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(svn r19670) -Codechange: Add CeilDiv() and RoundDiv() to simplify integer divisions with rounding.

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frosch
2010-04-18 14:56:05 +00:00
parent 2330851d1d
commit 2e90f7f8b9
15 changed files with 50 additions and 30 deletions
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11
src/map_func.h
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@@ -12,6 +12,7 @@
#ifndef MAP_FUNC_H
#define MAP_FUNC_H
#include "core/math_func.hpp"
#include "tile_type.h"
#include "map_type.h"
#include "direction_func.h"
@@ -126,9 +127,8 @@ static inline uint MapMaxY()
static inline uint ScaleByMapSize(uint n)
{
/* Subtract 12 from shift in order to prevent integer overflow
* for large values of n. It's safe since the min mapsize is 64x64.
* Add (1<<4)-1 to round upwards. */
return ((n << (MapLogX() + MapLogY() - 12)) + (1 << 4) - 1) >> 4;
* for large values of n. It's safe since the min mapsize is 64x64. */
return CeilDiv(n << (MapLogX() + MapLogY() - 12), 1 << 4);
}
@@ -142,9 +142,8 @@ static inline uint ScaleByMapSize1D(uint n)
{
/* Normal circumference for the X+Y is 256+256 = 1<<9
* Note, not actually taking the full circumference into account,
* just half of it.
* (1<<9) - 1 is there to scale upwards. */
return ((n << MapLogX()) + (n << MapLogY()) + (1 << 9) - 1) >> 9;
* just half of it. */
return CeilDiv((n << MapLogX()) + (n << MapLogY()), 1 << 9);
}
/**