OpenTTD Source: src/direction_func.h Source File

OpenTTD Source 14.0-beta1

direction_func.h
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1 /*
2 * This file is part of OpenTTD.
3 * OpenTTD 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, version 2.
4 * OpenTTD 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.
5 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6 */
7
10 #ifndef DIRECTION_FUNC_H
11 #define DIRECTION_FUNC_H
12
13 #include "direction_type.h"
14
21 inline bool IsValidDiagDirection(DiagDirection d)
22 {
23 return d < DIAGDIR_END;
24 }
25
32 inline bool IsValidDirection(Direction d)
33 {
34 return d < DIR_END;
35 }
36
43 inline bool IsValidAxis(Axis d)
44 {
45 return d < AXIS_END;
46 }
47
54 inline Direction ReverseDir(Direction d)
55 {
56 assert(IsValidDirection(d));
57 return (Direction)(4 ^ d);
58 }
59
60
68 inline DirDiff DirDifference(Direction d0, Direction d1)
69 {
70 assert(IsValidDirection(d0));
71 assert(IsValidDirection(d1));
72 /* Cast to uint so compiler can use bitmask. If the difference is negative
73 * and we used int instead of uint, further "+ 8" would have to be added. */
74 return static_cast<DirDiff>((static_cast<uint>(d0) - static_cast<uint>(d1)) % 8);
75 }
76
88 inline DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
89 {
90 /* Cast to uint so compiler can use bitmask. Result can never be negative. */
91 return static_cast<DirDiff>((static_cast<uint>(d) + static_cast<uint>(delta)) % 8);
92 }
93
104 inline Direction ChangeDir(Direction d, DirDiff delta)
105 {
106 assert(IsValidDirection(d));
107 /* Cast to uint so compiler can use bitmask. Result can never be negative. */
108 return static_cast<Direction>((static_cast<uint>(d) + static_cast<uint>(delta)) % 8);
109 }
110
111
118 inline DiagDirection ReverseDiagDir(DiagDirection d)
119 {
120 assert(IsValidDiagDirection(d));
121 return (DiagDirection)(2 ^ d);
122 }
123
131 inline DiagDirDiff DiagDirDifference(DiagDirection d0, DiagDirection d1)
132 {
133 assert(IsValidDiagDirection(d0));
134 assert(IsValidDiagDirection(d1));
135 /* Cast to uint so compiler can use bitmask. Result can never be negative. */
136 return (DiagDirDiff)((uint)(d0 - d1) % 4);
137 }
138
149 inline DiagDirection ChangeDiagDir(DiagDirection d, DiagDirDiff delta)
150 {
151 assert(IsValidDiagDirection(d));
152 /* Cast to uint so compiler can use bitmask. Result can never be negative. */
153 return static_cast<DiagDirection>((static_cast<uint>(d) + static_cast<uint>(delta)) % 4);
154 }
155
166 inline DiagDirection DirToDiagDir(Direction dir)
167 {
168 assert(IsValidDirection(dir));
169 return (DiagDirection)(dir >> 1);
170 }
171
182 inline Direction DiagDirToDir(DiagDirection dir)
183 {
184 assert(IsValidDiagDirection(dir));
185 return (Direction)(dir * 2 + 1);
186 }
187
188
197 inline Axis OtherAxis(Axis a)
198 {
199 assert(IsValidAxis(a));
200 return (Axis)(a ^ 1);
201 }
202
203
214 inline Axis DiagDirToAxis(DiagDirection d)
215 {
216 assert(IsValidDiagDirection(d));
217 return (Axis)(d & 1);
218 }
219
220
232 inline DiagDirection AxisToDiagDir(Axis a)
233 {
234 assert(IsValidAxis(a));
235 return (DiagDirection)(2 - a);
236 }
237
249 inline Direction AxisToDirection(Axis a)
250 {
251 assert(IsValidAxis(a));
252 return (Direction)(5 - 2 * a);
253 }
254
261 inline DiagDirection XYNSToDiagDir(Axis xy, uint ns)
262 {
263 assert(IsValidAxis(xy));
264 return (DiagDirection)(xy * 3 ^ ns * 2);
265 }
266
273 inline bool IsDiagonalDirection(Direction dir)
274 {
275 assert(IsValidDirection(dir));
276 return (dir & 1) != 0;
277 }
278
279 #endif /* DIRECTION_FUNC_H */
ReverseDir
Direction ReverseDir(Direction d)
Return the reverse of a direction.
