OpenTTD Source: src/tilearea.cpp Source File

OpenTTD Source 1.11.0-RC1

tilearea.cpp
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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 #include "stdafx.h"
11
12 #include "tilearea_type.h"
13
14 #include "safeguards.h"
15
21 OrthogonalTileArea::OrthogonalTileArea(TileIndex start, TileIndex end)
22 {
23 assert(start < MapSize());
24 assert(end < MapSize());
25
26 uint sx = TileX(start);
27 uint sy = TileY(start);
28 uint ex = TileX(end);
29 uint ey = TileY(end);
30
31 if (sx > ex) Swap(sx, ex);
32 if (sy > ey) Swap(sy, ey);
33
34 this->tile = TileXY(sx, sy);
35 this->w = ex - sx + 1;
36 this->h = ey - sy + 1;
37 }
38
43 void OrthogonalTileArea::Add(TileIndex to_add)
44 {
45 if (this->tile == INVALID_TILE) {
46 this->tile = to_add;
47 this->w = 1;
48 this->h = 1;
49 return;
50 }
51
52 uint sx = TileX(this->tile);
53 uint sy = TileY(this->tile);
54 uint ex = sx + this->w - 1;
55 uint ey = sy + this->h - 1;
56
57 uint ax = TileX(to_add);
58 uint ay = TileY(to_add);
59
60 sx = std::min(ax, sx);
61 sy = std::min(ay, sy);
62 ex = std::max(ax, ex);
63 ey = std::max(ay, ey);
64
65 this->tile = TileXY(sx, sy);
66 this->w = ex - sx + 1;
67 this->h = ey - sy + 1;
68 }
69
75 bool OrthogonalTileArea::Intersects(const OrthogonalTileArea &ta) const
76 {
77 if (ta.w == 0 || this->w == 0) return false;
78
79 assert(ta.w != 0 && ta.h != 0 && this->w != 0 && this->h != 0);
80
81 uint left1 = TileX(this->tile);
82 uint top1 = TileY(this->tile);
83 uint right1 = left1 + this->w - 1;
84 uint bottom1 = top1 + this->h - 1;
85
86 uint left2 = TileX(ta.tile);
87 uint top2 = TileY(ta.tile);
88 uint right2 = left2 + ta.w - 1;
89 uint bottom2 = top2 + ta.h - 1;
90
91 return !(
92 left2 > right1 ||
93 right2 < left1 ||
94 top2 > bottom1 ||
95 bottom2 < top1
96 );
97 }
98
104 bool OrthogonalTileArea::Contains(TileIndex tile) const
105 {
106 if (this->w == 0) return false;
107
108 assert(this->w != 0 && this->h != 0);
109
110 uint left = TileX(this->tile);
111 uint top = TileY(this->tile);
112 uint tile_x = TileX(tile);
113 uint tile_y = TileY(tile);
114
115 return IsInsideBS(tile_x, left, this->w) && IsInsideBS(tile_y, top, this->h);
116 }
117
123 OrthogonalTileArea &OrthogonalTileArea::Expand(int rad)
124 {
125 int x = TileX(this->tile);
126 int y = TileY(this->tile);
127
128 int sx = std::max<int>(x - rad, 0);
129 int sy = std::max<int>(y - rad, 0);
130 int ex = std::min<int>(x + this->w + rad, MapSizeX());
131 int ey = std::min<int>(y + this->h + rad, MapSizeY());
132
133 this->tile = TileXY(sx, sy);
134 this->w = ex - sx;
135 this->h = ey - sy;
136 return *this;
137 }
138
142 void OrthogonalTileArea::ClampToMap()
143 {
144 assert(this->tile < MapSize());
145 this->w = std::min<int>(this->w, MapSizeX() - TileX(this->tile));
146 this->h = std::min<int>(this->h, MapSizeY() - TileY(this->tile));
147 }
148
154 DiagonalTileArea::DiagonalTileArea(TileIndex start, TileIndex end) : tile(start)
155 {
156 assert(start < MapSize());
157 assert(end < MapSize());
158
159 /* Unfortunately we can't find a new base and make all a and b positive because
160 * the new base might be a "flattened" corner where there actually is no single
161 * tile. If we try anyway the result is either inaccurate ("one off" half of the
162 * time) or the code gets much more complex;
