koobas.hobune.stream
What's with this absurd index array input?
I made the following script:
public Block GetBlock(int x, int y, int z)
{
int a = x / 10; int b = y / 10; int c = z / 10;
int lowX = x % 10; int lowY = y % 10; int lowZ = z % 10;
Block block;
if(chunkList.ContainsKey(new Vector3(a, b, c)))
{
Debug.Log("Loaded Coords " + lowX + " " + lowY + " " + lowZ);
block = chunkList[new Vector3(a, b, c)].GetComponent<Chunk>().blockList[lowX, lowY, lowZ];
}
else
{
block = new BlockAir();
}
return block;
}
As you can see I debugged the coordinates and for some absurd reason this input springs up and starts hurling errors at my face.
Loaded Coordinates (9, 4, -1)
I understand that the error is due -1 not being reachable for not existing in array, but where does it come from? As far as I can tell whatever the input it should always return positive values...
You're right to expect that but apparently that's not how it works. See the top 2 answers for an explanation and a possible solution.
Also be aware of an integer division rounds towards 0 and not always down. So 3/10 is "0" 13/10 is "1". However (-3) / 10 is also "0" and (-13)/10 is "-1". You most likely want to get -1 for (-3)/10 and -2 for (-13)/10. That's why you should either use only positive values or use the proper rounding:
The most common way would be:
public Block GetBlock(Vector3 pos)
{
// chunk coordinates
int x = $$anonymous$$athf.FloorToInt(pos.x / 10f);
int y = $$anonymous$$athf.FloorToInt(pos.y / 10f);
int z = $$anonymous$$athf.FloorToInt(pos.z / 10f);
// chunk local coordinates, always positive
pos -= new Vector3(x, y, z)*10;
So for example the value "-3.25" for for pos.x would yield a chunk x coordinate of "-1" and "pos.x" would become "7.25". By flooring or just int casting the resulting pos you get the block coordinate (7). In turn subtracting the block coordinate from pos you get the fractional position inside the block. (0.25)
