-
Notifications
You must be signed in to change notification settings - Fork 4
/
m_fixed.pas
130 lines (103 loc) · 2.79 KB
/
m_fixed.pas
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
// ------------------------------------------------------------------------------
// DelphiQuake, Copyright (C) 2005-2011 by Jim Valavanis
// E-Mail: jimmyvalavanis@yahoo.gr
//
// Copyright (C) 1996-1997 Id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
//
// See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// ------------------------------------------------------------------------------
{$I dquake.inc}
unit m_fixed;
interface
//-----------------------------------------------------------------------------
//
// Fixed point, 32bit as 16.16.
//
const
FRACBITS = 16;
FRACUNIT = 1 shl FRACBITS;
type
fixed_t = integer;
Pfixed_t = ^fixed_t;
fixed_tArray = packed array[0..$FFFF] of fixed_t;
Pfixed_tArray = ^fixed_tArray;
function FixedMul(const a, b: fixed_t): fixed_t;
function FixedMul88(const a, b: fixed_t): fixed_t;
function FixedMul8(const a, b: fixed_t): fixed_t;
function FixedIntMul(const a, b: fixed_t): fixed_t;
function IntFixedMul(const a, b: fixed_t): fixed_t;
function FixedDiv(const a, b: fixed_t): fixed_t;
function FixedDiv2(const a, b: fixed_t): fixed_t;
function FixedInt(const x: integer): integer;
implementation
uses
q_delphi;
function FixedMul(const a, b: fixed_t): fixed_t; assembler;
asm
imul b
shrd eax, edx, 16
end;
function FixedMul88(const a, b: fixed_t): fixed_t; assembler;
asm
sar a, 8
sar b, 8
imul b
shrd eax, edx, 16
end;
function FixedMul8(const a, b: fixed_t): fixed_t; assembler;
asm
sar a, 8
imul b
shrd eax, edx, 16
end;
function FixedIntMul(const a, b: fixed_t): fixed_t; assembler;
asm
sar b, FRACBITS
imul b
shrd eax, edx, 16
end;
function IntFixedMul(const a, b: fixed_t): fixed_t; assembler;
asm
sar eax, FRACBITS
imul b
shrd eax, edx, 16
end;
function FixedDiv(const a, b: fixed_t): fixed_t;
begin
if _SHR14(abs(a)) >= abs(b) then
begin
if a xor b < 0 then
result := MININT
else
result := MAXINT;
end
else
result := FixedDiv2(a, b);
end;
function FixedDiv2(const a, b: fixed_t): fixed_t; assembler;
asm
mov ebx, b
mov edx, eax
sal eax, 16
sar edx, 16
idiv ebx
end;
function FixedInt(const x: integer): integer; assembler;
asm
sar eax, FRACBITS
end;
end.