163 *
164 * We also need to increment/decrement a and b here to have one-past-end semantics
165 * for a and b, just the way the orthogonal tile area does it for w and h. */
166
167 this->a = TileY(end) + TileX(end) - TileY(start) - TileX(start);
168 this->b = TileY(end) - TileX(end) - TileY(start) + TileX(start);
169 if (this->a > 0) {
170 this->a++;
171 } else {
172 this->a--;
173 }
174
175 if (this->b > 0) {
176 this->b++;
177 } else {
178 this->b--;
179 }
180 }
181
187 bool DiagonalTileArea::Contains(TileIndex tile) const
188 {
189 int a = TileY(tile) + TileX(tile);
190 int b = TileY(tile) - TileX(tile);
191
192 int start_a = TileY(this->tile) + TileX(this->tile);
193 int start_b = TileY(this->tile) - TileX(this->tile);
194
195 int end_a = start_a + this->a;
196 int end_b = start_b + this->b;
197
198 /* Swap if necessary, preserving the "one past end" semantics. */
199 if (start_a > end_a) {
200 int tmp = start_a;
201 start_a = end_a + 1;
202 end_a = tmp + 1;
203 }
204 if (start_b > end_b) {
205 int tmp = start_b;
206 start_b = end_b + 1;
207 end_b = tmp + 1;
208 }
209
210 return (a >= start_a && a < end_a && b >= start_b && b < end_b);
211 }
212
216 TileIterator &DiagonalTileIterator::operator++()
217 {
218 assert(this->tile != INVALID_TILE);
219
220 /* Determine the next tile, while clipping at map borders */
221 bool new_line = false;
222 do {
223 /* Iterate using the rotated coordinates. */
224 if (this->a_max == 1 || this->a_max == -1) {
225 /* Special case: Every second column has zero length, skip them completely */
226 this->a_cur = 0;
227 if (this->b_max > 0) {
228 this->b_cur = std::min(this->b_cur + 2, this->b_max);
229 } else {
230 this->b_cur = std::max(this->b_cur - 2, this->b_max);
231 }
232 } else {
233 /* Every column has at least one tile to process */
234 if (this->a_max > 0) {
235 this->a_cur += 2;
236 new_line = this->a_cur >= this->a_max;
237 } else {
238 this->a_cur -= 2;
239 new_line = this->a_cur <= this->a_max;
240 }
241 if (new_line) {
242 /* offset of initial a_cur: one tile in the same direction as a_max
243 * every second line.
244 */
245 this->a_cur = abs(this->a_cur) % 2 ? 0 : (this->a_max > 0 ? 1 : -1);
246
247 if (this->b_max > 0) {
248 ++this->b_cur;
249 } else {
250 --this->b_cur;
251 }
252 }
253 }
254
255 /* And convert the coordinates back once we've gone to the next tile. */
256 uint x = this->base_x + (this->a_cur - this->b_cur) / 2;
257 uint y = this->base_y + (this->b_cur + this->a_cur) / 2;
258 /* Prevent wrapping around the map's borders. */
259 this->tile = x >= MapSizeX() || y >= MapSizeY() ? INVALID_TILE : TileXY(x, y);
260 } while (this->tile > MapSize() && this->b_max != this->b_cur);
261
262 if (this->b_max == this->b_cur) this->tile = INVALID_TILE;
263 return *this;
264 }
TileIndex
uint32 TileIndex
The index/ID of a Tile.
Definition: tile_type.h:78
TileIterator::tile
TileIndex tile
The current tile we are at.
Definition: tilearea_type.h:101
DiagonalTileArea::DiagonalTileArea
DiagonalTileArea(TileIndex tile=INVALID_TILE, int8 a=0, int8 b=0)
Construct this tile area with some set values.
Definition: tilearea_type.h:76
DiagonalTileIterator::b_cur
int b_cur
The current (rotated) y coordinate of the iteration.
Definition: tilearea_type.h:193
TileY
static uint TileY(TileIndex tile)
Get the Y component of a tile.
