/** A small helper function to initialize the terrain */
static void TgenSetTileHeight(TileIndex tile, int height)
{
SetTileHeight(tile, height);
/* Only clear the tiles within the map area. */
if (IsInnerTile(tile)) {
MakeClear(tile, CLEAR_GRASS, 3);
}
}
/**
* Return the slope of a given tile inside the map.
* @param tile Tile to compute slope of
* @param h If not \c NULL, pointer to storage of z height
* @return Slope of the tile, except for the HALFTILE part
*/
Slope GetTileSlope(TileIndex tile, int *h)
{
assert(tile < MapSize());
if (!IsInnerTile(tile)) {
if (h != NULL) *h = TileHeight(tile);
return SLOPE_FLAT;
}
int hnorth = TileHeight(tile); // Height of the North corner.
int hwest = TileHeight(tile + TileDiffXY(1, 0)); // Height of the West corner.
int heast = TileHeight(tile + TileDiffXY(0, 1)); // Height of the East corner.
int hsouth = TileHeight(tile + TileDiffXY(1, 1)); // Height of the South corner.
return GetTileSlopeGivenHeight(hnorth, hwest, heast, hsouth, h);
}
/**
* Check if a given tile is flat
* @param tile Tile to check
* @param h If not \c NULL, pointer to storage of z height (only if tile is flat)
* @return Whether the tile is flat
*/
bool IsTileFlat(TileIndex tile, int *h)
{
assert(tile < MapSize());
if (!IsInnerTile(tile)) {
if (h != NULL) *h = TileHeight(tile);
return true;
}
uint z = TileHeight(tile);
if (TileHeight(tile + TileDiffXY(1, 0)) != z) return false;
if (TileHeight(tile + TileDiffXY(0, 1)) != z) return false;
if (TileHeight(tile + TileDiffXY(1, 1)) != z) return false;
if (h != NULL) *h = z;
return true;
}
/**
* Converts a given grayscale map to something that fits in OTTD map system
* and create a map of that data.
* @param img_width the with of the image in pixels/tiles
* @param img_height the height of the image in pixels/tiles
* @param map the input map
*/
static void GrayscaleToMapHeights(uint img_width, uint img_height, byte *map)
{
/* Defines the detail of the aspect ratio (to avoid doubles) */
const uint num_div = 16384;
uint width, height;
uint row, col;
uint row_pad = 0, col_pad = 0;
uint img_scale;
uint img_row, img_col;
TileIndex tile;
/* Get map size and calculate scale and padding values */
switch (_settings_game.game_creation.heightmap_rotation) {
default: NOT_REACHED();
case HM_COUNTER_CLOCKWISE:
width = MapSizeX();
height = MapSizeY();
break;
case HM_CLOCKWISE:
width = MapSizeY();
height = MapSizeX();
break;
}
if ((img_width * num_div) / img_height > ((width * num_div) / height)) {
/* Image is wider than map - center vertically */
img_scale = (width * num_div) / img_width;
row_pad = (1 + height - ((img_height * img_scale) / num_div)) / 2;
} else {
/* Image is taller than map - center horizontally */
img_scale = (height * num_div) / img_height;
col_pad = (1 + width - ((img_width * img_scale) / num_div)) / 2;
}
if (_settings_game.construction.freeform_edges) {
for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
}
/* Form the landscape */
for (row = 0; row < height; row++) {
for (col = 0; col < width; col++) {
switch (_settings_game.game_creation.heightmap_rotation) {
default: NOT_REACHED();
case HM_COUNTER_CLOCKWISE: tile = TileXY(col, row); break;
case HM_CLOCKWISE: tile = TileXY(row, col); break;
}
/* Check if current tile is within the 1-pixel map edge or padding regions */
if ((!_settings_game.construction.freeform_edges && DistanceFromEdge(tile) <= 1) ||
(row < row_pad) || (row >= (height - row_pad - (_settings_game.construction.freeform_edges ? 0 : 1))) ||
(col < col_pad) || (col >= (width - col_pad - (_settings_game.construction.freeform_edges ? 0 : 1)))) {
SetTileHeight(tile, 0);
} else {
/* Use nearest neighbour resizing to scale map data.
* We rotate the map 45 degrees (counter)clockwise */
img_row = (((row - row_pad) * num_div) / img_scale);
switch (_settings_game.game_creation.heightmap_rotation) {
default: NOT_REACHED();
case HM_COUNTER_CLOCKWISE:
img_col = (((width - 1 - col - col_pad) * num_div) / img_scale);
break;
case HM_CLOCKWISE:
img_col = (((col - col_pad) * num_div) / img_scale);
break;
}
assert(img_row < img_height);
assert(img_col < img_width);
uint heightmap_height = map[img_row * img_width + img_col];
if (heightmap_height > 0) {
/* 0 is sea level.
* Other grey scales are scaled evenly to the available height levels > 0.
* (The coastline is independent from the number of height levels) */
heightmap_height = 1 + (heightmap_height - 1) * _settings_game.construction.max_heightlevel / 255;
}
SetTileHeight(tile, heightmap_height);
}
/* Only clear the tiles within the map area. */
if (IsInnerTile(tile)) {
MakeClear(tile, CLEAR_GRASS, 3);
}
}
}
}