tron@2186: /* $Id$ */
tron@2186: 
darkvater@1213: #include "stdafx.h"
tron@1211: #include "tile.h"
tron@1211: 
tron@1211: void SetMapExtraBits(TileIndex tile, byte bits)
tron@1211: {
tron@1211: 	assert(tile < MapSize());
tron@2049: 	SB(_m[tile].extra, 0, 2, bits & 3);
tron@1211: }
tron@1211: 
tron@1211: uint GetMapExtraBits(TileIndex tile)
tron@1211: {
tron@1211: 	assert(tile < MapSize());
tron@2049: 	return GB(_m[tile].extra, 0, 2);
tron@1211: }
tron@1335: 
celestar@3279: /** Converts the heights of 4 corners into a tileh, and returns the minimum height of the tile
celestar@3279:   * @param n,w,e,s the four corners
celestar@3279:   * @param h uint pointer to write the height to
celestar@3279:   * @return the tileh
celestar@3279: */
celestar@3279: uint GetTileh(uint n, uint w, uint e, uint s, uint *h)
celestar@3279: {
celestar@3279: 	uint min = n;
celestar@3279: 	uint r;
celestar@3279: 
celestar@3279: 	if (min >= w) min = w;
celestar@3279: 	if (min >= e) min = e;
celestar@3279: 	if (min >= s) min = s;
celestar@3279: 
celestar@3279: 	r = 0;
celestar@3279: 	if ((n -= min) != 0) r += (--n << 4) + 8;
celestar@3279: 	if ((e -= min) != 0) r += (--e << 4) + 4;
celestar@3279: 	if ((s -= min) != 0) r += (--s << 4) + 2;
celestar@3279: 	if ((w -= min) != 0) r += (--w << 4) + 1;
celestar@3279: 
celestar@3279: 	if (h != NULL) *h = min * 8;
celestar@3279: 
celestar@3279: 	return r;
celestar@3279: }
tron@1335: 
tron@1335: uint GetTileSlope(TileIndex tile, uint *h)
tron@1335: {
tron@1335: 	uint a;
tron@1335: 	uint b;
tron@1335: 	uint c;
tron@1335: 	uint d;
tron@1335: 
tron@1335: 	assert(tile < MapSize());
tron@1335: 
tron@1335: 	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) {
tron@1335: 		if (h != NULL) *h = 0;
tron@1335: 		return 0;
tron@1335: 	}
tron@1335: 
celestar@3279: 	a = TileHeight(tile);
tron@1981: 	b = TileHeight(tile + TileDiffXY(1, 0));
tron@1981: 	c = TileHeight(tile + TileDiffXY(0, 1));
tron@1981: 	d = TileHeight(tile + TileDiffXY(1, 1));
tron@1335: 
celestar@3279: 	return GetTileh(a, b, c, d, h);
tron@1335: }
tron@1335: 
tron@1335: uint GetTileZ(TileIndex tile)
tron@1335: {
tron@1335: 	uint h;
tron@1335: 	GetTileSlope(tile, &h);
tron@1335: 	return h;
tron@1335: }