fistp n } val*=n; return *this; } + fix& operator/=(double d) { int n; _asm { fld d + fistp n } val/=n; return *this; } + + // misc. functions: + fix truncate() const { fix r; r.val = val&IntMask; return r; } + fix fraction() const { fix r; r.val = val-truncate().val; return r; } + fix floor() const { fix r; r.val = val&IntMask; return r; } + fix ceil() const { fix r; r.val = (val+FractMask)&IntMask; return r; } + fix adjust_up() const { fix r; r.val = val+FractMask; return r; } + fix adjust_down() const { fix r; r.val = val-FractMask; return r; } + + fix muldiv(const fix& num, const fix& den) const + { long a=val, b=num.val, c=den.val; + _asm { + mov eax, a + mov edx, b + mov ebx, c + imul edx + idiv ebx + mov a, eax + } + fix r; r.val = a; return r; } + + // data: + long val; +}; + +#endif Fix_h + |