rubidium@9723: /* $Id$ */
rubidium@9723: 
rubidium@10455: /** @file tile_map.cpp Global tile accessors. */
rubidium@9723: 
rubidium@9723: #include "stdafx.h"
rubidium@9723: #include "openttd.h"
rubidium@9723: #include "tile_map.h"
rubidium@9723: #include "core/math_func.hpp"
rubidium@9723: 
rubidium@9723: Slope GetTileSlope(TileIndex tile, uint *h)
rubidium@9723: {
rubidium@9723: 	uint a;
rubidium@9723: 	uint b;
rubidium@9723: 	uint c;
rubidium@9723: 	uint d;
rubidium@9723: 	uint min;
rubidium@9723: 	uint r;
rubidium@9723: 
rubidium@9723: 	assert(tile < MapSize());
rubidium@9723: 
rubidium@9723: 	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) {
rubidium@9723: 		if (h != NULL) *h = 0;
rubidium@9723: 		return SLOPE_FLAT;
rubidium@9723: 	}
rubidium@9723: 
rubidium@9723: 	min = a = TileHeight(tile);
rubidium@9723: 	b = TileHeight(tile + TileDiffXY(1, 0));
rubidium@9723: 	if (min > b) min = b;
rubidium@9723: 	c = TileHeight(tile + TileDiffXY(0, 1));
rubidium@9723: 	if (min > c) min = c;
rubidium@9723: 	d = TileHeight(tile + TileDiffXY(1, 1));
rubidium@9723: 	if (min > d) min = d;
rubidium@9723: 
rubidium@9723: 	r = SLOPE_FLAT;
rubidium@9723: 	if ((a -= min) != 0) r += (--a << 4) + SLOPE_N;
rubidium@9723: 	if ((c -= min) != 0) r += (--c << 4) + SLOPE_E;
rubidium@9723: 	if ((d -= min) != 0) r += (--d << 4) + SLOPE_S;
rubidium@9723: 	if ((b -= min) != 0) r += (--b << 4) + SLOPE_W;
rubidium@9723: 
rubidium@9723: 	if (h != NULL) *h = min * TILE_HEIGHT;
rubidium@9723: 
rubidium@9723: 	return (Slope)r;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: uint GetTileZ(TileIndex tile)
rubidium@9723: {
rubidium@9723: 	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) return 0;
rubidium@9723: 
rubidium@9723: 	uint h = TileHeight(tile);
rubidium@9723: 	h = min(h, TileHeight(tile + TileDiffXY(1, 0)));
rubidium@9723: 	h = min(h, TileHeight(tile + TileDiffXY(0, 1)));
rubidium@9723: 	h = min(h, TileHeight(tile + TileDiffXY(1, 1)));
rubidium@9723: 
rubidium@9723: 	return h * TILE_HEIGHT;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: 
rubidium@9723: uint GetTileMaxZ(TileIndex t)
rubidium@9723: {
rubidium@9723: 	if (TileX(t) == MapMaxX() || TileY(t) == MapMaxY()) return 0;
rubidium@9723: 
rubidium@9723: 	uint h = TileHeight(t);
rubidium@9723: 	h = max(h, TileHeight(t + TileDiffXY(1, 0)));
rubidium@9723: 	h = max(h, TileHeight(t + TileDiffXY(0, 1)));
rubidium@9723: 	h = max(h, TileHeight(t + TileDiffXY(1, 1)));
rubidium@9723: 
rubidium@9723: 	return h * TILE_HEIGHT;
rubidium@9723: }