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: 
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: 	uint min;
tron@1335: 	uint r;
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: 
tron@1335: 	min = a = TileHeight(tile);
tron@1981: 	b = TileHeight(tile + TileDiffXY(1, 0));
tron@1335: 	if (min >= b) min = b;
tron@1981: 	c = TileHeight(tile + TileDiffXY(0, 1));
tron@1335: 	if (min >= c) min = c;
tron@1981: 	d = TileHeight(tile + TileDiffXY(1, 1));
tron@1335: 	if (min >= d) min = d;
tron@1335: 
tron@1335: 	r = 0;
tron@2549: 	if ((a -= min) != 0) r += (--a << 4) + 8;
tron@2549: 	if ((c -= min) != 0) r += (--c << 4) + 4;
tron@2549: 	if ((d -= min) != 0) r += (--d << 4) + 2;
tron@2549: 	if ((b -= min) != 0) r += (--b << 4) + 1;
tron@1335: 
tron@1335: 	if (h != NULL)
tron@1335: 		*h = min * 8;
tron@1335: 
tron@1335: 	return r;
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: }