reactphysics3d/src/components/TransformComponents.cpp
2019-03-16 08:40:50 +01:00

153 lines
6.2 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2018 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. *
* *
********************************************************************************/
// Libraries
#include "TransformComponents.h"
#include "engine/EntityManager.h"
#include <cassert>
#include <random>
// We want to use the ReactPhysics3D namespace
using namespace reactphysics3d;
// Constructor
TransformComponents::TransformComponents(MemoryAllocator& allocator)
:Components(allocator, sizeof(Entity) + sizeof(Transform)) {
// Allocate memory for the components data
allocate(INIT_NB_ALLOCATED_COMPONENTS);
}
// Allocate memory for a given number of components
void TransformComponents::allocate(uint32 nbComponentsToAllocate) {
assert(nbComponentsToAllocate > mNbAllocatedComponents);
// Size for the data of a single component (in bytes)
const size_t totalSizeBytes = nbComponentsToAllocate * mComponentDataSize;
// Allocate memory
void* newBuffer = mMemoryAllocator.allocate(totalSizeBytes);
assert(newBuffer != nullptr);
// New pointers to components data
Entity* newEntities = static_cast<Entity*>(newBuffer);
Transform* newTransforms = reinterpret_cast<Transform*>(newEntities + nbComponentsToAllocate);
// If there was already components before
if (mNbComponents > 0) {
// Copy component data from the previous buffer to the new one
memcpy(newTransforms, mTransforms, mNbComponents * sizeof(Transform));
memcpy(newEntities, mBodies, mNbComponents * sizeof(Entity));
// Deallocate previous memory
mMemoryAllocator.release(mBuffer, mNbAllocatedComponents * mComponentDataSize);
}
mBuffer = newBuffer;
mBodies = newEntities;
mTransforms = newTransforms;
mNbAllocatedComponents = nbComponentsToAllocate;
}
// Add a component
void TransformComponents::addComponent(Entity bodyEntity, bool isSleeping, const TransformComponent& component) {
// Prepare to add new component (allocate memory if necessary and compute insertion index)
uint32 index = prepareAddComponent(isSleeping);
// Insert the new component data
new (mBodies + index) Entity(bodyEntity);
new (mTransforms + index) Transform(component.transform);
// Map the entity with the new component lookup index
mMapEntityToComponentIndex.add(Pair<Entity, uint32>(bodyEntity, index));
mNbComponents++;
assert(mDisabledStartIndex <= mNbComponents);
assert(mNbComponents == static_cast<uint32>(mMapEntityToComponentIndex.size()));
}
// Move a component from a source to a destination index in the components array
// The destination location must contain a constructed object
void TransformComponents::moveComponentToIndex(uint32 srcIndex, uint32 destIndex) {
const Entity entity = mBodies[srcIndex];
// Copy the data of the source component to the destination location
new (mBodies + destIndex) Entity(mBodies[srcIndex]);
new (mTransforms + destIndex) Transform(mTransforms[srcIndex]);
// Destroy the source component
destroyComponent(srcIndex);
assert(!mMapEntityToComponentIndex.containsKey(entity));
// Update the entity to component index mapping
mMapEntityToComponentIndex.add(Pair<Entity, uint32>(entity, destIndex));
assert(mMapEntityToComponentIndex[mBodies[destIndex]] == destIndex);
}
// Swap two components in the array
void TransformComponents::swapComponents(uint32 index1, uint32 index2) {
// Copy component 1 data
Entity entity1(mBodies[index1]);
Transform transform1(mTransforms[index1]);
// Destroy component 1
destroyComponent(index1);
moveComponentToIndex(index2, index1);
// Reconstruct component 1 at component 2 location
new (mBodies + index2) Entity(entity1);
new (mTransforms + index2) Transform(transform1);
// Update the entity to component index mapping
mMapEntityToComponentIndex.add(Pair<Entity, uint32>(entity1, index2));
assert(mMapEntityToComponentIndex[mBodies[index1]] == index1);
assert(mMapEntityToComponentIndex[mBodies[index2]] == index2);
assert(mNbComponents == static_cast<uint32>(mMapEntityToComponentIndex.size()));
}
// Destroy a component at a given index
void TransformComponents::destroyComponent(uint32 index) {
Components::destroyComponent(index);
assert(mMapEntityToComponentIndex[mBodies[index]] == index);
mMapEntityToComponentIndex.remove(mBodies[index]);
mBodies[index].~Entity();
mTransforms[index].~Transform();
}