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openmw/components/nifbullet/bulletnifloader.cpp

433 lines
15 KiB
C++

#include "bulletnifloader.hpp"
#include <cassert>
#include <vector>
#include <variant>
#include <BulletCollision/CollisionShapes/btBoxShape.h>
#include <BulletCollision/CollisionShapes/btTriangleMesh.h>
#include <BulletCollision/CollisionShapes/btScaledBvhTriangleMeshShape.h>
#include <components/debug/debuglog.hpp>
#include <components/misc/convert.hpp>
#include <components/misc/stringops.hpp>
#include <components/nif/node.hpp>
#include <components/nif/data.hpp>
#include <components/nif/extra.hpp>
namespace
{
osg::Matrixf getWorldTransform(const Nif::Node& node)
{
if(node.parent != nullptr)
return node.trafo.toMatrix() * getWorldTransform(*node.parent);
return node.trafo.toMatrix();
}
bool pathFileNameStartsWithX(const std::string& path)
{
const std::size_t slashpos = path.find_last_of("/\\");
const std::size_t letterPos = slashpos == std::string::npos ? 0 : slashpos + 1;
return letterPos < path.size() && (path[letterPos] == 'x' || path[letterPos] == 'X');
}
void fillTriangleMesh(btTriangleMesh& mesh, const Nif::NiTriShapeData& data, const osg::Matrixf &transform)
{
const std::vector<osg::Vec3f> &vertices = data.vertices;
const std::vector<unsigned short> &triangles = data.triangles;
mesh.preallocateVertices(static_cast<int>(vertices.size()));
mesh.preallocateIndices(static_cast<int>(triangles.size()));
for (std::size_t i = 0; i < triangles.size(); i += 3)
{
mesh.addTriangle(
Misc::Convert::toBullet(vertices[triangles[i + 0]] * transform),
Misc::Convert::toBullet(vertices[triangles[i + 1]] * transform),
Misc::Convert::toBullet(vertices[triangles[i + 2]] * transform)
);
}
}
void fillTriangleMesh(btTriangleMesh& mesh, const Nif::NiTriStripsData& data, const osg::Matrixf &transform)
{
const std::vector<osg::Vec3f> &vertices = data.vertices;
const std::vector<std::vector<unsigned short>> &strips = data.strips;
mesh.preallocateVertices(static_cast<int>(vertices.size()));
int numTriangles = 0;
for (const std::vector<unsigned short>& strip : strips)
{
// Each strip with N points contains information about N-2 triangles.
if (strip.size() >= 3)
numTriangles += static_cast<int>(strip.size()-2);
}
mesh.preallocateIndices(static_cast<int>(numTriangles));
// It's triangulation time. Totally not a NifSkope spell ripoff.
for (const std::vector<unsigned short>& strip : strips)
{
// Can't make a triangle from less than 3 points.
if (strip.size() < 3)
continue;
unsigned short a = strip[0], b = strip[0], c = strip[1];
for (size_t i = 2; i < strip.size(); i++)
{
a = b;
b = c;
c = strip[i];
if (a != b && b != c && a != c)
{
if (i%2==0)
{
mesh.addTriangle(
Misc::Convert::toBullet(vertices[a] * transform),
Misc::Convert::toBullet(vertices[b] * transform),
Misc::Convert::toBullet(vertices[c] * transform)
);
}
else
{
mesh.addTriangle(
Misc::Convert::toBullet(vertices[a] * transform),
Misc::Convert::toBullet(vertices[c] * transform),
Misc::Convert::toBullet(vertices[b] * transform)
);
}
}
}
}
}
template <class Function>
auto handleNiGeometry(const Nif::NiGeometry& geometry, Function&& function)
-> decltype(function(static_cast<const Nif::NiTriShapeData&>(geometry.data.get())))
{
if (geometry.recType == Nif::RC_NiTriShape || geometry.recType == Nif::RC_BSLODTriShape)
{
if (geometry.data->recType != Nif::RC_NiTriShapeData)
return {};
auto data = static_cast<const Nif::NiTriShapeData*>(geometry.data.getPtr());
if (data->triangles.empty())
return {};
return function(static_cast<const Nif::NiTriShapeData&>(*data));
}
if (geometry.recType == Nif::RC_NiTriStrips)
{
if (geometry.data->recType != Nif::RC_NiTriStripsData)
return {};
auto data = static_cast<const Nif::NiTriStripsData*>(geometry.data.getPtr());
if (data->strips.empty())
return {};
return function(static_cast<const Nif::NiTriStripsData&>(*data));
}
return {};
}
std::monostate fillTriangleMesh(std::unique_ptr<btTriangleMesh>& mesh, const Nif::NiGeometry& geometry, const osg::Matrixf &transform)
{
return handleNiGeometry(geometry, [&] (const auto& data)
{
if (mesh == nullptr)
mesh.reset(new btTriangleMesh(false));
fillTriangleMesh(*mesh, data, transform);
return std::monostate {};
});
}
std::unique_ptr<btTriangleMesh> makeChildMesh(const Nif::NiGeometry& geometry)
{
return handleNiGeometry(geometry, [&] (const auto& data)
{
std::unique_ptr<btTriangleMesh> mesh(new btTriangleMesh);
fillTriangleMesh(*mesh, data, osg::Matrixf());
return mesh;
});
}
}
namespace NifBullet
{
osg::ref_ptr<Resource::BulletShape> BulletNifLoader::load(const Nif::File& nif)
{
mShape = new Resource::BulletShape;
mCompoundShape.reset();
mStaticMesh.reset();
mAvoidStaticMesh.reset();
const size_t numRoots = nif.numRoots();
std::vector<const Nif::Node*> roots;
for (size_t i = 0; i < numRoots; ++i)
{
const Nif::Record* r = nif.getRoot(i);
if (!r)
continue;
const Nif::Node* node = dynamic_cast<const Nif::Node*>(r);
if (node)
roots.emplace_back(node);
}
const std::string filename = nif.getFilename();
if (roots.empty())
{
warn("Found no root nodes in NIF file " + filename);
return mShape;
}
// Try to find a valid bounding box first. If one's found for any root node, use that.
