Skip to content

Commit

Permalink
General Work
Browse files Browse the repository at this point in the history 
- New traversal conditions
- D* Lite fully supports replanning
- Updated README with working advanced implementation
  • Loading branch information
@Suficio
Suficio committed Sep 12, 2019
1 parent 6df8753 commit 3901c82
Show file tree
Hide file tree
Showing 7 changed files with 141 additions and 61 deletions.
10 changes: 10 additions & 0 deletions DefaultConditions/predecessorconditions.json
View file
Original file line number Diff line number Diff line change
Expand Up @@ -162,5 +162,15 @@

]}
]}
]},
{"type":"blockconditions","coordinates":[1,3,0],"conditions":[

{"type":"nc_condition","coordinates":[1,2,0],"condition":"block"},
{"type":"nc_condition","coordinates":[0,3,0],"condition":"empty"},
{"type":"nc_condition","coordinates":[0,4,0],"condition":"empty"},

{"type":"condition","coordinates":[0,2,0],"condition":"empty"},
{"type":"condition","coordinates":[1,3,0],"condition":"empty"},
{"type":"condition","coordinates":[1,4,0],"condition":"empty"}
]}
]
10 changes: 10 additions & 0 deletions DefaultConditions/successorconditions.json
View file
Original file line number Diff line number Diff line change
Expand Up @@ -156,5 +156,15 @@
]}
]}
]}
]},
{"type":"blockconditions","coordinates":[1,-3,0],"conditions":[

{"type":"nc_condition","coordinates":[1,-4,0],"condition":"block"},
{"type":"nc_condition","coordinates":[1,-3,0],"condition":"empty"},
{"type":"nc_condition","coordinates":[1,-2,0],"condition":"empty"},
{"type":"nc_condition","coordinates":[1,-1,0],"condition":"empty"},

{"type":"condition","coordinates":[1,0,0],"condition":"empty"},
{"type":"condition","coordinates":[1,1,0],"condition":"empty"}
]}
]
1 change: 1 addition & 0 deletions Pathfinders/ASTAR.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,7 @@ module.exports = function(bot, sp, ep)
path.push(state.c);
}
returnState.path = path;
returnState.closestPoint = state.c;
})
.catch(function(e) {console.error('ERROR Pathfinder:', e);});
}
Expand Down
146 changes: 101 additions & 45 deletions Pathfinders/DLITE.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,14 +21,14 @@ module.exports = function(bot, sp, ep)
// First part of Main() in D*Lite
if (S.start === S.goal) return undefined;

let minState = null;
let minState;
let minCost = Number.POSITIVE_INFINITY;

// Get successors according to stored state.
const successors = bot.pathfinder.getSuccessors(S.start.c);
for (let n = 0, len = successors.length; n < len; n++)
{
const sp = ExistingState(successors[n]);
const sp = new State(successors[n]);
if (sp)
{
const cost = bot.pathfinder.COST(S.start.c, sp.c) + sp.g;
Expand All @@ -42,23 +42,35 @@ module.exports = function(bot, sp, ep)

return minState;
}

this.path.peek = function()
{
const temp = _peek();
if (temp !== undefined)
return temp.c;
else return undefined;
else return;
};

let globalMinCost = Number.POSITIVE_INFINITY;
this.path.pop = function()
{
const temp = _peek();
if (temp !== undefined)
{
const cost = bot.pathfinder.COST(S.start.c, temp.c) + temp.g;
if (cost >= globalMinCost) return;

globalMinCost = cost;
S.start = temp;

k_m = k_m + bot.pathfinder.HEURISTIC(S.last.c, S.start.c);
S.last = S.start;

return temp.c;
}
else return undefined;
else return;
};

this.path.replan = function(c)
{
return new Promise(function(resolve, reject)
Expand All @@ -83,50 +95,97 @@ module.exports = function(bot, sp, ep)
reject(e);
});
});
/* const v = ReturnState.OBSOLETE.pop();
if (v)
{
k_m = k_m + bot.pathfinder.HEURISTIC(S.last.c, S.start.c);
S.last = S.start;
};

