1 /* $Id$ */

     2 

     3 #include "stdafx.h"

     4 #include "tile.h"

     5 

     6 Slope GetTileSlope(TileIndex tile, uint *h)

     7 {

     8 	uint a;

     9 	uint b;

    10 	uint c;

    11 	uint d;

    12 	uint min;

    13 	uint r;

    14 

    15 	assert(tile < MapSize());

    16 

    17 	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) {

    18 		if (h != NULL) *h = 0;

    19 		return 0;

    20 	}

    21 

    22 	min = a = TileHeight(tile);

    23 	b = TileHeight(tile + TileDiffXY(1, 0));

    24 	if (min >= b) min = b;

    25 	c = TileHeight(tile + TileDiffXY(0, 1));

    26 	if (min >= c) min = c;

    27 	d = TileHeight(tile + TileDiffXY(1, 1));

    28 	if (min >= d) min = d;

    29 

    30 	r = SLOPE_FLAT;

    31 	if ((a -= min) != 0) r += (--a << 4) + SLOPE_N;

    32 	if ((c -= min) != 0) r += (--c << 4) + SLOPE_E;

    33 	if ((d -= min) != 0) r += (--d << 4) + SLOPE_S;

    34 	if ((b -= min) != 0) r += (--b << 4) + SLOPE_W;

    35 

    36 	if (h != NULL) *h = min * TILE_HEIGHT;

    37 

    38 	return r;

    39 }

    40 

    41 uint GetTileZ(TileIndex tile)

    42 {

    43 	uint h;

    44 	GetTileSlope(tile, &h);

    45 	return h;

    46 }

    47 

    48 

    49 uint GetTileMaxZ(TileIndex t)

    50 {

    51 	uint max;

    52 	uint h;

    53 

    54 	h = TileHeight(t);

    55 	max = h;

    56 	h = TileHeight(t + TileDiffXY(1, 0));

    57 	if (h > max) max = h;

    58 	h = TileHeight(t + TileDiffXY(0, 1));

    59 	if (h > max) max = h;

    60 	h = TileHeight(t + TileDiffXY(1, 1));

    61 	if (h > max) max = h;

    62 	return max * 8;

    63 }