for (const Nif::Node* node : roots)
{
if (findBoundingBox(*node, filename))
{
const btVector3 extents = Misc::Convert::toBullet(mShape->mCollisionBox.mExtents);
const btVector3 center = Misc::Convert::toBullet(mShape->mCollisionBox.mCenter);
std::unique_ptr<btCompoundShape> compound (new btCompoundShape);
std::unique_ptr<btBoxShape> boxShape(new btBoxShape(extents));
btTransform transform = btTransform::getIdentity();
transform.setOrigin(center);
compound->addChildShape(transform, boxShape.get());
boxShape.release();
mShape->mCollisionShape.reset(compound.release());
return mShape;
}
}
// files with the name convention xmodel.nif usually have keyframes stored in a separate file xmodel.kf (see Animation::addAnimSource).
// assume all nodes in the file will be animated
const bool isAnimated = pathFileNameStartsWithX(filename);
// If there's no bounding box, we'll have to generate a Bullet collision shape
// from the collision data present in every root node.
for (const Nif::Node* node : roots)
{
bool autogenerated = hasAutoGeneratedCollision(*node);
handleNode(filename, *node, 0, autogenerated, isAnimated, autogenerated);
}
if (mCompoundShape)
{
if (mStaticMesh != nullptr && mStaticMesh->getNumTriangles() > 0)
{
btTransform trans;
trans.setIdentity();
std::unique_ptr<btCollisionShape> child(new Resource::TriangleMeshShape(mStaticMesh.get(), true));
mCompoundShape->addChildShape(trans, child.get());
child.release();
mStaticMesh.release();
}
mShape->mCollisionShape = std::move(mCompoundShape);
}
else if (mStaticMesh != nullptr && mStaticMesh->getNumTriangles() > 0)
{
mShape->mCollisionShape.reset(new Resource::TriangleMeshShape(mStaticMesh.get(), true));
mStaticMesh.release();
}
if (mAvoidStaticMesh != nullptr && mAvoidStaticMesh->getNumTriangles() > 0)
{
mShape->mAvoidCollisionShape.reset(new Resource::TriangleMeshShape(mAvoidStaticMesh.get(), false));
mAvoidStaticMesh.release();
}
return mShape;
}
// Find a boundingBox in the node hierarchy.
// Return: use bounding box for collision?
bool BulletNifLoader::findBoundingBox(const Nif::Node& node, const std::string& filename)
{
if (node.hasBounds)
{
unsigned int type = node.bounds.type;
switch (type)
{
case Nif::NiBoundingVolume::Type::BOX_BV:
mShape->mCollisionBox.mExtents = node.bounds.box.extents;
mShape->mCollisionBox.mCenter = node.bounds.box.center;
break;
default:
{
std::stringstream warning;
warning << "Unsupported NiBoundingVolume type " << type << " in node " << node.recIndex;
warning << " in file " << filename;
warn(warning.str());
}
}
if (node.flags & Nif::NiNode::Flag_BBoxCollision)
{
return true;
}
}
if (const Nif::NiNode *ninode = dynamic_cast<const Nif::NiNode*>(&node))
{
const Nif::NodeList &list = ninode->children;
for(size_t i = 0;i < list.length();i++)
{
if(!list[i].empty())
{
if (findBoundingBox(list[i].get(), filename))
return true;
}
}
}
return false;
}
bool BulletNifLoader::hasAutoGeneratedCollision(const Nif::Node& rootNode)
{
if (const Nif::NiNode* ninode = dynamic_cast<const Nif::NiNode*>(&rootNode))
{
const Nif::NodeList &list = ninode->children;
for(size_t i = 0;i < list.length();i++)
{
if(!list[i].empty())
{
if(list[i].getPtr()->recType == Nif::RC_RootCollisionNode)
return false;
}
}
}
return true;
}
void BulletNifLoader::handleNode(const std::string& fileName, const Nif::Node& node, int flags,
bool isCollisionNode, bool isAnimated, bool autogenerated, bool avoid)
{
// TODO: allow on-the fly collision switching via toggling this flag
if (node.recType == Nif::RC_NiCollisionSwitch && !(node.flags & Nif::NiNode::Flag_ActiveCollision))
return;
// Accumulate the flags from all the child nodes. This works for all
// the flags we currently use, at least.
