reactphysics3d/include/reactphysics3d/engine/Islands.h
2022-01-01 01:14:49 +01:00

171 lines
6.8 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2022 Daniel Chappuis *
*********************************************************************************
* *
* This software is provided 'as-is', without any express or implied warranty. *
* In no event will the authors be held liable for any damages arising from the *
* use of this software. *
* *
* Permission is granted to anyone to use this software for any purpose, *
* including commercial applications, and to alter it and redistribute it *
* freely, subject to the following restrictions: *
* *
* 1. The origin of this software must not be misrepresented; you must not claim *
* that you wrote the original software. If you use this software in a *
* product, an acknowledgment in the product documentation would be *
* appreciated but is not required. *
* *
* 2. Altered source versions must be plainly marked as such, and must not be *
* misrepresented as being the original software. *
* *
* 3. This notice may not be removed or altered from any source distribution. *
* *
********************************************************************************/
#ifndef REACTPHYSICS3D_ISLANDS_H
#define REACTPHYSICS3D_ISLANDS_H
// Libraries
#include <reactphysics3d/configuration.h>
#include <reactphysics3d/containers/Array.h>
#include <reactphysics3d/engine/Entity.h>
#include <reactphysics3d/constraint/Joint.h>
namespace reactphysics3d {
// Declarations
// Structure Islands
/**
* This class contains all the islands of bodies during a frame.
* An island represent an isolated group of awake bodies that are connected with each other by
* some contraints (contacts or joints).
*/
struct Islands {
private:
/// Number of islands in the previous frame
uint32 mNbIslandsPreviousFrame;
/// Number of items in the bodyEntities array in the previous frame
uint32 mNbBodyEntitiesPreviousFrame;
/// Maximum number of bodies in a single island in the previous frame
uint32 mNbMaxBodiesInIslandPreviousFrame;
/// Maximum number of bodies in a single island in the current frame
uint32 mNbMaxBodiesInIslandCurrentFrame;
public:
// -------------------- Attributes -------------------- //
/// For each island, index of the first contact manifold of the island in the array of contact manifolds
Array<uint> contactManifoldsIndices;
/// For each island, number of contact manifolds in the island
Array<uint> nbContactManifolds;
/// Array of all the entities of the bodies in the islands (stored sequentially)
Array<Entity> bodyEntities;
/// For each island we store the starting index of the bodies of that island in the "bodyEntities" array
Array<uint32> startBodyEntitiesIndex;
/// For each island, total number of bodies in the island
Array<uint32> nbBodiesInIsland;
// -------------------- Methods -------------------- //
/// Constructor
Islands(MemoryAllocator& allocator)
:mNbIslandsPreviousFrame(16), mNbBodyEntitiesPreviousFrame(32), mNbMaxBodiesInIslandPreviousFrame(0), mNbMaxBodiesInIslandCurrentFrame(0),
contactManifoldsIndices(allocator), nbContactManifolds(allocator),
bodyEntities(allocator), startBodyEntitiesIndex(allocator), nbBodiesInIsland(allocator) {
}
/// Destructor
~Islands() = default;
/// Assignment operator
Islands& operator=(const Islands& island) = delete;
/// Copy-constructor
Islands(const Islands& island) = default;
/// Return the number of islands
uint32 getNbIslands() const {
return static_cast<uint32>(contactManifoldsIndices.size());
}
/// Add an island and return its index
uint32 addIsland(uint32 contactManifoldStartIndex) {
const uint32 islandIndex = static_cast<uint32>(contactManifoldsIndices.size());
contactManifoldsIndices.add(contactManifoldStartIndex);
nbContactManifolds.add(0);
startBodyEntitiesIndex.add(static_cast<uint32>(bodyEntities.size()));
nbBodiesInIsland.add(0);
if (islandIndex > 0 && nbBodiesInIsland[islandIndex-1] > mNbMaxBodiesInIslandCurrentFrame) {
mNbMaxBodiesInIslandCurrentFrame = nbBodiesInIsland[islandIndex-1];
}
return islandIndex;
}
void addBodyToIsland(Entity bodyEntity) {
const uint32 islandIndex = static_cast<uint32>(contactManifoldsIndices.size());
assert(islandIndex > 0);
bodyEntities.add(bodyEntity);
nbBodiesInIsland[islandIndex - 1]++;
}
/// Reserve memory for the current frame
void reserveMemory() {
contactManifoldsIndices.reserve(mNbIslandsPreviousFrame);
nbContactManifolds.reserve(mNbIslandsPreviousFrame);
startBodyEntitiesIndex.reserve(mNbIslandsPreviousFrame);
nbBodiesInIsland.reserve(mNbIslandsPreviousFrame);
bodyEntities.reserve(mNbBodyEntitiesPreviousFrame);
}
/// Clear all the islands
void clear() {
const uint32 nbIslands = static_cast<uint32>(nbContactManifolds.size());
if (nbIslands > 0 && nbBodiesInIsland[nbIslands-1] > mNbMaxBodiesInIslandCurrentFrame) {
mNbMaxBodiesInIslandCurrentFrame = nbBodiesInIsland[nbIslands-1];
}
mNbMaxBodiesInIslandPreviousFrame = mNbMaxBodiesInIslandCurrentFrame;
mNbIslandsPreviousFrame = nbIslands;
mNbMaxBodiesInIslandCurrentFrame = 0;
mNbBodyEntitiesPreviousFrame = static_cast<uint32>(bodyEntities.size());
contactManifoldsIndices.clear(true);
nbContactManifolds.clear(true);
bodyEntities.clear(true);
startBodyEntitiesIndex.clear(true);
nbBodiesInIsland.clear(true);
}
uint32 getNbMaxBodiesInIslandPreviousFrame() const {
return mNbMaxBodiesInIslandPreviousFrame;
}
};
}
#endif