1 /* $Id$ */

     2 

     3 /** @file tile.cpp */

     4 

     5 #include "stdafx.h"

     6 #include "tile.h"

     7 

     8 Slope GetTileSlope(TileIndex tile, uint *h)

     9 {

    10 	uint a;

    11 	uint b;

    12 	uint c;

    13 	uint d;

    14 	uint min;

    15 	uint r;

    16 

    17 	assert(tile < MapSize());

    18 

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

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

    21 		return SLOPE_FLAT;

    22 	}

    23 

    24 	min = a = TileHeight(tile);

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

    26 	if (min > b) min = b;

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

    28 	if (min > c) min = c;

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

    30 	if (min > d) min = d;

    31 

    32 	r = SLOPE_FLAT;

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

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

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

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

    37 

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

    39 

    40 	return (Slope)r;

    41 }

    42 

    43 uint GetTileZ(TileIndex tile)

    44 {

    45 	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) return 0;

    46 

    47 	uint h = TileHeight(tile);

    48 	h = min(h, TileHeight(tile + TileDiffXY(1, 0)));

    49 	h = min(h, TileHeight(tile + TileDiffXY(0, 1)));

    50 	h = min(h, TileHeight(tile + TileDiffXY(1, 1)));

    51 

    52 	return h * TILE_HEIGHT;

    53 }

    54 

    55 

    56 uint GetTileMaxZ(TileIndex t)

    57 {

    58 	if (TileX(t) == MapMaxX() || TileY(t) == MapMaxY()) return 0;

    59 

    60 	uint h = TileHeight(t);

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

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

    63 	h = max(h, TileHeight(t + TileDiffXY(1, 1)));

    64 

    65 	return h * TILE_HEIGHT;

    66 }