Files
FGL-Engine/src/engine/tree/octtree/OctTreeNode.cpp
2024-03-12 22:10:02 -04:00

394 lines
11 KiB
C++

//
// Created by kj16609 on 3/1/24.
//
#include "OctTreeNode.hpp"
#define GLM_ENABLE_EXPERIMENTAL
#include <glm/gtx/string_cast.hpp>
#include "engine/debug/drawers.hpp"
#include "engine/model/Model.hpp"
#include "engine/primitives/Frustum.hpp"
namespace fgl::engine
{
static bool draw_leaf_fit_bounds { false };
static bool draw_leaf_real_bounds { false };
static bool draw_inview_bounds { false };
void imGuiOctTreeSettings()
{
#if ENABLE_IMGUI
if ( ImGui::CollapsingHeader( "OctTree debug settings" ) )
{
ImGui::Checkbox( "Draw leaf fitted bounding boxes", &draw_leaf_fit_bounds );
ImGui::Checkbox( "Draw leaf real bounding boxes", &draw_leaf_real_bounds );
ImGui::Checkbox( "Draw ALL in view bounding boxes", &draw_inview_bounds );
}
#endif
}
void OctTreeNode::
getAllLeafsInFrustum( const Frustum< CoordinateSpace::World >& frustum, std::vector< NodeLeaf* >& out_leafs )
{
//Check if we are inside of the frustum.
if ( !isInFrustum( frustum ) ) return;
auto& leafs { out_leafs };
switch ( m_node_data.index() )
{
case 0: // NodeArray
{
assert( std::holds_alternative< NodeArray >( m_node_data ) );
NodeArray& node_array { std::get< NodeArray >( m_node_data ) };
//Search deeper
node_array[ LEFT ][ FORWARD ][ TOP ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ LEFT ][ FORWARD ][ BOTTOM ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ LEFT ][ BACK ][ TOP ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ LEFT ][ BACK ][ BOTTOM ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ RIGHT ][ FORWARD ][ TOP ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ RIGHT ][ FORWARD ][ BOTTOM ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ RIGHT ][ BACK ][ TOP ]->getAllLeafsInFrustum( frustum, out_leafs );
node_array[ RIGHT ][ BACK ][ BOTTOM ]->getAllLeafsInFrustum( frustum, out_leafs );
return;
}
case 1: // NodeLeaf
{
assert( std::holds_alternative< NodeLeaf >( m_node_data ) );
NodeLeaf& leaf { std::get< NodeLeaf >( m_node_data ) };
leafs.reserve( LEAF_RESERVE_SIZE );
leafs.emplace_back( &leaf );
//debug::world::drawBoundingBox( m_bounds );
return;
}
default:
std::unreachable();
}
std::unreachable();
}
OctTreeNode::OctTreeNode( const WorldCoordinate center, float span, OctTreeNode* parent ) :
m_fit_bounding_box( center, glm::vec3( span, span, span ) ),
m_bounds( center, span ),
m_node_data( NodeLeaf() ),
m_parent( parent )
{
assert( std::holds_alternative< NodeLeaf >( m_node_data ) );
std::get< NodeLeaf >( m_node_data ).reserve( MAX_NODES_IN_LEAF );
}
void OctTreeNode::split( int depth )
{
ZoneScoped;
if ( std::holds_alternative< NodeArray >( m_node_data ) ) return;
auto& game_objects { std::get< NodeLeaf >( m_node_data ) };
//Figure out the half span
const float half_span { m_bounds.span() / 2.0f };
const Coordinate< CoordinateSpace::World > center { m_bounds.getPosition() };
NodeArray new_nodes {};
const float left_x { center.x - half_span };
const float right_x { center.x + half_span };
const float forward_y { center.y - half_span };
const float backward_y { center.y + half_span };
const float top_z { center.z - half_span };
const float bottom_z { center.z + half_span };
new_nodes[ LEFT ][ FORWARD ][ TOP ] =
std::make_unique< OctTreeNode >( WorldCoordinate( left_x, forward_y, top_z ), half_span, this );
new_nodes[ LEFT ][ FORWARD ][ BOTTOM ] =
