Clump.cpp

// https://github.com/rwengine/openrw/blob/master/rwcore/data/Clump.cpp
#include "Clump.hpp"

#include <algorithm>
#include <limits>
#include <queue>

#include <glm/gtc/matrix_transform.hpp>

ModelFrame::ModelFrame(unsigned int index, glm::mat3 dR, glm::vec3 dT)
    : index(index)
    , defaultRotation(dR)
    , defaultTranslation(dT)
    , parent_(nullptr) {
    reset();
}

void ModelFrame::reset() {
    matrix = glm::translate(glm::mat4(1.0f), defaultTranslation) *
             glm::mat4(defaultRotation);
    updateHierarchyTransform();
}

void ModelFrame::updateHierarchyTransform() {
    // Update our own transformation
    if (parent_) {
        worldtransform_ = parent_->getWorldTransform() * matrix;
    } else {
        worldtransform_ = matrix;
    }
    for (const auto& child : children_) {
        child->updateHierarchyTransform();
    }
}

void ModelFrame::addChild(const ModelFramePtr& child) {
    // Make sure the child is an orphan
    if (child->getParent()) {
        auto& other_children = child->getParent()->children_;
        other_children.erase(
            std::remove(other_children.begin(), other_children.end(), child),
            other_children.end());
    }
    child->parent_ = this;
    children_.push_back(child);
    child->updateHierarchyTransform();
}

ModelFrame* ModelFrame::findDescendant(const std::string& name) const {
    for (const auto& frame : children_) {
        if (frame->getName() == name) {
            return frame.get();
        }

        auto result = frame->findDescendant(name);
        if (result) {
            return result;
        }
    }

    return nullptr;
}

ModelFramePtr ModelFrame::cloneHierarchy() const {
    auto self = std::make_shared<ModelFrame>(getIndex(), getDefaultRotation(),
                                             getDefaultTranslation());
    self->setName(getName());
    for (const auto& child : getChildren()) {
        auto childclone = child->cloneHierarchy();
        self->addChild(childclone);
    }

    return self;
}

AtomicPtr Atomic::clone(const ModelFramePtr& newFrame) const {
    auto newatomic = std::make_shared<Atomic>();
    newatomic->setGeometry(getGeometry());
    newatomic->setFrame(newFrame ? newFrame : getFrame());
    newatomic->setFlags(getFlags());
    return newatomic;
}

ModelFrame* Clump::findFrame(const std::string& name) const {
    if (rootframe_->getName() == name) {
        return rootframe_.get();
    }

    return rootframe_->findDescendant(name);
}

Clump::~Clump() = default;

void Clump::recalculateMetrics() {
    boundingRadius = std::numeric_limits<float>::min();
    for (const auto& atomic : atomics_) {
        const auto& geometry = atomic->getGeometry();
        if (!geometry) {
            continue;
        }
        const auto& bounds = geometry->geometryBounds;
        boundingRadius = std::max(boundingRadius,
                                  glm::length(bounds.center) + bounds.radius);
    }
}

ClumpPtr Clump::clone() const {
    // Clone frame hierarchy
    auto newroot = rootframe_->cloneHierarchy();
    auto clump = std::make_shared<Clump>();
    clump->setFrame(newroot);
    clump->boundingRadius = boundingRadius;

    // This isn't the most optimal implementation, but this code is likely
    // to be replaced soon.
    auto find_new_frame = [&](const ModelFramePtr& old) -> ModelFramePtr {
        std::queue<ModelFramePtr> open;
        open.push(newroot);
        while (!open.empty()) {
            auto frame = open.front();
            open.pop();
            if (frame->getIndex() == old->getIndex()) {
                return frame;
            }
            for (const auto& child : frame->getChildren()) {
                open.push(child);
            }
        }
        return nullptr;
    };

    // Generate new atomics
    for (const auto& atomic : getAtomics()) {
        auto newatomic = atomic->clone();
        // Replace the original frame with the cloned frame
        if (atomic->getFrame()) {
            newatomic->setFrame(find_new_frame(atomic->getFrame()));
        }
        clump->addAtomic(newatomic);
    }

    return clump;
}

#ifdef __EMSCRIPTEN__
#include <emscripten/bind.h>
using namespace emscripten;
EMSCRIPTEN_BINDINGS(Clump) {
    class_<Clump>("Clump")
        .smart_ptr_constructor("Clump", &std::make_shared<Clump>)
        ;
}
#endif