public UpdateSnowLayerChunk UpdateSnowLayer(SnowAccumSnapshot sumsnapshot, bool ignoreOldAccum, IServerMapChunk mc, Vec2i chunkPos, IWorldChunk[] chunksCol)
{
UpdateSnowLayerChunk updateChunk = new UpdateSnowLayerChunk();
var layers = ws.GeneralConfig.SnowLayerBlocks;
int chunkX = chunkPos.X;
int chunkZ = chunkPos.Y;
int regionX = (chunkX * chunksize) / regionsize;
int regionZ = (chunkZ * chunksize) / regionsize;
int regionBasePosX = regionX * regionsize;
int regionBasePosZ = regionZ * regionsize;
BlockPos pos = new BlockPos();
BlockPos placePos = new BlockPos();
float aboveSeaLevelHeight = sapi.World.BlockAccessor.MapSizeY - sapi.World.SeaLevel;
int[] posIndices = randomShuffles[sapi.World.Rand.Next(randomShuffles.Length)];
int prevChunkY = -99999;
IWorldChunk chunk = null;
int maxY = sapi.World.BlockAccessor.MapSizeY - 1;
for (int i = 0; i < posIndices.Length; i++)
{
int posIndex = posIndices[i];
int posY = GameMath.Clamp(mc.RainHeightMap[posIndex], 0, maxY);
int chunkY = posY / chunksize;
pos.Set(
chunkX * chunksize + posIndex % chunksize,
posY,
chunkZ * chunksize + posIndex / chunksize
);
if (prevChunkY != chunkY)
{
chunk = chunksCol?[chunkY] ?? sapi.WorldManager.GetChunk(chunkX, chunkY, chunkZ);
prevChunkY = chunkY;
}
if (chunk == null)
{
return(null);
}
float relx = (pos.X - regionBasePosX) / (float)regionsize;
float rely = GameMath.Clamp((pos.Y - sapi.World.SeaLevel) / aboveSeaLevelHeight, 0, 1);
float relz = (pos.Z - regionBasePosZ) / (float)regionsize;
// What needs to be done here?
// 1. Get desired snow cover level
// 2. Get current snow cover level
// - Get topmmost block. Is it snow?
// - Yes. Use it as reference pos and stuff
// - No. Must have no snow, increment pos.Y by 1
// 3. Compare and place block accordingly
// Idea: New method Block.UpdateSnowLayer() returns a new block instance if a block change is needed
// What needs to be done here, take 2
// We have 3 possible cases per-block
// 1: We find upside solid block. That means it has no snow on top
// 2: We find snow. That means below is a solid block.
// 3: We find some other block: That means we should try to find its snow-covered variant
// We have the following input data
// 1. Snow accumulation changes since the last update (usually an in-game hour or 2)
// 2. A precise snow level value from the position (if not set, load from snowlayer block type) (set to zero if the snowlayer is removed)
// 3. The current block at position, which is either
// - A snow layer: Override with internal level + accum changes
// - A solid block: Plase snow on top based on internal level + accum changes
// - A snow variantable block: Call the method with the new level
Block block = chunk.GetLocalLiquidOrBlockAtBlockPos(sapi.World, pos);
float hereAccum = 0;
Vec2i vec = new Vec2i(pos.X, pos.Z);
if (!ignoreOldAccum && !mc.SnowAccum.TryGetValue(vec, out hereAccum))
{
hereAccum = block.GetSnowLevel(pos);
}
float nowAccum = hereAccum + sumsnapshot.GetAvgSnowAccumByRegionCorner(relx, rely, relz);
mc.SnowAccum[vec] = GameMath.Clamp(nowAccum, -1, ws.GeneralConfig.SnowLayerBlocks.Count + 0.6f);
float hereShouldLevel = nowAccum - GameMath.MurmurHash3Mod(pos.X, 0, pos.Z, 150) / 300f;
float shouldIndexf = GameMath.Clamp(hereShouldLevel - 1.1f, -1, ws.GeneralConfig.SnowLayerBlocks.Count - 1);
int shouldIndex = shouldIndexf < 0 ? -1 : (int)shouldIndexf;
placePos.Set(pos.X, Math.Min(pos.Y + 1, sapi.World.BlockAccessor.MapSizeY - 1), pos.Z);
chunkY = placePos.Y / chunksize;
if (prevChunkY != chunkY)
{
chunk = chunksCol?[chunkY] ?? sapi.WorldManager.GetChunk(chunkX, chunkY, chunkZ);
prevChunkY = chunkY;
}
if (chunk == null)
{
return(null);
}
Block upBlock = chunk.GetLocalLiquidOrBlockAtBlockPos(sapi.World, placePos);
// Case 1: We have a block that can become snow covered (or more snow covered)
placePos.Set(pos);
Block newblock = block.GetSnowCoveredVariant(placePos, hereShouldLevel);
if (newblock != null)
{
if (block.Id != newblock.Id && upBlock.Replaceable > 6000)
{
updateChunk.SetBlocks[placePos.Copy()] = new BlockIdAndSnowLevel(newblock, hereShouldLevel);
}
}
// Case 2: We have a solid block that can have snow on top
else if (block.AllowSnowCoverage(sapi.World, placePos))
{
placePos.Set(pos.X, pos.Y + 1, pos.Z);
if (upBlock.Id != 0)
{
newblock = upBlock.GetSnowCoveredVariant(placePos, hereShouldLevel);
if (newblock != null && upBlock.Id != newblock.Id)
{
updateChunk.SetBlocks[placePos.Copy()] = new BlockIdAndSnowLevel(newblock, hereShouldLevel);
}
continue;
}
if (shouldIndex >= 0)
{
Block toPlaceBlock = layers.GetKeyAtIndex(shouldIndex);
updateChunk.SetBlocks[placePos.Copy()] = new BlockIdAndSnowLevel(toPlaceBlock, hereShouldLevel);
}
}
}
return(updateChunk);
}