std::make_unique< OctTreeNode >( WorldCoordinate( left_x, forward_y, bottom_z ), half_span, this );
new_nodes[ LEFT ][ BACK ][ TOP ] =
std::make_unique< OctTreeNode >( WorldCoordinate( left_x, backward_y, top_z ), half_span, this );
new_nodes[ LEFT ][ BACK ][ BOTTOM ] =
std::make_unique< OctTreeNode >( WorldCoordinate( left_x, backward_y, bottom_z ), half_span, this );
new_nodes[ RIGHT ][ FORWARD ][ TOP ] =
std::make_unique< OctTreeNode >( WorldCoordinate( right_x, forward_y, top_z ), half_span, this );
new_nodes[ RIGHT ][ FORWARD ][ BOTTOM ] =
std::make_unique< OctTreeNode >( WorldCoordinate( right_x, forward_y, bottom_z ), half_span, this );
new_nodes[ RIGHT ][ BACK ][ TOP ] =
std::make_unique< OctTreeNode >( WorldCoordinate( right_x, backward_y, top_z ), half_span, this );
new_nodes[ RIGHT ][ BACK ][ BOTTOM ] =
std::make_unique< OctTreeNode >( WorldCoordinate( right_x, backward_y, bottom_z ), half_span, this );
[[assume( game_objects.size() <= MAX_NODES_IN_LEAF )]];
for ( GameObject& obj : game_objects )
{
const auto& obj_coordinate { obj.m_transform.translation };
const bool is_right { obj_coordinate.x > center.x };
const bool is_forward { obj_coordinate.y > center.y };
const bool is_up { obj_coordinate.z > center.z };
std::unique_ptr< OctTreeNode >& node { new_nodes[ is_right ][ is_forward ][ is_up ] };
assert( std::holds_alternative< NodeLeaf >( node->m_node_data ) );
std::get< NodeLeaf >( node->m_node_data ).emplace_back( std::move( obj ) );
}
this->m_node_data = std::move( new_nodes );
if ( depth - 1 >= 1 )
{
split( depth );
}
}
OctTreeNode* OctTreeNode::addGameObject( GameObject&& obj )
{
if ( std::holds_alternative< NodeLeaf >( m_node_data ) )
{
auto& objects { std::get< NodeLeaf >( m_node_data ) };
assert( objects.capacity() == MAX_NODES_IN_LEAF );
if ( objects.size() + 1 >= MAX_NODES_IN_LEAF )
{
split();
return this->addGameObject( std::move( obj ) );
}
else
{
objects.emplace_back( std::move( obj ) );
return this;
}
}
else
{
const auto& center { m_bounds.getPosition() };
const auto& obj_coordinate { obj.m_transform.translation };
const bool is_right { obj_coordinate.x > center.x };
const bool is_forward { obj_coordinate.y > center.y };
const bool is_up { obj_coordinate.z > center.z };
auto& nodes { std::get< NodeArray >( m_node_data ) };
return nodes[ is_right ][ is_forward ][ is_up ]->addGameObject( std::move( obj ) );
}
}
bool OctTreeNode::isInFrustum( const Frustum< CoordinateSpace::World >& frustum ) const
{
#if ENABLE_IMGUI
if ( isEmpty() ) return false;
if ( frustum.intersects( m_fit_bounding_box ) )
{
if ( draw_inview_bounds || std::holds_alternative< NodeLeaf >( this->m_node_data ) )
{
if ( draw_leaf_fit_bounds ) debug::world::drawBoundingBox( m_fit_bounding_box );
if ( draw_leaf_real_bounds ) debug::world::drawBoundingBox( m_bounds );
}
return true;
}
else
return false;
#else
return !isEmpty() && frustum.intersects( m_fit_bounding_box );
#endif
}
OctTreeNode* OctTreeNode::findID( const GameObject::ID id )
{
ZoneScoped;
if ( std::holds_alternative< NodeLeaf >( this->m_node_data ) )
{
//We are the last node. Check if we have the ID
const auto& game_objects { std::get< NodeLeaf >( m_node_data ) };
if ( std::find_if(
game_objects.begin(),
game_objects.end(),
[ id ]( const GameObject& obj ) { return obj.m_id == id; } )
!= game_objects.end() )
{
return this;
}
else
{
return nullptr;
}
}
