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| author | Perttu Ahola <celeron55@gmail.com> | 2010-12-01 15:20:12 +0200 |
|---|---|---|
| committer | Perttu Ahola <celeron55@gmail.com> | 2010-12-01 15:20:12 +0200 |
| commit | 5e0c284f3a8debdd9ebb080f80e36dceb7bc4ce2 (patch) | |
| tree | d9c4f61f491b57ad7b84df0925186e2183da140b /src/main.cpp | |
| parent | 38353751c9f4e03fb6a0b855e6d8b5691af71dc0 (diff) | |
| download | minetest-5e0c284f3a8debdd9ebb080f80e36dceb7bc4ce2.tar.gz minetest-5e0c284f3a8debdd9ebb080f80e36dceb7bc4ce2.tar.bz2 minetest-5e0c284f3a8debdd9ebb080f80e36dceb7bc4ce2.zip | |
some work-in-progress water stuff
Diffstat (limited to 'src/main.cpp')
| -rw-r--r-- | src/main.cpp | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/main.cpp b/src/main.cpp index 677f03843..938eb14ef 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -81,6 +81,9 @@ SUGGESTION: Use same technique for sector heightmaps as what we're using for UnlimitedHeightmap? (getting all neighbors
when generating)
+TODO: Proper handling of spawning place (try to find something that
+ is not in the middle of an ocean (some land to stand on at
+ least) and save it in map config.
SUGG: Set server to automatically find a good spawning place in some
place where there is water and land.
- Map to have a getWalkableNear(p)
@@ -176,6 +179,197 @@ TODO: MovingObject::move and Player::move are basically the same. Doing now:
======================================================================
+Water dynamics pseudo-code (block = MapNode):
+SUGG: Create separate flag table in VoxelManipulator to allow fast
+clearing of "modified" flags
+
+neighborCausedPressure(pos):
+ pressure = 0
+ dirs = {down, left, right, back, front, up}
+ for d in dirs:
+ pos2 = pos + d
+ p = block_at(pos2).pressure
+ if d.Y == 1 and p > min:
+ p -= 1
+ if d.Y == -1 and p < max:
+ p += 1
+ if p > pressure:
+ pressure = p
+ return pressure
+
+# This should somehow update all changed pressure values
+# in an unknown body of water
+updateWaterPressure(pos):
+ TODO
+
+FIXME: This goes in an indefinite loop when there is an underwater
+chamber like this:
+
+#111######
+#222##22##
+#33333333x<- block removed from here
+##########
+
+#111######
+#222##22##
+#3333333x1
+##########
+
+#111######
+#222##22##
+#333333x11
+##########
+
+#111######
+#222##2x##
+#333333333
+##########
+
+#111######
+#222##x2##
+#333333333
+##########
+
+Now, consider moving to the last block not allowed.
+
+Consider it a 3D case with a depth of 2. We're now at this situation.
+Note the additional blocking ## in the second depth plane.
+
+z=1 z=2
+#111###### #111######
+#222##x2## #222##22##
+#333333333 #33333##33
+########## ##########
+
+#111###### #111######
+#222##22## #222##x2##
+#333333333 #33333##33
+########## ##########
+
+#111###### #111######
+#222##22## #222##2x##
+#333333333 #33333##33
+########## ##########
+
+Now there is nowhere to go, without going to an already visited block,
+but the pressure calculated in here from neighboring blocks is >= 2,
+so it is not the final ending.
+
+We will back up to a state where there is somewhere to go to.
+It is this state:
+
+#111###### #111######
+#222##22## #222##22##
+#333333x33 #33333##33
+########## ##########
+
+Then just go on, avoiding already visited blocks:
+
+#111###### #111######
+#222##22## #222##22##
+#33333x333 #33333##33
+########## ##########
+
+#111###### #111######
+#222##22## #222##22##
+#3333x3333 #33333##33
+########## ##########
+
+#111###### #111######
+#222##22## #222##22##
+#333x33333 #33333##33
+########## ##########
+
+#111###### #111######
+#222##22## #222##22##
+#33x333333 #33333##33
+########## ##########
+
+#111###### #111######
+#22x##22## #222##22##
+#333333333 #33333##33
+########## ##########
+
+#11x###### #111######
+#222##22## #222##22##
+#333333333 #33333##33
+########## ##########
+
+"Blob". the air bubble finally got out of the water.
+Then return recursively to a state where there is air next to water,
+clear the visit flags and feed the neighbor of the water recursively
+to the algorithm.
+
+#11 ###### #111######
+#222##22## #222##22##
+#333333333x #33333##33
+########## ##########
+
+#11 ###### #111######
+#222##22## #222##22##
+#33333333x3 #33333##33
+########## ##########
+
+...and so on.
+
+
+# removed_pos: a position that has been changed from something to air
+flowWater(removed_pos):
+ dirs = {top, left, right, back, front, bottom}
+ selected_dir = None
+ for d in dirs:
+ b2 = removed_pos + d
+
+ # Ignore positions that don't have water
+ if block_at(b2) != water:
+ continue
+
+ # Ignore positions that have already been checked
+ if block_at(b2).checked:
+ continue
+
+ # If block is at top, select it always.
+ if d.Y == 1:
+ selected_dir = d
+ break
+
+ # If block is at bottom, select it if it has enough pressure.
+ # >= 3 needed for stability (and sanity)
+ if d.Y == -1:
+ if block_at(b2).pressure >= 3:
+ selected_dir = d
+ break
+ continue
+
+ # Else block is at some side. select it if it has enough pressure.
+ if block_at(b2).pressure >= 2:
+ selected_dir = d
+ break
+
+ # If there is nothing to do anymore, return.
+ if selected_dir == None
+ return
+
+ b2 = removed_pos + selected_dir
+
+ # Move block
+ set_block(removed_pos, block_at(b2))
+ set_block(b2, air_block)
+
+ # Update pressure
+ updateWaterPressure(removed_pos)
+
+ # Flow water to the newly created empty position
+ flowWater(b2)
+
+ # Check empty positions around and try flowing water to them
+ for d in dirs:
+ b3 = removed_pos + d
+ # Ignore positions that are not air
+ if block_at(b3) is not air:
+ continue
+ flowWater(b3)
+
======================================================================
|