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Adapt unitMotion to edge-edge distance checks.

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D981/c219ee54b2 changed IsInXChecks to use edge-to-edge distance instead
of centre-to-edge, which broke UnitMotion's min-range movement, which
assumed distance to the center.

Since units are represented as squares, the diagonal point may be closer
to the target than the "real" clearance by a factor √2, so the delta
between minimum range and maximum range should be at least `(√2 - 1) *
clearance` to be safe in all situations (this is generally not a problem
for regular units which have a clearance of 0.8, but could be one for
catapults or elephants).

Differential Revision: https://code.wildfiregames.com/D1969
This was SVN commit r22422.
This commit is contained in:
wraitii 2019-07-01 19:50:06 +00:00
parent d2c88acf44
commit 44aef27b78
2 changed files with 12 additions and 16 deletions
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19
source/simulation2/components/CCmpUnitMotion.cpp
View File

@ -1421,16 +1421,19 @@ bool CCmpUnitMotion::MoveToPointRange(entity_pos_t x, entity_pos_t z, entity_pos
if (distance < minRange)
{
// Too close to target - move outwards to a circle
// that's slightly larger than the min range
// that's slightly larger than the min range.
goal.type = PathGoal::INVERTED_CIRCLE;
goal.hw = minRange + Pathfinding::GOAL_DELTA;
// Distance checks are nearest edge to nearest edge, so we need to account for our clearance
// and we must make sure diagonals also fit so multiply by slightly more than sqrt(2)
goal.hw = minRange + m_Clearance * 3 /2;
}
else if (maxRange >= entity_pos_t::Zero() && distance > maxRange)
{
// Too far from target - move inwards to a circle
// that's slightly smaller than the max range
goal.type = PathGoal::CIRCLE;
goal.hw = maxRange - Pathfinding::GOAL_DELTA;
goal.hw = maxRange;
// If maxRange was abnormally small,
// collapse the circle into a point
@ -1502,7 +1505,7 @@ bool CCmpUnitMotion::MoveToTargetRange(entity_id_t target, entity_pos_t minRange
/*
* If we're starting outside the maxRange, we need to move closer in.
* If we're starting inside the minRange, we need to move further out.
* These ranges are measured from the center of this entity to the edge of the target;
* These ranges are measured from the edge of this entity to the edge of the target;
* we add the goal range onto the size of the target shape to get the goal shape.
* (Then we extend it outwards/inwards by a little bit to be sure we'll end up
* within the right range, in case of minor numerical inaccuracies.)
@ -1544,7 +1547,9 @@ bool CCmpUnitMotion::MoveToTargetRange(entity_id_t target, entity_pos_t minRange
// Circumscribe the square
entity_pos_t circleRadius = halfSize.Length();
entity_pos_t goalDistance = minRange + Pathfinding::GOAL_DELTA;
// Distance checks are nearest edge to nearest edge, so we need to account for our clearance
// and we must make sure diagonals also fit so multiply by slightly more than sqrt(2)
entity_pos_t goalDistance = minRange + m_Clearance * 3 /2;
if (ShouldTreatTargetAsCircle(minRange, circleRadius))
{
@ -1592,7 +1597,7 @@ bool CCmpUnitMotion::MoveToTargetRange(entity_id_t target, entity_pos_t minRange
return true;
}
entity_pos_t goalDistance = maxRange - Pathfinding::GOAL_DELTA;
entity_pos_t goalDistance = maxRange;
goal.type = PathGoal::CIRCLE;
goal.hw = circleRadius + goalDistance;
@ -1602,7 +1607,7 @@ bool CCmpUnitMotion::MoveToTargetRange(entity_id_t target, entity_pos_t minRange
// The target is large relative to our range, so treat it as a square and
// get close enough that the diagonals come within range
entity_pos_t goalDistance = (maxRange - Pathfinding::GOAL_DELTA)*2 / 3; // multiply by slightly less than 1/sqrt(2)
entity_pos_t goalDistance = maxRange * 2 / 3; // multiply by slightly less than 1/sqrt(2)
goal.type = PathGoal::SQUARE;
goal.u = obstruction.u;

9
source/simulation2/helpers/Pathfinding.h
View File

@ -148,15 +148,6 @@ namespace Pathfinding
const int NAVCELL_SIZE_INT = 1;
const int NAVCELL_SIZE_LOG2 = 0;
/**
* For extending the goal outwards/inwards a little bit
* NOTE: keep next to the definition of NAVCELL_SIZE to avoid init order problems
* between translation units.
* TODO: figure out whether this is actually needed. It was added back in r8751 (in 2010) for unclear reasons
* and it does not seem to really improve behavior today
*/
const entity_pos_t GOAL_DELTA = NAVCELL_SIZE/8;
/**
* To make sure the long-range pathfinder is more strict than the short-range one,
* we need to slightly over-rasterize. So we extend the clearance radius by 1.