You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
openmw-tes3mp/apps/openmw/mwphysics/heightfield.cpp

119 lines
3.8 KiB
C++

#include "heightfield.hpp"
#include "mtphysics.hpp"
#include <osg/Object>
#include <BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h>
#include <BulletCollision/CollisionDispatch/btCollisionObject.h>
#include <LinearMath/btTransform.h>
#include <type_traits>
#if BT_BULLET_VERSION < 310
// Older Bullet versions only support `btScalar` heightfields.
// Our heightfield data is `float`.
//
// These functions handle conversion from `float` to `double` when
// `btScalar` is `double` (`BT_USE_DOUBLE_PRECISION`).
namespace
{
template <class T>
auto makeHeights(const T* heights, float sqrtVerts)
-> std::enable_if_t<std::is_same<btScalar, T>::value, std::vector<btScalar>>
{
return {};
}
template <class T>
auto makeHeights(const T* heights, float sqrtVerts)
-> std::enable_if_t<!std::is_same<btScalar, T>::value, std::vector<btScalar>>
{
return std::vector<btScalar>(heights, heights + static_cast<std::ptrdiff_t>(sqrtVerts * sqrtVerts));
}
template <class T>
auto getHeights(const T* floatHeights, const std::vector<btScalar>&)
-> std::enable_if_t<std::is_same<btScalar, T>::value, const btScalar*>
{
return floatHeights;
}
template <class T>
auto getHeights(const T*, const std::vector<btScalar>& btScalarHeights)
-> std::enable_if_t<!std::is_same<btScalar, T>::value, const btScalar*>
{
return btScalarHeights.data();
}
}
#endif
namespace MWPhysics
{
HeightField::HeightField() {}
HeightField::HeightField(const HeightField&, const osg::CopyOp&) {}
HeightField::HeightField(const float* heights, int x, int y, float triSize, float sqrtVerts, float minH, float maxH, const osg::Object* holdObject, PhysicsTaskScheduler* scheduler)
: mHoldObject(holdObject)
#if BT_BULLET_VERSION < 310
, mHeights(makeHeights(heights, sqrtVerts))
#endif
, mTaskScheduler(scheduler)
{
#if BT_BULLET_VERSION < 310
mShape = std::make_unique<btHeightfieldTerrainShape>(
sqrtVerts, sqrtVerts,
getHeights(heights, mHeights),
1,
minH, maxH, 2,
PHY_FLOAT, false
);
#else
mShape = std::make_unique<btHeightfieldTerrainShape>(
sqrtVerts, sqrtVerts, heights, minH, maxH, 2, false);
#endif
mShape->setUseDiamondSubdivision(true);
mShape->setLocalScaling(btVector3(triSize, triSize, 1));
#if BT_BULLET_VERSION >= 289
// Accelerates some collision tests.
//
// Note: The accelerator data structure in Bullet is only used
// in some operations. This could be improved, see:
// https://github.com/bulletphysics/bullet3/issues/3276
mShape->buildAccelerator();
#endif
btTransform transform(btQuaternion::getIdentity(),
btVector3((x+0.5f) * triSize * (sqrtVerts-1),
(y+0.5f) * triSize * (sqrtVerts-1),
(maxH+minH)*0.5f));
mCollisionObject = std::make_unique<btCollisionObject>();
mCollisionObject->setCollisionShape(mShape.get());
mCollisionObject->setWorldTransform(transform);
mTaskScheduler->addCollisionObject(mCollisionObject.get(), CollisionType_HeightMap, CollisionType_Actor|CollisionType_Projectile);
}
HeightField::~HeightField()
{
mTaskScheduler->removeCollisionObject(mCollisionObject.get());
}
btCollisionObject* HeightField::getCollisionObject()
{
return mCollisionObject.get();
}
const btCollisionObject* HeightField::getCollisionObject() const
{
return mCollisionObject.get();
}
const btHeightfieldTerrainShape* HeightField::getShape() const
{
return mShape.get();
}
}