// Changes in world state are passed to this function
this.path.updateState = function(c)
{
// Check if state or any predecessors of the state are part of the pathfinder state
let existsInState = false;
const predecessors = bot.pathfinder.getPredecessors(c);

// Since the blockUpdate event is only validated when a previously navigable vertex is blocked
// we need to only accomodate for one case. [c_old < c(u,v)]
const predecessors = bot.pathfinder.getPredecessors(v.c);
for (let n = 0, len = predecessors.length; n < len; n++)
if (S.check(c))
existsInState = true;

else
{
for (let m = 0, len = predecessors.length; m < len; m++)
{
const u = new State(predecessors[n]);
if (floatEqual(u.rhs, bot.pathfinder.COST(u.c, v.c) + v.g) && u !== S.goal)
if (S.check(predecessors[m]))
{
u.rhs = Number.POSITIVE_INFINITY;
const successors = bot.pathfinder.getSuccessors(u.c);
for (let m = 0, len = successors.length; m < len; m++)
{
const sp = new State(successors[m]);
const cost = bot.pathfinder.COST(u.c, sp.c) + sp.g;
if (u.rhs > cost) u.rhs = cost;
}
existsInState = true;
break;
}
}
}

if (!existsInState)
return;

// Updated block is relevant to pathfinder state
// Check if state is blocked or can traverse

// Usually a block above the state might be blocking it, this performs a check for a block right below
// it as either one or the other will be traversable. c0 is considered the relevant state position.

updateVertex(u);
let traversable = false;
let c0 = c;
const c1 = c.offset(0, -1, 0);

outer: for (let m = 0, len = predecessors.length; m < len; m++)
{
const successors = bot.pathfinder.getSuccessors(predecessors[m]);
for (let n = 0, len = successors.length; n < len; n++)
{
if (c0.equals(successors[n]))
{
traversable = true;
break outer;
}
else if (c1.equals(successors[n]))
{
c0 = c1;
traversable = true;
break outer;
}
}
}

// Updates state

computeShortestPath().then(ResolveFunction);
if (traversable)
{
const v = new State(c0);
predecessors.unshift(v.c); // Introduce v to state
}
else
{
if (!S.check(c0))
c0 = c1;
}
else computeShortestPath().then(ResolveFunction);*/
};

// Handles changes in the world state
/* bot.on('blockUpdate', function(_, newBlock)
{
const v = ExistingState(newBlock.position);
if (v && compareKeys(v.k, S.start.k)) // Ensures we havent already passed that block
for (let n = 0, len = predecessors.length; n < len; n++)
{
ReturnState.OBSOLETE.push(v);
U.remove(U.check(v));
S[v.c.x >>> 0][v.c.y >>> 0][v.c.z >>> 0] = undefined;
const u = new State(predecessors[n]);

if (u !== S.goal)
{
u.rhs = Number.POSITIVE_INFINITY;

const successors = bot.pathfinder.getSuccessors(u.c);
for (let m = 0, len = successors.length; m < len; m++)
{
const sp = new State(successors[m]);
const cost = bot.pathfinder.COST(u.c, sp.c) + sp.g;
if (u.rhs > cost) u.rhs = cost;
}
}

updateVertex(u);
}
}); */

return returnState.path.replan(bot.entity.position.floored());
};
};

// Global state functions
Expand Down Expand Up @@ -156,6 +215,10 @@ module.exports = function(bot, sp, ep)
}
} return false;
};
S.remove = function(c)
{
this[c.x >>> 0][c.y >>> 0][c.z >>> 0] = undefined;
};

// Priority queue functions
const U = new Heap(function(s1, s2) {return compareKeys(s1.k, s2.k);});
Expand Down Expand Up @@ -201,13 +264,6 @@ module.exports = function(bot, sp, ep)
}
}

function ExistingState(c)
{
if (S.check(c))
return S[c.x >>> 0][c.y >>> 0][c.z >>> 0];
else return undefined;
}

