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(svn r26908) -Codechange: replace a magic number by a more logical calculation

release/1.5
rubidium 2014-09-22 15:04:18 +00:00
parent c64586ea44
commit adf237d550
1 changed files with 7 additions and 5 deletions
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12
src/viewport.cpp
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@ -419,11 +419,13 @@ static Point TranslateXYToTileCoord(const ViewPort *vp, int x, int y)
a = y - x;
b = y + x;
/* we need to move variables in to the valid range, as the
* GetTileZoomCenterWindow() function can call here with invalid x and/or y,
* when the user tries to zoom out along the sides of the map */
a = Clamp(a, -4 * (int)TILE_SIZE, (int)(MapMaxX() * TILE_SIZE) - 1);
b = Clamp(b, -4 * (int)TILE_SIZE, (int)(MapMaxY() * TILE_SIZE) - 1);
/* Bring the coordinates near to a valid range. This is mostly due to the
* tiles on the north side of the map possibly being drawn too high due to
* the extra height levels. So at the top we allow a number of extra tiles.
* This number is based on the tile height and pixels. */
int extra_tiles = CeilDiv(_settings_game.construction.max_heightlevel * TILE_HEIGHT, TILE_PIXELS);
a = Clamp(a, -extra_tiles * TILE_SIZE, MapMaxX() * TILE_SIZE - 1);
b = Clamp(b, -extra_tiles * TILE_SIZE, MapMaxY() * TILE_SIZE - 1);
/* (a, b) is the X/Y-world coordinate that belongs to (x,y) if the landscape would be completely flat on height 0.
* Now find the Z-world coordinate by fix point iteration.