flags |= node.flags;
if (!node.controller.empty() && node.controller->recType == Nif::RC_NiKeyframeController
&& (node.controller->flags & Nif::NiNode::ControllerFlag_Active))
isAnimated = true;
isCollisionNode = isCollisionNode || (node.recType == Nif::RC_RootCollisionNode);
// Don't collide with AvoidNode shapes
avoid = avoid || (node.recType == Nif::RC_AvoidNode);
// We encountered a RootCollisionNode inside autogenerated mesh. It is not right.
if (node.recType == Nif::RC_RootCollisionNode && autogenerated)
Log(Debug::Info) << "RootCollisionNode is not attached to the root node in " << fileName << ". Treating it as a common NiTriShape.";
// Check for extra data
for (Nif::ExtraPtr e = node.extra; !e.empty(); e = e->next)
{
if (e->recType == Nif::RC_NiStringExtraData)
{
// String markers may contain important information
// affecting the entire subtree of this node
Nif::NiStringExtraData *sd = (Nif::NiStringExtraData*)e.getPtr();
if (Misc::StringUtils::ciCompareLen(sd->string, "NC", 2) == 0)
{
// No collision. Use an internal flag setting to mark this.
flags |= 0x800;
}
else if (sd->string == "MRK" && autogenerated)
{
// Marker can still have collision if the model explicitely specifies it via a RootCollisionNode.
return;
}
}
}
if (isCollisionNode)
{
// NOTE: a trishape with hasBounds=true, but no BBoxCollision flag should NOT go through handleNiTriShape!
// It must be ignored completely.
// (occurs in tr_ex_imp_wall_arch_04.nif)
if(!node.hasBounds && (node.recType == Nif::RC_NiTriShape
|| node.recType == Nif::RC_NiTriStrips
|| node.recType == Nif::RC_BSLODTriShape))
{
handleNiTriShape(node, flags, getWorldTransform(node), isAnimated, avoid);
}
}
// For NiNodes, loop through children
if (const Nif::NiNode *ninode = dynamic_cast<const Nif::NiNode*>(&node))
{
const Nif::NodeList &list = ninode->children;
for(size_t i = 0;i < list.length();i++)
{
if (list[i].empty())
continue;
assert(list[i].get().parent == &node);
handleNode(fileName, list[i].get(), flags, isCollisionNode, isAnimated, autogenerated, avoid);
}
}
}
void BulletNifLoader::handleNiTriShape(const Nif::Node& nifNode, int flags, const osg::Matrixf &transform,
bool isAnimated, bool avoid)
{
// If the object was marked "NCO" earlier, it shouldn't collide with
// anything. So don't do anything.
if ((flags & 0x800))
return;
handleNiTriShape(static_cast<const Nif::NiGeometry&>(nifNode), transform, isAnimated, avoid);
}
void BulletNifLoader::handleNiTriShape(const Nif::NiGeometry& niGeometry, const osg::Matrixf &transform,
bool isAnimated, bool avoid)
{
if (niGeometry.data.empty() || niGeometry.data->vertices.empty())
return;
if (!niGeometry.skin.empty())
isAnimated = false;
if (isAnimated)
{
std::unique_ptr<btTriangleMesh> childMesh = makeChildMesh(niGeometry);
if (childMesh == nullptr || childMesh->getNumTriangles() == 0)
return;
if (!mCompoundShape)
mCompoundShape.reset(new btCompoundShape);
std::unique_ptr<Resource::TriangleMeshShape> childShape(new Resource::TriangleMeshShape(childMesh.get(), true));
childMesh.release();
float scale = niGeometry.trafo.scale;
for (const Nif::Node* parent = niGeometry.parent; parent != nullptr; parent = parent->parent)
scale *= parent->trafo.scale;
osg::Quat q = transform.getRotate();
osg::Vec3f v = transform.getTrans();
childShape->setLocalScaling(btVector3(scale, scale, scale));
btTransform trans(btQuaternion(q.x(), q.y(), q.z(), q.w()), btVector3(v.x(), v.y(), v.z()));
mShape->mAnimatedShapes.emplace(niGeometry.recIndex, mCompoundShape->getNumChildShapes());
mCompoundShape->addChildShape(trans, childShape.get());
childShape.release();
}
else if (avoid)
fillTriangleMesh(mAvoidStaticMesh, niGeometry, transform);
else
fillTriangleMesh(mStaticMesh, niGeometry, transform);
}
} // namespace NifBullet