// viewer.cxx -- class for managing a viewer in the flightgear world.
//
// Written by Curtis Olson, started August 1997.
// overhaul started October 2000.
// partially rewritten by Jim Wilson jim@kelcomaine.com using interface
// by David Megginson March 2002
//
// 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.
//
// $Id$
#include <simgear/compiler.h>
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <simgear/debug/logstream.hxx>
#include <simgear/constants.h>
#include <simgear/math/point3d.hxx>
#include <simgear/math/polar3d.hxx>
#include <simgear/math/sg_geodesy.hxx>
#include <Scenery/scenery.hxx>
/* from lookat */
#include <simgear/math/vector.hxx>
#include "globals.hxx"
/* end from lookat */
#include "viewer.hxx"
////////////////////////////////////////////////////////////////////////
// Implementation of FGViewer.
////////////////////////////////////////////////////////////////////////
// Constructor
FGViewer::FGViewer( void ):
scalingType(FG_SCALING_MAX),
fov(55.0),
goal_view_offset(0.0),
goal_view_tilt(0.0),
_dirty(true),
_lon_deg(0),
_lat_deg(0),
_alt_ft(0),
_target_lon_deg(0),
_target_lat_deg(0),
_target_alt_ft(0),
_roll_deg(0),
_pitch_deg(0),
_heading_deg(0),
_x_offset_m(0),
_y_offset_m(0),
_z_offset_m(0),
_heading_offset_deg(0),
_pitch_offset_deg(0),
_roll_offset_deg(0)
{
sgdZeroVec3(_absolute_view_pos);
sea_level_radius = SG_EQUATORIAL_RADIUS_M;
//a reasonable guess for init, so that the math doesn't blow up
}
// Destructor
FGViewer::~FGViewer( void ) {
}
void
FGViewer::init ()
{
if ( _type == FG_LOOKAT ) {
set_reverse_view_offset(true);
}
if ( _type == FG_RPH ) {
set_reverse_view_offset(false);
}
}
void
FGViewer::bind ()
{
}
void
FGViewer::unbind ()
{
}
void
FGViewer::setType ( int type )
{
if (type == 0)
_type = FG_RPH;
if (type == 1)
_type = FG_LOOKAT;
}
void
FGViewer::setLongitude_deg (double lon_deg)
{
_dirty = true;
_lon_deg = lon_deg;
}
void
FGViewer::setLatitude_deg (double lat_deg)
{
_dirty = true;
_lat_deg = lat_deg;
}
void
FGViewer::setAltitude_ft (double alt_ft)
{
_dirty = true;
_alt_ft = alt_ft;
}
void
FGViewer::setPosition (double lon_deg, double lat_deg, double alt_ft)
{
_dirty = true;
_lon_deg = lon_deg;
_lat_deg = lat_deg;
_alt_ft = alt_ft;
}
void
FGViewer::setTargetLongitude_deg (double lon_deg)
{
_dirty = true;
_target_lon_deg = lon_deg;
}
void
FGViewer::setTargetLatitude_deg (double lat_deg)
{
_dirty = true;
_target_lat_deg = lat_deg;
}
void
FGViewer::setTargetAltitude_ft (double alt_ft)
{
_dirty = true;
_target_alt_ft = alt_ft;
}
void
FGViewer::setTargetPosition (double lon_deg, double lat_deg, double alt_ft)
{
_dirty = true;
_target_lon_deg = lon_deg;
_target_lat_deg = lat_deg;
_target_alt_ft = alt_ft;
}
void
FGViewer::setRoll_deg (double roll_deg)
{
_dirty = true;
_roll_deg = roll_deg;
}
void
FGViewer::setPitch_deg (double pitch_deg)
{
_dirty = true;
_pitch_deg = pitch_deg;
}
void
FGViewer::setHeading_deg (double heading_deg)
{
_dirty = true;
_heading_deg = heading_deg;
}
void
FGViewer::setOrientation (double roll_deg, double pitch_deg, double heading_deg)
{
_dirty = true;