Definition: map_func.h:215
OrthogonalTileArea::Add
void Add(TileIndex to_add)
Add a single tile to a tile area; enlarge if needed.
Definition: tilearea.cpp:43
DiagonalTileIterator::base_x
uint base_x
The base tile x coordinate from where the iterating happens.
Definition: tilearea_type.h:190
DiagonalTileArea::Contains
bool Contains(TileIndex tile) const
Does this tile area contain a tile?
Definition: tilearea.cpp:187
TileX
static uint TileX(TileIndex tile)
Get the X component of a tile.
Definition: map_func.h:205
OrthogonalTileArea::Intersects
bool Intersects(const OrthogonalTileArea &ta) const
Does this tile area intersect with another?
Definition: tilearea.cpp:75
MapSizeX
static uint MapSizeX()
Get the size of the map along the X.
Definition: map_func.h:72
MapSize
static uint MapSize()
Get the size of the map.
Definition: map_func.h:92
TileIterator
Base class for tile iterators.
Definition: tilearea_type.h:99
IsInsideBS
static bool IsInsideBS(const T x, const size_t base, const size_t size)
Checks if a value is between a window started at some base point.
Definition: math_func.hpp:188
OrthogonalTileArea::w
uint16 w
The width of the area.
Definition: tilearea_type.h:18
OrthogonalTileArea
Represents the covered area of e.g.
Definition: tilearea_type.h:16
DiagonalTileIterator::base_y
uint base_y
The base tile y coordinate from where the iterating happens.
Definition: tilearea_type.h:191
safeguards.h
MapSizeY
static uint MapSizeY()
Get the size of the map along the Y.
Definition: map_func.h:82
DiagonalTileArea::b
int16 b
Extent in diagonal "y" direction (may be negative to signify the area stretches upwards)
Definition: tilearea_type.h:68
stdafx.h
DiagonalTileIterator::a_max
int a_max
The (rotated) x coordinate of the end of the iteration.
Definition: tilearea_type.h:194
OrthogonalTileArea::h
uint16 h
The height of the area.
Definition: tilearea_type.h:19
tilearea_type.h
TileXY
static TileIndex TileXY(uint x, uint y)
Returns the TileIndex of a coordinate.
Definition: map_func.h:163
DiagonalTileArea::a
int16 a
Extent in diagonal "x" direction (may be negative to signify the area stretches to the left)
Definition: tilearea_type.h:67
OrthogonalTileArea::tile
TileIndex tile
The base tile of the area.
Definition: tilearea_type.h:17
abs
static T abs(const T a)
Returns the absolute value of (scalar) variable.
Definition: math_func.hpp:21
DiagonalTileIterator::operator++
TileIterator & operator++()
Move ourselves to the next tile in the rectangle on the map.
Definition: tilearea.cpp:216
DiagonalTileArea::tile
TileIndex tile
Base tile of the area.
Definition: tilearea_type.h:66
INVALID_TILE
static const TileIndex INVALID_TILE
The very nice invalid tile marker.
Definition: tile_type.h:83
OrthogonalTileArea::Expand
OrthogonalTileArea & Expand(int rad)
Expand a tile area by rad tiles in each direction, keeping within map bounds.
Definition: tilearea.cpp:123
OrthogonalTileArea::OrthogonalTileArea
OrthogonalTileArea(TileIndex tile=INVALID_TILE, uint8 w=0, uint8 h=0)
Construct this tile area with some set values.
Definition: tilearea_type.h:27
Swap
static void Swap(T &a, T &b)
Type safe swap operation.
Definition: math_func.hpp:215
OrthogonalTileArea::ClampToMap
void ClampToMap()
Clamp the tile area to map borders.
Definition: tilearea.cpp:142
DiagonalTileIterator::b_max
int b_max
The (rotated) y coordinate of the end of the iteration.
Definition: tilearea_type.h:195
OrthogonalTileArea::Contains
bool Contains(TileIndex tile) const
Does this tile area contain a tile?
Definition: tilearea.cpp:104
DiagonalTileIterator::a_cur
int a_cur
The current (rotated) x coordinate of the iteration.
Definition: tilearea_type.h:192