/** Convert to or from snowy tiles. */
static void TileLoopClearAlps(TileIndex tile)
{
int k = GetTileZ(tile) - GetSnowLine() + 1;
if (k < 0) {
/* Below the snow line, do nothing if no snow. */
if (!IsSnowTile(tile)) return;
} else {
/* At or above the snow line, make snow tile if needed. */
if (!IsSnowTile(tile)) {
MakeSnow(tile);
MarkTileDirtyByTile(tile);
return;
}
}
/* Update snow density. */
uint current_density = GetClearDensity(tile);
uint req_density = (k < 0) ? 0u : min((uint)k, 3);
if (current_density < req_density) {
AddClearDensity(tile, 1);
} else if (current_density > req_density) {
AddClearDensity(tile, -1);
} else {
/* Density at the required level. */
if (k >= 0) return;
ClearSnow(tile);
}
MarkTileDirtyByTile(tile);
}
static void TileLoop_Trees(TileIndex tile)
{
if (GetTreeGround(tile) == TREE_GROUND_SHORE) {
TileLoop_Water(tile);
} else {
switch (_settings_game.game_creation.landscape) {
case LT_TROPIC: TileLoopTreesDesert(tile); break;
case LT_ARCTIC: TileLoopTreesAlps(tile); break;
}
}
TileLoopClearHelper(tile);
uint treeCounter = GetTreeCounter(tile);
/* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
uint density = GetTreeDensity(tile);
if (density < 3) {
SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
MarkTileDirtyByTile(tile);
}
}
if (GetTreeCounter(tile) < 15) {
AddTreeCounter(tile, 1);
return;
}
SetTreeCounter(tile, 0);
switch (GetTreeGrowth(tile)) {
case 3: // regular sized tree
if (_settings_game.game_creation.landscape == LT_TROPIC &&
GetTreeType(tile) != TREE_CACTUS &&
GetTropicZone(tile) == TROPICZONE_DESERT) {
AddTreeGrowth(tile, 1);
} else {
switch (GB(Random(), 0, 3)) {
case 0: // start destructing
AddTreeGrowth(tile, 1);
break;
case 1: // add a tree
if (GetTreeCount(tile) < 4) {
AddTreeCount(tile, 1);
SetTreeGrowth(tile, 0);
break;
}
/* FALL THROUGH */
case 2: { // add a neighbouring tree
/* Don't plant extra trees if that's not allowed. */
if ((_settings_game.game_creation.landscape == LT_TROPIC && GetTropicZone(tile) == TROPICZONE_RAINFOREST) ?
_settings_game.construction.extra_tree_placement == ETP_NONE :
_settings_game.construction.extra_tree_placement != ETP_ALL) {
break;
}
TreeType treetype = GetTreeType(tile);
tile += TileOffsByDir((Direction)(Random() & 7));
/* Cacti don't spread */
if (!CanPlantTreesOnTile(tile, false)) return;
/* Don't plant trees, if ground was freshly cleared */
if (IsTileType(tile, MP_CLEAR) && GetClearGround(tile) == CLEAR_GRASS && GetClearDensity(tile) != 3) return;
PlantTreesOnTile(tile, treetype, 0, 0);
break;
}
default:
return;
}
}
break;
case 6: // final stage of tree destruction
if (GetTreeCount(tile) > 1) {
/* more than one tree, delete it */
AddTreeCount(tile, -1);
SetTreeGrowth(tile, 3);
} else {
/* just one tree, change type into MP_CLEAR */
switch (GetTreeGround(tile)) {
case TREE_GROUND_SHORE: MakeShore(tile); break;
case TREE_GROUND_GRASS: MakeClear(tile, CLEAR_GRASS, GetTreeDensity(tile)); break;
case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
case TREE_GROUND_ROUGH_SNOW: {
uint density = GetTreeDensity(tile);
MakeClear(tile, CLEAR_ROUGH, 3);
MakeSnow(tile, density);
break;
}
default: // snow or desert
if (_settings_game.game_creation.landscape == LT_TROPIC) {
MakeClear(tile, CLEAR_DESERT, GetTreeDensity(tile));
} else {
uint density = GetTreeDensity(tile);
MakeClear(tile, CLEAR_GRASS, 3);
MakeSnow(tile, density);
}
break;
}
}
break;
default:
AddTreeGrowth(tile, 1);
break;
}
MarkTileDirtyByTile(tile);
}
