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
|
/*
This file is part of the Boson game
Copyright (C) 2002-2005 Rivo Laks (rivolaks@hot.ee)
Copyright (C) 2002-2005 Andreas Beckermann (b_mann@gmx.de)
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "math/bo3dtoolsbase.h"
#include <math.h>
#include <stdio.h>
// Degrees to radians conversion (AB: from mesa/src/macros.h)
#define DEG2RAD (M_PI/180.0)
// And radians to degrees conversion
#define RAD2DEG (180.0/M_PI)
bofixed Bo3dToolsBase::rotationToPoint(bofixed x, bofixed y)
{
bofixed add = 0;
bofixed arg = 0;
if(x > 0)
{
if(y < 0)
{
add = 0;
arg = x / -y;
}
else
{
add = 90;
arg = y / x;
}
}
else
{
if(y > 0)
{
add = 180;
arg = -x / y;
}
else if(x < 0)
{
add = 270;
arg = -y / -x;
}
else
{
return 0;
}
}
return (atan(arg) * RAD2DEG) + add;
}
void Bo3dToolsBase::pointByRotation(bofixed* x, bofixed* y, const bofixed& angle, const bofixed& radius)
{
// Some quick tests
if(angle == 0)
{
*x = 0;
*y = -radius;
return;
}
else if(angle == 90)
{
*x = radius;
*y = 0;
return;
}
else if(angle == 180)
{
*x = 0;
*y = radius;
return;
}
else if(angle == 270)
{
*x = -radius;
*y = 0;
return;
}
// AB: WARNING: to avoid overflows in bofixed (max value around 16383) we use
// float here.
float tmpx = tanf(angle / RAD2DEG);
float tmpy = 1;
float length = sqrtf(tmpx * tmpx + tmpy * tmpy);
tmpx = tmpx / length * radius;
tmpy = tmpy / length * radius;
if(angle < 90)
{
*x = tmpx;
*y = -tmpy;
}
else if(angle < 180)
{
*x = -tmpx;
*y = tmpy;
}
else if(angle < 270)
{
*x = -tmpx;
*y = tmpy;
}
else
{
*x = tmpx;
*y = -tmpy;
}
}
void Bo3dToolsBase::pointByRotation(float* _x, float* _y, const float _angle, const float _radius)
{
// AB: we use a bofixed implementation by default.
// the float one lacks some precision because of that, but I believe that
// doesn't hurt.
// if that precision is required, we need to implement this method twice, but
// we must not use a float implementation, because of network stability
// (floating point operations can have different results on differenct
// computers)
bofixed x, y;
bofixed angle(_angle);
bofixed radius(_radius);
pointByRotation(&x, &y, angle, radius);
*_x = x;
*_y = y;
}
/*
* vim:et sw=2
*/
|