_roll_deg = roll_deg;
_pitch_deg = pitch_deg;
_heading_deg = heading_deg;
}
void
FGViewer::setXOffset_m (double x_offset_m)
{
_dirty = true;
_x_offset_m = x_offset_m;
}
void
FGViewer::setYOffset_m (double y_offset_m)
{
_dirty = true;
_y_offset_m = y_offset_m;
}
void
FGViewer::setZOffset_m (double z_offset_m)
{
_dirty = true;
_z_offset_m = z_offset_m;
}
void
FGViewer::setPositionOffsets (double x_offset_m, double y_offset_m, double z_offset_m)
{
_dirty = true;
_x_offset_m = x_offset_m;
_y_offset_m = y_offset_m;
_z_offset_m = z_offset_m;
}
void
FGViewer::setRollOffset_deg (double roll_offset_deg)
{
_dirty = true;
_roll_offset_deg = roll_offset_deg;
}
void
FGViewer::setPitchOffset_deg (double pitch_offset_deg)
{
_dirty = true;
_pitch_offset_deg = pitch_offset_deg;
}
void
FGViewer::setHeadingOffset_deg (double heading_offset_deg)
{
_dirty = true;
_heading_offset_deg = heading_offset_deg;
}
void
FGViewer::setOrientationOffsets (double roll_offset_deg, double pitch_offset_deg, double heading_offset_deg)
{
_dirty = true;
_roll_offset_deg = roll_offset_deg;
_pitch_offset_deg = pitch_offset_deg;
_heading_offset_deg = heading_offset_deg;
}
double *
FGViewer::get_absolute_view_pos ()
{
if (_dirty)
recalc();
return _absolute_view_pos;
}
float *
FGViewer::getRelativeViewPos ()
{
if (_dirty)
recalc();
return _relative_view_pos;
}
float *
FGViewer::getZeroElevViewPos ()
{
if (_dirty)
recalc();
return _zero_elev_view_pos;
}
// recalc() is done every time one of the setters is called (making the
// cached data "dirty"). It calculates all the outputs for viewer.
void
FGViewer::recalc ()
{
sgVec3 minus_z, right, forward, tilt;
sgMat4 VIEWo;
sgMat4 tmpROT; // temp rotation work matrices
sgVec3 tmpVec3; // temp work vector (3)
// The position vectors originate from the view point or target location
// depending on the type of view.
if (_type == FG_RPH) {
recalcPositionVectors( _lon_deg, _lat_deg, _alt_ft );
} else {
recalcPositionVectors( _target_lon_deg, _target_lat_deg, _target_alt_ft );
}
sgCopyVec3(zero_elev, _zero_elev_view_pos);
sgCopyVec3(view_pos, _relative_view_pos);
if (_type == FG_LOOKAT) {
// Make the world up rotation matrix for lookat
sgMakeRotMat4( UP, _target_lon_deg, 0.0, -_target_lat_deg );
// get the world up verctor from the worldup rotation matrix
sgSetVec3( world_up, UP[0][0], UP[0][1], UP[0][2] );
sgCopyVec3( view_up, world_up );
// create offset vector
sgVec3 lookat_offset;
sgSetVec3( lookat_offset, _x_offset_m, _y_offset_m, _z_offset_m );
// Apply heading orientation and orientation offset to lookat_offset...
sgMakeRotMat4( tmpROT, _heading_offset_deg -_heading_deg, world_up);
sgXformVec3( lookat_offset, lookat_offset, UP );
sgXformVec3( lookat_offset, lookat_offset, tmpROT );
// Apply orientation offset tilt...
// FIXME: Need to get and use a "right" vector instead of 1-0-0
sgSetVec3 (tmpVec3, 1, 0, 0);
sgMakeRotMat4( tmpROT, _pitch_offset_deg, tmpVec3 );
sgXformPnt3( lookat_offset, lookat_offset, tmpROT );
// add the offsets including rotations to the coordinates
sgAddVec3( view_pos, lookat_offset );
// Make the VIEW matrix.
