// scenery.cxx -- data structures and routines for managing scenery. // // Written by Curtis Olson, started May 1997. // // Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License as // published by the Free Software Foundation; either version 2 of the // License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, but // WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. // // $Id$ #ifdef HAVE_CONFIG_H # include #endif #include #include #include #include #include #include #include #include
#include "hitlist.hxx" #include "scenery.hxx" // Scenery Management system FGScenery::FGScenery() : center(0, 0, 0) { SG_LOG( SG_TERRAIN, SG_INFO, "Initializing scenery subsystem" ); } // Initialize the Scenery Management system FGScenery::~FGScenery() { } void FGScenery::init() { // Scene graph root scene_graph = new ssgRoot; scene_graph->setName( "Scene" ); // Terrain branch terrain_branch = new ssgBranch; terrain_branch->setName( "Terrain" ); scene_graph->addKid( terrain_branch ); models_branch = new ssgBranch; models_branch->setName( "Models" ); scene_graph->addKid( models_branch ); aircraft_branch = new ssgBranch; aircraft_branch->setName( "Aircraft" ); scene_graph->addKid( aircraft_branch ); // Lighting gnd_lights_root = new ssgRoot; gnd_lights_root->setName( "Ground Lighting Root" ); vasi_lights_root = new ssgRoot; vasi_lights_root->setName( "VASI/PAPI Lighting Root" ); rwy_lights_root = new ssgRoot; rwy_lights_root->setName( "Runway Lighting Root" ); taxi_lights_root = new ssgRoot; taxi_lights_root->setName( "Taxi Lighting Root" ); // Initials values needed by the draw-time object loader sgUserDataInit( globals->get_model_lib(), globals->get_fg_root(), globals->get_props(), globals->get_sim_time_sec() ); } void FGScenery::update(double dt) { } void FGScenery::bind() { } void FGScenery::unbind() { } void FGScenery::set_center( const SGVec3d& p ) { if (center == p) return; center = p; placement_list_type::iterator it = _placement_list.begin(); while (it != _placement_list.end()) { (*it)->setSceneryCenter(center.sg()); ++it; } } void FGScenery::register_placement_transform(ssgPlacementTransform *trans) { _placement_list.push_back(trans); trans->setSceneryCenter(center.sg()); } void FGScenery::unregister_placement_transform(ssgPlacementTransform *trans) { placement_list_type::iterator it = _placement_list.begin(); while (it != _placement_list.end()) { if ((*it) == trans) { it = _placement_list.erase(it); } else ++it; } } bool FGScenery::get_elevation_m(double lat, double lon, double max_alt, double& alt, const SGMaterial** material, bool exact) { SGGeod geod = SGGeod::fromDegM(lon, lat, max_alt); SGVec3d pos = SGVec3d::fromGeod(geod); return get_cart_elevation_m(pos, 0, alt, material, exact); } bool FGScenery::get_cart_elevation_m(const SGVec3d& pos, double max_altoff, double& alt, const SGMaterial** material, bool exact) { if ( norm1(pos) < 1 ) return false; SGVec3d saved_center = center; bool replaced_center = false; if (exact) { if (30*30 < distSqr(pos, center)) { set_center( pos ); replaced_center = true; } } // overridden with actual values if a terrain intersection is // found int this_hit; double hit_radius = 0.0; SGVec3d hit_normal(0, 0, 0); SGVec3d sc = center; SGVec3d ncpos = pos; FGHitList hit_list; // scenery center has been properly defined so any hit should // be valid (and not just luck) bool hit = fgCurrentElev(ncpos.sg(), max_altoff+length(pos), sc.sg(), get_scene_graph(), &hit_list, &alt, &hit_radius, hit_normal.sg(), this_hit); if (material) { *material = 0; if (hit) { ssgEntity *entity = hit_list.get_entity( this_hit ); if (entity && entity->isAKindOf(ssgTypeLeaf())) { ssgLeaf* leaf = static_cast(entity); *material = globals->get_matlib()->findMaterial(leaf); } } } if (replaced_center) set_center( saved_center ); return hit; } bool FGScenery::get_cart_ground_intersection(const SGVec3d& pos, const SGVec3d& dir, SGVec3d& nearestHit, bool exact) { // We assume that starting positions in the center of the earth are invalid if ( norm1(pos) < 1 ) return false; // Well that 'exactness' is somehow problematic, but makes at least sure // that we don't compute that with a cenery center at the other side of // the world ... SGVec3d saved_center = center; bool replaced_center = false; if (exact) { if (30*30 < distSqr(pos, center)) { set_center( pos ); replaced_center = true; } } // Not yet found any hit ... bool result = false; // Make really sure the direction is normalized, is really cheap compared to // computation of ground intersection. SGVec3d normalizedDir = normalize(dir); SGVec3d relativePos = pos - center; // At the moment only intersection with the terrain? FGHitList hit_list; hit_list.Intersect(globals->get_scenery()->get_terrain_branch(), relativePos.sg(), normalizedDir.sg()); double dist = DBL_MAX; int hitcount = hit_list.num_hits(); for (int i = 0; i < hitcount; ++i) { // Check for the nearest hit SGVec3d diff = SGVec3d(hit_list.get_point(i)) - relativePos; // We only want hits in front of us ... if (dot(normalizedDir, diff) < 0) continue; // find the nearest hit double nDist = dot(diff, diff); if (dist < nDist) continue; // Store the hit point dist = nDist; nearestHit = SGVec3d(hit_list.get_point(i)) + center; result = true; } if (replaced_center) set_center( saved_center ); return result; }