// Algorithm functions
function calculateKey(s)
{
Expand Down Expand Up @@ -261,7 +317,7 @@ module.exports = function(bot, sp, ep)
u.g = Number.POSITIVE_INFINITY;

const predecessors = bot.pathfinder.getPredecessors(u.c);
predecessors.push(u.c); // ∪ {u}
predecessors.unshift(u.c); // ∪ {u}
for (let n = 0, len = predecessors.length; n < len; n++)
{
const s = new State(predecessors[n]);
Expand Down
7 changes: 2 additions & 5 deletions Pathfinders/README.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ Object with the following properties:
### ASTARReturnState.ENUMState
Set when algorithim completes path search, equal to one of `bot.pathfinder.ENUMStatus` depending on whether the path search was successfull or not.

### ASTARReturnState.ClosestPoint
### ASTARReturnState.closestPoint
Set when algorithim the path search is incomplete, equal to the furthest position the bot could find a path to.

## D* Lite Pathfinding
Expand All @@ -53,10 +53,7 @@ Object with the following properties:
### DLITEReturnState.ENUMState
Set when algorithim completes path search, equal to one of `bot.pathfinder.ENUMStatus` depending on whether the path search was successful or not.

### DLITEReturnState.ClosestPoint
Set when algorithim completes path search, equal to the closest point from which a path from the end point to the start could be found.

If `DLITEReturnState.ENUMState` is incomplete, it is recommended to use a different method to navigate the bot to the `DLITEReturnState.ClosestPoint` before attempting pathfinding using D* Lite again.
If `DLITEReturnState.ENUMState` is incomplete, it is recommended to use a different method to find the nearest valid point to navigate from.

#### DLITEReturnState.path.pop()
As the path is determined while the bot moves across it, pop must be used to determine the next location to move to.
Expand Down
26 changes: 16 additions & 10 deletions README.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,32 +100,38 @@ bot.on('chat', function(username, message)
if (moveReturn === bot.move.ENUMStatus.Arrived)
{
if (endPoint.equals(position))
bot.chat('I\'ve arrived!');
resolve(position);

// Checks if bot hasnt moved since last replan.
// Checks if bot hasnt moved since last replan
// This does not mean there is no path, the bot could have fallen off its know state and should rescan with a new state.
else if (lastPoint && lastPoint.equals(position))
bot.chat('I\'ve been blocked!');
resolve(position);

else
{
lastPoint = position;
returnState.path.replan(position).then(move);
bot.pathfind.to(position, endPoint, bot.pathfinder.ENUMPathfinder.DLITE).then(move);
}
}
else
{
lastPoint = position;
returnState.path.replan(position).then(move);
bot.pathfind.to(position, endPoint, bot.pathfinder.ENUMPathfinder.DLITE).then(move);
}
});
}

bot.pathfinder.to(
bot.entity.position,
endPoint,
bot.pathfind.ENUMPathfinder.DLITE
).then(move);
bot.pathfind
.to(bot.entity.position, endPoint)
.then(function(returnState)
{
if (returnState.ENUMState === bot.pathfinder.ENUMStatus.Incomplete)
endPoint = returnState.closestPoint;

bot.pathfind
.to(bot.entity.position, endPoint, bot.pathfinder.ENUMPathfinder.DLITE)
.then(move);
});
}
});
```
Expand Down
2 changes: 1 addition & 1 deletion index.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,7 @@ module.exports = function(bot)

// Setup variables

bot.pathfinder.MAX_EXPANSIONS = 100000; // 10000
bot.pathfinder.MAX_EXPANSIONS = 10000; // 10000
bot.pathfinder.HEURISTIC = function(p1, p2) {return p1.distanceTo(p2);};
bot.pathfinder.COST = bot.pathfinder.HEURISTIC;

Expand Down

0 comments on commit 3901c82

Please sign in to comment.