1
0
forked from 0ad/0ad
0ad/source/simulation2/components/ICmpObstruction.h
wraitii 592453c62f Add a simple 'pushing' logic to unit motion to improve movement.
This implements a form of crowd movement that I've generally called
'unit pushing' in the last few years.
Essentially, any two units will push each other away when they're too
close. This makes it possible to ignore unit-unit obstructions, and thus
makes movement much smoother in crowds.
This first iteration of this system only allows pushing between idle
units and between moving units (i.e. a moving unit does not affect an
idle one).
This is because the unitMotion logic to detect it is stuck & needs to
use the pathfinders starts breaking: units can fail to move because they
are pushed away from their intended movement, and the current logic
fails to handle this gracefully.
Thankfully, the most value of this patch in terms of player experience
is found in the improvements to group movements and shuttling.

Other impacts:
- As the short pathfinder is called less often, we can increase the
starting search range & reduce the # of max turns, both improving
collision recovery.
- The performance of idle units is slightly worsened, as they must be
checked for idle-idle collisions. If needed a 'sleeping' system, as used
in physics engine, could be implemented.
- In general, however, expect slight performance improvements, as fewer
short paths are computed.
- Gathering efficiency should increase slightly, since shuttling times
are likely reduced slightly.
- As a sanity change to improve some edge cases (units that say they're
moving, i.e. pushable, but don't actually move), the 'going straight'
logic is turned off if a short path has been computed. This requires a
few cascading changes to work correctly.

Technical notes:
- To reduce the cost of the n^2 comparisons that pushing requires, units
are only compared within a small square on a grid which is lazily
reconstructed each turn. The overhead seems rather small, and this is
much simpler than keeping an up-to-date grid.
- The design is intended to be parallelisable if needed someday.
- The pathfinder's CheckMovement ignores moving units in UnitMotion, as
that is now the spec. Idle units are not ignored, which is required for
the 'collision' detection to work correctly (see above).

Refs #3442 (not fixed - idle units are not pushed by moving units).
Fixes #5084 (the overlap can still happen, but units will push each
other away).

Differential Revision: https://code.wildfiregames.com/D1490
This was SVN commit r25182.
2021-04-02 16:30:59 +00:00

163 lines
5.4 KiB
C++

/* Copyright (C) 2021 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef INCLUDED_ICMPOBSTRUCTION
#define INCLUDED_ICMPOBSTRUCTION
#include "simulation2/system/Interface.h"
#include "simulation2/components/ICmpObstructionManager.h"
/**
* Flags an entity as obstructing movement for other units,
* and handles the processing of collision queries.
*/
class ICmpObstruction : public IComponent
{
public:
enum EFoundationCheck {
FOUNDATION_CHECK_SUCCESS,
FOUNDATION_CHECK_FAIL_ERROR,
FOUNDATION_CHECK_FAIL_NO_OBSTRUCTION,
FOUNDATION_CHECK_FAIL_OBSTRUCTS_FOUNDATION,
FOUNDATION_CHECK_FAIL_TERRAIN_CLASS
};
enum EObstructionType {
STATIC,
UNIT,
CLUSTER
};
virtual ICmpObstructionManager::tag_t GetObstruction() const = 0;
/**
* Gets the square corresponding to this obstruction shape.
* @return true and updates @p out on success;
* false on failure (e.g. object not in the world).
*/
virtual bool GetObstructionSquare(ICmpObstructionManager::ObstructionSquare& out) const = 0;
/**
* Same as the method above, but returns an obstruction shape for the previous turn
*/
virtual bool GetPreviousObstructionSquare(ICmpObstructionManager::ObstructionSquare& out) const = 0;
/**
* @return the size of the obstruction (either the clearance or a circumscribed circle).
*/
virtual entity_pos_t GetSize() const = 0;
/**
* @return the size of the static obstruction or (0,0) for a unit shape.
*/
virtual CFixedVector2D GetStaticSize() const = 0;
virtual EObstructionType GetObstructionType() const = 0;
virtual void SetUnitClearance(const entity_pos_t& clearance) = 0;
virtual bool IsControlPersistent() const = 0;
/**
* Test whether the front of the obstruction square is in the water and the back is on the shore.
*/
virtual bool CheckShorePlacement() const = 0;
/**
* Test whether this entity is colliding with any obstruction that are set to
* block the creation of foundations.
* @param ignoredEntities List of entities to ignore during the test.
* @return FOUNDATION_CHECK_SUCCESS if check passes, else an EFoundationCheck
* value describing the type of failure.
*/
virtual EFoundationCheck CheckFoundation(const std::string& className) const = 0;
virtual EFoundationCheck CheckFoundation(const std::string& className, bool onlyCenterPoint) const = 0;
/**
* CheckFoundation wrapper for script calls, to return friendly strings instead of an EFoundationCheck.
* @return "success" if check passes, else a string describing the type of failure.
*/
virtual std::string CheckFoundation_wrapper(const std::string& className, bool onlyCenterPoint) const;
/**
* Test whether this entity is colliding with any obstructions that share its
* control groups and block the creation of foundations.
* @return true if foundation is valid (not obstructed)
*/
virtual bool CheckDuplicateFoundation() const = 0;
/**
* Returns a list of entities that have an obstruction matching the given flag and intersect the current obstruction.
* @return vector of blocking entities
*/
virtual std::vector<entity_id_t> GetEntitiesByFlags(ICmpObstructionManager::flags_t flags) const = 0;
/**
* Returns a list of entities that are blocking movement.
* @return vector of blocking entities
*/
virtual std::vector<entity_id_t> GetEntitiesBlockingMovement() const = 0;
/**
* Returns a list of entities that are blocking construction of a foundation.
* @return vector of blocking entities
*/
virtual std::vector<entity_id_t> GetEntitiesBlockingConstruction() const = 0;
/**
* Returns a list of entities that shall be deleted when a construction on this obstruction starts,
* for example sheep carcasses.
*/
virtual std::vector<entity_id_t> GetEntitiesDeletedUponConstruction() const = 0;
/**
* Detects collisions between foundation-blocking entities and
* tries to fix them by setting control groups, if appropriate.
*/
virtual void ResolveFoundationCollisions() const = 0;
virtual void SetActive(bool active) = 0;
virtual void SetMovingFlag(bool enabled) = 0;
virtual void SetDisableBlockMovementPathfinding(bool movementDisabled, bool pathfindingDisabled, int32_t shape) = 0;
/**
* @param templateOnly - whether to return the raw template value or the current value.
*/
virtual bool GetBlockMovementFlag(bool templateOnly) const = 0;
/**
* Change the control group that the entity belongs to.
* Control groups are used to let units ignore collisions with other units from
* the same group. Default is the entity's own ID.
*/
virtual void SetControlGroup(entity_id_t group) = 0;
/// See SetControlGroup.
virtual entity_id_t GetControlGroup() const = 0;
virtual void SetControlGroup2(entity_id_t group2) = 0;
virtual entity_id_t GetControlGroup2() const = 0;
DECLARE_INTERFACE_TYPE(Obstruction)
};
#endif // INCLUDED_ICMPOBSTRUCTION