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Fix ActorMap spatial partitioning to actually work.

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The bin partitioning in ActorMap worked by dividing the map up into a few chunks of cells, each of which would contain some actors. Unfortunately, the bins were accessed directly in world coordinates which are on a scale 1024x greater than cell coordinates. This lead to all actors being placed into the bottom right bin. When checking for actors in a box, only this bottom right bin would be iterated for actors. Thanks to the fact this bin indeed contained all the actors, some clamps on the input ranges and filtering required per bin anyway, this actually returned correct results. Effectively, it was as if there was no spatial partitioning at all.

Not surprisingly however, this is fairly inefficient. By correcting the spatial partitioning to actually partition we see a 7x speedup in ActorsInBox on the RA shellmap.
This commit is contained in:
RoosterDragon
2015-01-04 02:31:58 +00:00
parent 9e0bd02e39
commit a0737ccbf3
1 changed files with 50 additions and 25 deletions
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75
OpenRA.Game/Traits/World/ActorMap.cs
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@@ -10,6 +10,7 @@
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
namespace OpenRA.Traits
@@ -179,12 +180,12 @@ namespace OpenRA.Traits
map = world.Map;
influence = new CellLayer<InfluenceNode>(world.Map);
cols = world.Map.MapSize.X / info.BinSize + 1;
rows = world.Map.MapSize.Y / info.BinSize + 1;
cols = CellCoordToBinIndex(world.Map.MapSize.X) + 1;
rows = CellCoordToBinIndex(world.Map.MapSize.Y) + 1;
bins = new Bin[rows * cols];
for (var j = 0; j < rows; j++)
for (var i = 0; i < cols; i++)
bins[j * cols + i] = new Bin();
for (var row = 0; row < rows; row++)
for (var col = 0; col < cols; col++)
bins[row * cols + col] = new Bin();
// Cache this delegate so it does not have to be allocated repeatedly.
actorShouldBeRemoved = removeActorPosition.Contains;
@@ -351,10 +352,10 @@ namespace OpenRA.Traits
foreach (var a in addActorPosition)
{
var pos = a.OccupiesSpace.CenterPosition;
var i = (pos.X / info.BinSize).Clamp(0, cols - 1);
var j = (pos.Y / info.BinSize).Clamp(0, rows - 1);
var bin = bins[j * cols + i];
var pos = a.CenterPosition;
var col = WorldCoordToBinIndex(pos.X).Clamp(0, cols - 1);
var row = WorldCoordToBinIndex(pos.Y).Clamp(0, rows - 1);
var bin = BinAt(row, col);
bin.Actors.Add(a);
foreach (var t in bin.ProximityTriggers)
@@ -460,20 +461,44 @@ namespace OpenRA.Traits
addActorPosition.Add(a);
}
int CellCoordToBinIndex(int cell)
{
return cell / info.BinSize;
}
int WorldCoordToBinIndex(int world)
{
return CellCoordToBinIndex(world / 1024);
}
Rectangle BinRectangleCoveringWorldArea(int worldLeft, int worldTop, int worldRight, int worldBottom)
{
var minCol = WorldCoordToBinIndex(worldLeft).Clamp(0, cols - 1);
var minRow = WorldCoordToBinIndex(worldTop).Clamp(0, rows - 1);
var maxCol = WorldCoordToBinIndex(worldRight).Clamp(0, cols - 1);
var maxRow = WorldCoordToBinIndex(worldBottom).Clamp(0, rows - 1);
return Rectangle.FromLTRB(minCol, minRow, maxCol, maxRow);
}
Bin BinAt(int binRow, int binCol)
{
return bins[binRow * cols + binCol];
}
IEnumerable<Bin> BinsInBox(WPos a, WPos b)
{
var left = Math.Min(a.X, b.X);
var top = Math.Min(a.Y, b.Y);
var right = Math.Max(a.X, b.X);
var bottom = Math.Max(a.Y, b.Y);
var i1 = (left / info.BinSize).Clamp(0, cols - 1);
var i2 = (right / info.BinSize).Clamp(0, cols - 1);
var j1 = (top / info.BinSize).Clamp(0, rows - 1);
var j2 = (bottom / info.BinSize).Clamp(0, rows - 1);
for (var j = j1; j <= j2; j++)
for (var i = i1; i <= i2; i++)
yield return bins[j * cols + i];
var region = BinRectangleCoveringWorldArea(left, top, right, bottom);
var minCol = region.Left;
var minRow = region.Top;
var maxCol = region.Right;
var maxRow = region.Bottom;
for (var row = minRow; row <= maxRow; row++)
for (var col = minCol; col <= maxCol; col++)
yield return BinAt(row, col);
}
public IEnumerable<Actor> ActorsInBox(WPos a, WPos b)
@@ -482,16 +507,16 @@ namespace OpenRA.Traits
var top = Math.Min(a.Y, b.Y);
var right = Math.Max(a.X, b.X);
var bottom = Math.Max(a.Y, b.Y);
var i1 = (left / info.BinSize).Clamp(0, cols - 1);
var i2 = (right / info.BinSize).Clamp(0, cols - 1);
var j1 = (top / info.BinSize).Clamp(0, rows - 1);
var j2 = (bottom / info.BinSize).Clamp(0, rows - 1);
for (var j = j1; j <= j2; j++)
var region = BinRectangleCoveringWorldArea(left, top, right, bottom);
var minCol = region.Left;
var minRow = region.Top;
var maxCol = region.Right;
var maxRow = region.Bottom;
for (var row = minRow; row <= maxRow; row++)
{
for (var i = i1; i <= i2; i++)
for (var col = minCol; col <= maxCol; col++)
{
foreach (var actor in bins[j * cols + i].Actors)
foreach (var actor in BinAt(row, col).Actors)
{
if (actor.IsInWorld)
{