fgMakeLookAtMat4( VIEW, view_pos, view_forward, view_up );
// 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;
}
if (_type == FG_RPH) {
// code to calculate LOCAL matrix calculated from Phi, Theta, and
// Psi (roll, pitch, yaw) in case we aren't running LaRCsim as our
// flight model
fgMakeLOCAL( LOCAL, _pitch_deg * SG_DEGREES_TO_RADIANS,
_roll_deg * SG_DEGREES_TO_RADIANS,
-_heading_deg * SG_DEGREES_TO_RADIANS);
// Make the world up rotation matrix for pilot view
sgMakeRotMat4( UP, _lon_deg, 0.0, -_lat_deg );
// get the world up verctor from the worldup rotation matrix
sgSetVec3( world_up, UP[0][0], UP[0][1], UP[0][2] );
// VIEWo becomes the rotation matrix with world_up incorporated
sgCopyMat4( VIEWo, LOCAL );
sgPostMultMat4( VIEWo, UP );
// generate the sg view up and forward vectors
sgSetVec3( view_up, VIEWo[0][0], VIEWo[0][1], VIEWo[0][2] );
sgSetVec3( right, VIEWo[1][0], VIEWo[1][1], VIEWo[1][2] );
sgSetVec3( forward, VIEWo[2][0], VIEWo[2][1], VIEWo[2][2] );
// apply the offsets in world coordinates
sgVec3 pilot_offset_world;
sgSetVec3( pilot_offset_world,
_z_offset_m, _y_offset_m, -_x_offset_m );
sgXformVec3( pilot_offset_world, pilot_offset_world, VIEWo );
// generate the view offset matrix using orientation offset (heading)
sgMakeRotMat4( VIEW_OFFSET, _heading_offset_deg, view_up );
// create a tilt matrix using orientation offset (pitch)
sgMat4 VIEW_TILT;
sgMakeRotMat4( VIEW_TILT, _pitch_offset_deg, right );
sgPreMultMat4(VIEW_OFFSET, VIEW_TILT);
sgXformVec3( view_forward, forward, VIEW_OFFSET );
SG_LOG( SG_VIEW, SG_DEBUG, "(RPH) view forward = "
<< view_forward[0] << "," << view_forward[1] << ","
<< view_forward[2] );
// VIEW_ROT = LARC_TO_SSG * ( VIEWo * VIEW_OFFSET )
fgMakeViewRot( VIEW_ROT, VIEW_OFFSET, VIEWo );
sgVec3 trans_vec;
sgAddVec3( trans_vec, view_pos, pilot_offset_world );
// VIEW = VIEW_ROT * TRANS
sgCopyMat4( VIEW, VIEW_ROT );
sgPostMultMat4ByTransMat4( VIEW, trans_vec );
}
// 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);
// now calculate the surface east vector
sgVec3 world_down;
sgNegateVec3(world_down, world_up);
sgVectorProductVec3(surface_east, surface_south, world_down);
set_clean();
}
void
FGViewer::recalcPositionVectors (double lon_deg, double lat_deg, double alt_ft) const
{
double sea_level_radius_m;
double lat_geoc_rad;
// Convert from geodetic to geocentric
// coordinates.
sgGeodToGeoc(lat_deg * SGD_DEGREES_TO_RADIANS,
alt_ft * SG_FEET_TO_METER,
&sea_level_radius_m,
&lat_geoc_rad);
// Calculate the cartesian coordinates
// of point directly below at sea level.
// aka Zero Elevation Position
Point3D p = Point3D(lon_deg * SG_DEGREES_TO_RADIANS,
lat_geoc_rad,
sea_level_radius_m);
Point3D tmp = sgPolarToCart3d(p) - scenery.get_next_center();
sgSetVec3(_zero_elev_view_pos, tmp[0], tmp[1], tmp[2]);
// Calculate the absolute view position
// in fgfs coordinates.
// aka Absolute View Position
p.setz(p.radius() + alt_ft * SG_FEET_TO_METER);
tmp = sgPolarToCart3d(p);
sgdSetVec3(_absolute_view_pos, tmp[0], tmp[1], tmp[2]);
// Calculate the relative view position
// from the scenery center.
