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authorrubidium <rubidium@openttd.org>2007-04-27 21:29:36 +0000
committerrubidium <rubidium@openttd.org>2007-04-27 21:29:36 +0000
commite1057864d8254e35854918b2b60db6dc43025ecf (patch)
tree8790ce91b35114408651cb1421df817c7c9e66cc /src/map.cpp
parent75ba8f4489bce6ff017fd45bd387c87b37f7e8d4 (diff)
downloadopenttd-e1057864d8254e35854918b2b60db6dc43025ecf.tar.xz
(svn r9729) -Documentation: add some documentation in various places
Diffstat (limited to 'src/map.cpp')
-rw-r--r--src/map.cpp87
1 files changed, 74 insertions, 13 deletions
diff --git a/src/map.cpp b/src/map.cpp
index 092603b4d..5e511772f 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -16,24 +16,29 @@
extern "C" _CRTIMP void __cdecl _assert(void *, void *, unsigned);
#endif
-uint _map_log_x;
-uint _map_size_x;
-uint _map_size_y;
-uint _map_tile_mask;
-uint _map_size;
+uint _map_log_x; ///< 2^_map_log_x == _map_size_x
+uint _map_size_x; ///< Size of the map along the X
+uint _map_size_y; ///< Size of the map along the Y
+uint _map_size; ///< The number of tiles on the map
+uint _map_tile_mask; ///< _map_size - 1 (to mask the mapsize)
-Tile *_m = NULL;
-TileExtended *_me = NULL;
+Tile *_m = NULL; ///< Tiles of the map
+TileExtended *_me = NULL; ///< Extended Tiles of the map
+/**
+ * (Re)allocates a map with the given dimension
+ * @param size_x the width of the map along the NE/SW edge
+ * @param size_y the 'height' of the map along the SE/NW edge
+ */
void AllocateMap(uint size_x, uint size_y)
{
/* Make sure that the map size is within the limits and that
* the x axis size is a power of 2. */
if (size_x < 64 || size_x > 2048 ||
size_y < 64 || size_y > 2048 ||
- (size_x&(size_x-1)) != 0 ||
- (size_y&(size_y-1)) != 0)
+ (size_x & (size_x - 1)) != 0 ||
+ (size_y & (size_y - 1)) != 0)
error("Invalid map size");
DEBUG(map, 1, "Allocating map of size %dx%d", size_x, size_y);
@@ -92,7 +97,12 @@ TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
}
#endif
-
+/**
+ * Scales the given value by the map size, where the given value is
+ * for a 256 by 256 map
+ * @param n the value to scale
+ * @return the scaled size
+ */
uint ScaleByMapSize(uint n)
{
/* First shift by 12 to prevent integer overflow for large values of n.
@@ -102,7 +112,12 @@ uint ScaleByMapSize(uint n)
}
-/* Scale relative to the circumference of the map */
+/**
+ * Scales the given value by the maps circumference, where the given
+ * value is for a 256 by 256 map
+ * @param n the value to scale
+ * @return the scaled size
+ */
uint ScaleByMapSize1D(uint n)
{
/* Normal circumference for the X+Y is 256+256 = 1<<9
@@ -113,12 +128,18 @@ uint ScaleByMapSize1D(uint n)
}
-/* This function checks if we add addx/addy to tile, if we
+/**
+ * This function checks if we add addx/addy to tile, if we
* do wrap around the edges. For example, tile = (10,2) and
* addx = +3 and addy = -4. This function will now return
* INVALID_TILE, because the y is wrapped. This is needed in
* for example, farmland. When the tile is not wrapped,
- * the result will be tile + TileDiffXY(addx, addy) */
+ * the result will be tile + TileDiffXY(addx, addy)
+ * @param tile the 'starting' point of the adding
+ * @param addx the amount of tiles in the X direction to add
+ * @param addy the amount of tiles in the Y direction to add
+ * @return translated tile, or INVALID_TILE when it would've wrapped.
+ */
uint TileAddWrap(TileIndex tile, int addx, int addy)
{
uint x = TileX(tile) + addx;
@@ -131,6 +152,7 @@ uint TileAddWrap(TileIndex tile, int addx, int addy)
return INVALID_TILE;
}
+/** 'Lookup table' for tile offsets given a DiagDirection */
extern const TileIndexDiffC _tileoffs_by_diagdir[] = {
{-1, 0}, ///< DIAGDIR_NE
{ 0, 1}, ///< DIAGDIR_SE
@@ -138,6 +160,7 @@ extern const TileIndexDiffC _tileoffs_by_diagdir[] = {
{ 0, -1} ///< DIAGDIR_NW
};
+/** 'Lookup table' for tile offsets given a Direction */
extern const TileIndexDiffC _tileoffs_by_dir[] = {
{-1, -1}, ///< DIR_N
{-1, 0}, ///< DIR_NE
@@ -149,6 +172,15 @@ extern const TileIndexDiffC _tileoffs_by_dir[] = {
{ 0, -1} ///< DIR_NW
};
+/**
+ * Gets the Manhattan distance between the two given tiles.
+ * The Manhattan distance is the sum of the delta of both the
+ * X and Y component.
+ * Also known as L1-Norm
+ * @param t0 the start tile
+ * @param t1 the end tile
+ * @return the distance
+ */
uint DistanceManhattan(TileIndex t0, TileIndex t1)
{
const uint dx = delta(TileX(t0), TileX(t1));
@@ -157,6 +189,15 @@ uint DistanceManhattan(TileIndex t0, TileIndex t1)
}
+/**
+ * Gets the 'Square' distance between the two given tiles.
+ * The 'Square' distance is the square of the shortest (straight line)
+ * distance between the two tiles.
+ * Also known as euclidian- or L2-Norm squared.
+ * @param t0 the start tile
+ * @param t1 the end tile
+ * @return the distance
+ */
uint DistanceSquare(TileIndex t0, TileIndex t1)
{
const int dx = TileX(t0) - TileX(t1);
@@ -165,6 +206,13 @@ uint DistanceSquare(TileIndex t0, TileIndex t1)
}
+/**
+ * Gets the biggest distance component (x or y) between the two given tiles.
+ * Also known as L-Infinity-Norm.
+ * @param t0 the start tile
+ * @param t1 the end tile
+ * @return the distance
+ */
uint DistanceMax(TileIndex t0, TileIndex t1)
{
const uint dx = delta(TileX(t0), TileX(t1));
@@ -173,6 +221,14 @@ uint DistanceMax(TileIndex t0, TileIndex t1)
}
+/**
+ * Gets the biggest distance component (x or y) between the two given tiles
+ * plus the Manhattan distance, i.e. two times the biggest distance component
+ * and once the smallest component.
+ * @param t0 the start tile
+ * @param t1 the end tile
+ * @return the distance
+ */
uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1)
{
const uint dx = delta(TileX(t0), TileX(t1));
@@ -180,6 +236,11 @@ uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1)
return dx > dy ? 2 * dx + dy : 2 * dy + dx;
}
+/**
+ * Param the minimum distance to an edge
+ * @param tile the tile to get the distance from
+ * @return the distance from the edge in tiles
+ */
uint DistanceFromEdge(TileIndex tile)
{
const uint xl = TileX(tile);