Definition: direction_func.h:54
direction_type.h
Direction
Direction
Defines the 8 directions on the map.
Definition: direction_type.h:24
AXIS_END
@ AXIS_END
Used for iterations.
Definition: direction_type.h:119
Axis
Axis
Allow incrementing of DiagDirDiff variables.
Definition: direction_type.h:116
DiagDirDiff
DiagDirDiff
Enumeration for the difference between to DiagDirection.
Definition: direction_type.h:95
DIAGDIR_END
@ DIAGDIR_END
Used for iterations.
Definition: direction_type.h:79
DiagDirToAxis
Axis DiagDirToAxis(DiagDirection d)
Convert a DiagDirection to the axis.
Definition: direction_func.h:214
AxisToDirection
Direction AxisToDirection(Axis a)
Converts an Axis to a Direction.
Definition: direction_func.h:249
ChangeDir
Direction ChangeDir(Direction d, DirDiff delta)
Change a direction by a given difference.
Definition: direction_func.h:104
DirDifference
DirDiff DirDifference(Direction d0, Direction d1)
Calculate the difference between two directions.
Definition: direction_func.h:68
ChangeDiagDir
DiagDirection ChangeDiagDir(DiagDirection d, DiagDirDiff delta)
Applies a difference on a DiagDirection.
Definition: direction_func.h:149
IsValidDirection
bool IsValidDirection(Direction d)
Checks if an integer value is a valid Direction.
Definition: direction_func.h:32
DiagDirDifference
DiagDirDiff DiagDirDifference(DiagDirection d0, DiagDirection d1)
Calculate the difference between two DiagDirection values.
Definition: direction_func.h:131
ReverseDiagDir
DiagDirection ReverseDiagDir(DiagDirection d)
Returns the reverse direction of the given DiagDirection.
Definition: direction_func.h:118
DiagDirToDir
Direction DiagDirToDir(DiagDirection dir)
Convert a DiagDirection to a Direction.
Definition: direction_func.h:182
AxisToDiagDir
DiagDirection AxisToDiagDir(Axis a)
Converts an Axis to a DiagDirection.
Definition: direction_func.h:232
DirToDiagDir
DiagDirection DirToDiagDir(Direction dir)
Convert a Direction to a DiagDirection.
Definition: direction_func.h:166
DirDiff
DirDiff
Allow incrementing of Direction variables.
Definition: direction_type.h:58
DiagDirection
DiagDirection
Enumeration for diagonal directions.
Definition: direction_type.h:73
IsValidAxis
bool IsValidAxis(Axis d)
Checks if an integer value is a valid Axis.
Definition: direction_func.h:43
IsDiagonalDirection
bool IsDiagonalDirection(Direction dir)
Checks if a given Direction is diagonal.
Definition: direction_func.h:273
IsValidDiagDirection
bool IsValidDiagDirection(DiagDirection d)
Checks if an integer value is a valid DiagDirection.
Definition: direction_func.h:21
DIR_END
@ DIR_END
Used to iterate.
Definition: direction_type.h:34
ChangeDirDiff
DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
Applies two differences together.
Definition: direction_func.h:88
OtherAxis
Axis OtherAxis(Axis a)
Select the other axis as provided.
Definition: direction_func.h:197
XYNSToDiagDir
DiagDirection XYNSToDiagDir(Axis xy, uint ns)
Convert an axis and a flag for north/south into a DiagDirection.
Definition: direction_func.h:261