summaryrefslogtreecommitdiffhomepage
path: root/nGenEx/Fix.h
blob: ea6687232ae980e4d124c9096695cc2b605369d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*  Project nGenEx
	Destroyer Studios LLC
	Copyright © 1997-2004. All Rights Reserved.

	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