else if ( std::holds_alternative< NodeArray >( this->m_node_data ) )
{
const auto& node_array { std::get< NodeArray >( this->m_node_data ) };
for ( std::size_t x = 0; x < 2; ++x )
{
for ( std::size_t y = 0; y < 2; ++y )
{
for ( std::size_t z = 0; z < 2; ++z )
{
const auto& node { node_array[ x ][ y ][ z ]->findID( id ) };
if ( node != nullptr ) return node;
}
}
}
return nullptr;
}
std::unreachable();
}
auto OctTreeNode::getGameObjectItter( const GameObject::ID id )
{
assert( std::holds_alternative< NodeLeaf >( this->m_node_data ) );
auto& game_objects { std::get< NodeLeaf >( this->m_node_data ) };
return std::find_if(
game_objects.begin(), game_objects.end(), [ id ]( const GameObject& obj ) { return id == obj.getId(); } );
}
bool OctTreeNode::canContain( const GameObject& obj )
{
return m_bounds.contains( obj.m_transform.translation );
}
GameObject OctTreeNode::extract( const GameObject::ID id )
{
auto itter { getGameObjectItter( id ) };
auto game_object { std::move( *itter ) };
auto& game_objects { std::get< NodeLeaf >( this->m_node_data ) };
game_objects.erase( itter );
return game_object;
}
OctTreeNode* OctTreeNode::getRoot()
{
if ( m_parent == nullptr )
return this;
else
return m_parent->getRoot();
}
void OctTreeNode::getAllLeafs( std::vector< NodeLeaf* >& objects )
{
ZoneScoped;
if ( std::holds_alternative< NodeLeaf >( m_node_data ) )
{
auto& leaf { std::get< NodeLeaf >( m_node_data ) };
//No point in us giving back an empy leaf
if ( leaf.size() > 0 ) objects.emplace_back( &leaf );
}
else
{
auto& nodes { std::get< NodeArray >( m_node_data ) };
for ( std::size_t x = 0; x < 2; ++x )
{
for ( std::size_t y = 0; y < 2; ++y )
{
for ( std::size_t z = 0; z < 2; ++z )
{
auto ret { nodes[ x ][ y ][ z ]->getAllLeafs() };
objects.insert( objects.end(), ret.begin(), ret.end() );
}
}
}
}
}
bool OctTreeNode::recalculateBoundingBoxes()
{
ZoneScoped;
const auto old_bounds { m_fit_bounding_box };
if ( std::holds_alternative< NodeArray >( m_node_data ) )
{
ZoneScopedN( "Process Array" );
bool bounding_box_changed { false };
auto& nodes { std::get< NodeArray >( m_node_data ) };
for ( std::size_t x = 0; x < 2; ++x )
{
for ( std::size_t y = 0; y < 2; ++y )
{
for ( std::size_t z = 0; z < 2; ++z )
{
auto& node { nodes[ x ][ y ][ z ] };
bounding_box_changed |= node->recalculateBoundingBoxes();
}
}
}
if ( bounding_box_changed )
{
//We need to update our bounding box now.
auto new_bounds { nodes[ 0 ][ 0 ][ 0 ]->m_fit_bounding_box };
for ( std::size_t x = 0; x < 2; ++x )
{
for ( std::size_t y = 0; y < 2; ++y )
{
for ( std::size_t z = 0; z < 2; ++z )
{
auto& node { nodes[ x ][ y ][ z ] };
new_bounds.combine( node->m_fit_bounding_box );
}
}
}
if ( new_bounds == old_bounds )
{
return false;
}
else
{
this->m_fit_bounding_box = new_bounds;
return true;
}
}
return false;
}
else if ( std::holds_alternative< NodeLeaf >( m_node_data ) )
{
ZoneScopedN( "Process Leaf" );
auto& game_objects { std::get< NodeLeaf >( m_node_data ) };
if ( game_objects.size() == 0 ) return false;
AxisAlignedBoundingBox< CoordinateSpace::World > new_bounds { game_objects[ 0 ].getBoundingBox() };
[[assume( game_objects.size() <= MAX_NODES_IN_LEAF )]];
for ( const GameObject& obj : game_objects )
{
new_bounds.combine( obj.getBoundingBox() );
}
if ( new_bounds == old_bounds )
{
return false;
}
else
{
this->m_fit_bounding_box = new_bounds;
return true;
}
}
std::unreachable();
}
} // namespace fgl::engine