// viewer.hxx -- class for managing a viewer in the flightgear world. // // Written by Curtis Olson, started August 1997. // overhaul started October 2000. // // Copyright (C) 1997 - 2000 Curtis L. Olson - curt@flightgear.org // // 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., 675 Mass Ave, Cambridge, MA 02139, USA. // // $Id$ #ifndef _VIEWER_HXX #define _VIEWER_HXX #ifndef __cplusplus # error This library requires C++ #endif #include #include // plib include #include "fgfs.hxx" #define FG_FOV_MIN 0.1 #define FG_FOV_MAX 179.9 // Define a structure containing view information class FGViewer { public: enum fgViewType { FG_RPH = 0, FG_LOOKAT = 1, FG_HPR = 2 }; enum fgScalingType { // nominal Field Of View actually applies to ... FG_SCALING_WIDTH, // window width FG_SCALING_MAX, // max(width, height) // FG_SCALING_G_MEAN, // geometric_mean(width, height) // FG_SCALING_INDEPENDENT // whole screen }; private: // flag forcing a recalc of derived view parameters bool dirty; protected: fgViewType _type; fgScalingType scalingType; // the nominal field of view (angle, in degrees) double fov; // ratio of window width and height; height = width * aspect_ratio double aspect_ratio; // the current view offset angle from forward (rotated about the // view_up vector) double view_offset; bool reverse_view_offset; // the goal view offset angle (used for smooth view changes) double goal_view_offset; // the view tilt angles double view_tilt; double goal_view_tilt; // geodetic view position sgdVec3 geod_view_pos; // absolute view position in earth coordinates sgdVec3 abs_view_pos; // view position in opengl world coordinates (this is the // abs_view_pos translated to scenery.center) sgVec3 view_pos; // radius to sea level from center of the earth (m) double sea_level_radius; // cartesion coordinates of current lon/lat if at sea level // translated to scenery.center sgVec3 zero_elev; // height ASL of the terrain for our current view position // (future?) double ground_elev; // pilot offset from center of gravity. The X axis is positive // out the tail, Y is out the right wing, and Z is positive up. // Distances in meters of course. sgVec3 pilot_offset; // surface vector heading south sgVec3 surface_south; // surface vector heading east (used to unambiguously align sky // with sun) sgVec3 surface_east; // world up vector (normal to the plane tangent to the earth's // surface at the spot we are directly above sgVec3 world_up; // sg versions of our friendly matrices sgMat4 VIEW, VIEW_ROT, UP; inline void set_dirty() { dirty = true; } inline void set_clean() { dirty = false; } // Update the view volume, position, and orientation virtual void update() = 0; public: // Constructor FGViewer( void ); // Destructor virtual ~FGViewer( void ); virtual void init (); virtual void bind (); virtual void unbind (); virtual void update (int dt); ////////////////////////////////////////////////////////////////////// // setter functions ////////////////////////////////////////////////////////////////////// inline void set_fov( double fov_deg ) { fov = fov_deg; } inline void set_aspect_ratio( double r ) { aspect_ratio = r; } inline void set_view_offset( double a ) { set_dirty(); view_offset = a; } inline void inc_view_offset( double amt ) { set_dirty(); view_offset += amt; } inline void set_goal_view_offset( double a) { set_dirty(); goal_view_offset = a; while ( goal_view_offset < 0 ) { goal_view_offset += 360.0; } while ( goal_view_offset > 360.0 ) { goal_view_offset -= 360.0; } } inline void set_reverse_view_offset( bool val ) { reverse_view_offset = val; } inline void set_view_tilt( double a ) { set_dirty(); view_tilt = a; } inline void inc_view_tilt( double amt ) { set_dirty(); view_tilt += amt; } inline void set_goal_view_tilt( double a) { set_dirty(); goal_view_tilt = a; while ( goal_view_tilt < 0 ) { goal_view_tilt += 360.0; } while ( goal_view_tilt > 360.0 ) { goal_view_tilt -= 360.0; } } inline void set_geod_view_pos( double lon, double lat, double alt ) { // data should be in radians and meters asl set_dirty(); // cout << "set_geod_view_pos = " << lon << ", " << lat << ", " << alt // << endl; sgdSetVec3( geod_view_pos, lon, lat, alt ); } inline void set_pilot_offset( float x, float y, float z ) { set_dirty(); sgSetVec3( pilot_offset, x, y, z ); } inline void set_sea_level_radius( double r ) { // data should be in meters from the center of the earth set_dirty(); sea_level_radius = r; } ////////////////////////////////////////////////////////////////////// // accessor functions ////////////////////////////////////////////////////////////////////// inline int get_type() const { return _type ; } inline int is_a( int t ) const { return get_type() == t ; } inline bool is_dirty() const { return dirty; } inline double get_fov() const { return fov; } inline double get_aspect_ratio() const { return aspect_ratio; } inline double get_view_offset() const { return view_offset; } inline bool get_reverse_view_offset() const { return reverse_view_offset; } inline double get_goal_view_offset() const { return goal_view_offset; } inline double get_view_tilt() const { return view_tilt; } inline double get_goal_view_tilt() const { return goal_view_tilt; } inline double *get_geod_view_pos() { return geod_view_pos; } inline float *get_pilot_offset() { return pilot_offset; } inline double get_sea_level_radius() const { return sea_level_radius; } // Get horizontal field of view angle, in degrees. double get_h_fov(); // Get vertical field of view angle, in degrees. double get_v_fov(); ////////////////////////////////////////////////////////////////////// // derived values accessor functions ////////////////////////////////////////////////////////////////////// inline double *get_abs_view_pos() { if ( dirty ) { update(); } return abs_view_pos; } inline float *get_view_pos() { if ( dirty ) { update(); } return view_pos; } inline float *get_zero_elev() { if ( dirty ) { update(); } return zero_elev; } // (future?) // inline double get_ground_elev() { // if ( dirty ) { update(); } // return ground_elev; // } inline float *get_surface_south() { if ( dirty ) { update(); } return surface_south; } inline float *get_surface_east() { if ( dirty ) { update(); } return surface_east; } inline float *get_world_up() { if ( dirty ) { update(); } return world_up; } inline const sgVec4 *get_VIEW() { if ( dirty ) { update(); } return VIEW; } inline const sgVec4 *get_VIEW_ROT() { if ( dirty ) { update(); } return VIEW_ROT; } inline const sgVec4 *get_UP() { if ( dirty ) { update(); } return UP; } }; #endif // _VIEWER_HXX