// viewer_lookat.hxx -- class for managing a "look at" viewer in // the flightgear world. // // Written by Curtis Olson, started October 2000. // // Copyright (C) 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. // // $Id$ #include #ifdef HAVE_CONFIG_H # include #endif #include // plib include #include #include #include #include #include #include #include "globals.hxx" #include "viewer_lookat.hxx" // Constructor FGViewerLookAt::FGViewerLookAt( void ) { } static void fgLookAt( sgVec3 eye, sgVec3 center, sgVec3 up, sgMat4 &m ) { double x[3], y[3], z[3]; double mag; /* Make rotation matrix */ /* Z vector */ z[0] = eye[0] - center[0]; z[1] = eye[1] - center[1]; z[2] = eye[2] - center[2]; mag = sqrt( z[0]*z[0] + z[1]*z[1] + z[2]*z[2] ); if (mag) { /* mpichler, 19950515 */ z[0] /= mag; z[1] /= mag; z[2] /= mag; } /* Y vector */ y[0] = up[0]; y[1] = up[1]; y[2] = up[2]; /* X vector = Y cross Z */ x[0] = y[1]*z[2] - y[2]*z[1]; x[1] = -y[0]*z[2] + y[2]*z[0]; x[2] = y[0]*z[1] - y[1]*z[0]; /* Recompute Y = Z cross X */ y[0] = z[1]*x[2] - z[2]*x[1]; y[1] = -z[0]*x[2] + z[2]*x[0]; y[2] = z[0]*x[1] - z[1]*x[0]; /* mpichler, 19950515 */ /* cross product gives area of parallelogram, which is < 1.0 for * non-perpendicular unit-length vectors; so normalize x, y here */ mag = sqrt( x[0]*x[0] + x[1]*x[1] + x[2]*x[2] ); if (mag) { x[0] /= mag; x[1] /= mag; x[2] /= mag; } mag = sqrt( y[0]*y[0] + y[1]*y[1] + y[2]*y[2] ); if (mag) { y[0] /= mag; y[1] /= mag; y[2] /= mag; } #define M(row,col) m[row][col] M(0,0) = x[0]; M(0,1) = x[1]; M(0,2) = x[2]; M(0,3) = 0.0; M(1,0) = y[0]; M(1,1) = y[1]; M(1,2) = y[2]; M(1,3) = 0.0; M(2,0) = z[0]; M(2,1) = z[1]; M(2,2) = z[2]; M(2,3) = 0.0; M(3,0) = -eye[0]; M(3,1) = -eye[1]; M(3,2) = -eye[2]; M(3,3) = 1.0; #undef M } // convert sgMat4 to MAT3 and print static void print_sgMat4( sgMat4 &in) { int i, j; for ( i = 0; i < 4; i++ ) { for ( j = 0; j < 4; j++ ) { printf("%10.4f ", in[i][j]); } cout << endl; } } // Update the view parameters void FGViewerLookAt::update() { Point3D tmp; sgVec3 minus_z, forward; sgMat4 VIEWo; // calculate the cartesion coords of the current lat/lon/0 elev Point3D p = Point3D( geod_view_pos[0], geod_view_pos[1], sea_level_radius ); tmp = sgPolarToCart3d(p) - scenery.center; sgSetVec3( zero_elev, tmp[0], tmp[1], tmp[2] ); // calculate view position in current FG view coordinate system // p.lon & p.lat are already defined earlier, p.radius was set to // the sea level radius, so now we add in our altitude. if ( geod_view_pos[2] > (scenery.cur_elev + 0.5 * METER_TO_FEET) ) { p.setz( p.radius() + geod_view_pos[2] ); } else { p.setz( p.radius() + scenery.cur_elev + 0.5 * METER_TO_FEET ); } tmp = sgPolarToCart3d(p); sgdSetVec3( abs_view_pos, tmp[0], tmp[1], tmp[2] ); // view_pos = abs_view_pos - scenery.center; sgdVec3 sc; sgdSetVec3( sc, scenery.center.x(), scenery.center.y(), scenery.center.z()); sgdVec3 vp; sgdSubVec3( vp, abs_view_pos, sc ); sgSetVec3( view_pos, vp ); FG_LOG( FG_VIEW, FG_DEBUG, "sea level radius = " << sea_level_radius ); FG_LOG( FG_VIEW, FG_DEBUG, "Polar view pos = " << p ); FG_LOG( FG_VIEW, FG_DEBUG, "Absolute view pos = " << abs_view_pos[0] << "," << abs_view_pos[1] << "," << abs_view_pos[2] ); FG_LOG( FG_VIEW, FG_DEBUG, "Relative view pos = " << view_pos[0] << "," << view_pos[1] << "," << view_pos[2] ); FG_LOG( FG_VIEW, FG_DEBUG, "view forward = " << view_forward[0] << "," << view_forward[1] << "," << view_forward[2] ); FG_LOG( FG_VIEW, FG_DEBUG, "view up = " << view_up[0] << "," << view_up[1] << "," << view_up[2] ); // Make the VIEW matrix. fgLookAt( view_pos, view_forward, view_up, VIEW ); // cout << "VIEW matrix" << endl; // print_sgMat4( VIEW ); // the VIEW matrix includes both rotation and translation. Let's // knock out the translation part to make the VIEW_ROT matrix sgCopyMat4( VIEW_ROT, VIEW ); VIEW_ROT[3][0] = VIEW_ROT[3][1] = VIEW_ROT[3][2] = 0.0; // Make the world up rotation matrix sgMakeRotMat4( UP, geod_view_pos[0] * RAD_TO_DEG, 0.0, -geod_view_pos[1] * RAD_TO_DEG ); // use a clever observation into the nature of our tranformation // matrix to grab the world_up vector sgSetVec3( world_up, UP[0][0], UP[0][1], UP[0][2] ); // cout << "World Up = " << world_up[0] << "," << world_up[1] << "," // << world_up[2] << endl; //!!!!!!!!!!!!!!!!!!! // THIS IS THE EXPERIMENTAL VIEWING ANGLE SHIFTER // THE MAJORITY OF THE WORK IS DONE IN GUI.CXX // this in gui.cxx for now just testing extern float quat_mat[4][4]; sgPreMultMat4( VIEW, quat_mat); // !!!!!!!!!! testing // Given a vector pointing straight down (-Z), map into onto the // local plane representing "horizontal". This should give us the // local direction for moving "south". sgSetVec3( minus_z, 0.0, 0.0, -1.0 ); sgmap_vec_onto_cur_surface_plane(world_up, view_pos, minus_z, surface_south); sgNormalizeVec3(surface_south); // cout << "Surface direction directly south " << surface_south[0] << "," // << surface_south[1] << "," << surface_south[2] << endl; // now calculate the surface east vector #define USE_FAST_SURFACE_EAST #ifdef USE_FAST_SURFACE_EAST sgVec3 world_down; sgNegateVec3(world_down, world_up); sgVectorProductVec3(surface_east, surface_south, world_down); #else sgMakeRotMat4( TMP, FG_PI_2 * RAD_TO_DEG, world_up ); // cout << "sgMat4 TMP" << endl; // print_sgMat4( TMP ); sgXformVec3(surface_east, surface_south, TMP); #endif // USE_FAST_SURFACE_EAST // cout << "Surface direction directly east " << surface_east[0] << "," // << surface_east[1] << "," << surface_east[2] << endl; // cout << "Should be close to zero = " // << sgScalarProductVec3(surface_south, surface_east) << endl; set_clean(); } // Destructor FGViewerLookAt::~FGViewerLookAt( void ) { }