// aka Relative View Position
sgdVec3 scenery_center;
sgdSetVec3(scenery_center,
scenery.get_next_center().x(),
scenery.get_next_center().y(),
scenery.get_next_center().z());
sgdVec3 view_pos;
sgdSubVec3(view_pos, _absolute_view_pos, scenery_center);
sgSetVec3(_relative_view_pos, view_pos);
}
double
FGViewer::get_h_fov()
{
switch (scalingType) {
case FG_SCALING_WIDTH: // h_fov == fov
return fov;
case FG_SCALING_MAX:
if (aspect_ratio < 1.0) {
// h_fov == fov
return fov;
} else {
// v_fov == fov
return atan(tan(fov/2 * SG_DEGREES_TO_RADIANS) / aspect_ratio) *
SG_RADIANS_TO_DEGREES * 2;
}
default:
assert(false);
}
}
double
FGViewer::get_v_fov()
{
switch (scalingType) {
case FG_SCALING_WIDTH: // h_fov == fov
return atan(tan(fov/2 * SG_DEGREES_TO_RADIANS) * aspect_ratio) *
SG_RADIANS_TO_DEGREES * 2;
case FG_SCALING_MAX:
if (aspect_ratio < 1.0) {
// h_fov == fov
return atan(tan(fov/2 * SG_DEGREES_TO_RADIANS) * aspect_ratio) *
SG_RADIANS_TO_DEGREES * 2;
} else {
// v_fov == fov
return fov;
}
default:
assert(false);
}
}
void
FGViewer::update (int dt)
{
int i;
for ( i = 0; i < dt; i++ ) {
if ( fabs(get_goal_view_offset() - getHeadingOffset_deg()) < 1 ) {
setHeadingOffset_deg( get_goal_view_offset() );
break;
} else {
// move current_view.headingoffset towards
// current_view.goal_view_offset
if ( get_goal_view_offset() > getHeadingOffset_deg() )
{
if ( get_goal_view_offset() - getHeadingOffset_deg() < 180 ){
inc_view_offset( 0.5 );
} else {
inc_view_offset( -0.5 );
}
} else {
if ( getHeadingOffset_deg() - get_goal_view_offset() < 180 ){
inc_view_offset( -0.5 );
} else {
inc_view_offset( 0.5 );
}
}
if ( getHeadingOffset_deg() > 360 ) {
inc_view_offset( -360 );
} else if ( getHeadingOffset_deg() < 0 ) {
inc_view_offset( 360 );
}
}
}
for ( i = 0; i < dt; i++ ) {
if ( fabs(get_goal_view_tilt() - getPitchOffset_deg()) < 1 ) {
setPitchOffset_deg( get_goal_view_tilt() );
break;
} else {
// move current_view.pitch_offset_deg towards
// current_view.goal_view_tilt
if ( get_goal_view_tilt() > getPitchOffset_deg() )
{
if ( get_goal_view_tilt() - getPitchOffset_deg() < 0 ){
inc_view_tilt( 1.0 );
} else {
inc_view_tilt( -1.0 );
}
} else {
if ( getPitchOffset_deg() - get_goal_view_tilt() < 0 ){
inc_view_tilt( -1.0 );
} else {
inc_view_tilt( 1.0 );
}
}
if ( getPitchOffset_deg() > 90 ) {
setPitchOffset_deg(90);
} else if ( getPitchOffset_deg() < -90 ) {
setPitchOffset_deg( -90 );
}
}
}
}
void FGViewer::fgMakeLookAtMat4 ( sgMat4 dst, const sgVec3 eye, const sgVec3 center,
const sgVec3 up )
{
// Caveats:
// 1) In order to compute the line of sight, the eye point must not be equal
// to the center point.
// 2) The up vector must not be parallel to the line of sight from the eye
// to the center point.
/* Compute the direction vectors */
sgVec3 x,y,z;
/* Y vector = center - eye */
sgSubVec3 ( y, center, eye ) ;
/* Z vector = up */
sgCopyVec3 ( z, up ) ;
/* X vector = Y cross Z */
sgVectorProductVec3 ( x, y, z ) ;
/* Recompute Z = X cross Y */
sgVectorProductVec3 ( z, x, y ) ;
/* Normalize everything */
sgNormaliseVec3 ( x ) ;
sgNormaliseVec3 ( y ) ;
sgNormaliseVec3 ( z ) ;
/* Build the matrix */
#define M(row,col) dst[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
}
/* end from lookat */
/* from rph */
// VIEW_ROT = LARC_TO_SSG * ( VIEWo * VIEW_OFFSET )
// This takes advantage of the fact that VIEWo and VIEW_OFFSET
// only have entries in the upper 3x3 block
// and that LARC_TO_SSG is just a shift of rows NHV
void FGViewer::fgMakeViewRot( sgMat4 dst, const sgMat4 m1, const sgMat4 m2 )
{
for ( int j = 0 ; j < 3 ; j++ ) {
dst[2][j] = m2[0][0] * m1[0][j] +
m2[0][1] * m1[1][j] +
m2[0][2] * m1[2][j];
dst[0][j] = m2[1][0] * m1[0][j] +
m2[1][1] * m1[1][j] +
m2[1][2] * m1[2][j];
dst[1][j] = m2[2][0] * m1[0][j] +
m2[2][1] * m1[1][j] +
m2[2][2] * m1[2][j];
}
dst[0][3] =
dst[1][3] =
dst[2][3] =
dst[3][0] =
dst[3][1] =
dst[3][2] = SG_ZERO;
dst[3][3] = SG_ONE;
}
void FGViewer::fgMakeLOCAL( sgMat4 dst, const double Theta,
const double Phi, const double Psi)
{
SGfloat cosTheta = (SGfloat) cos(Theta);
SGfloat sinTheta = (SGfloat) sin(Theta);
SGfloat cosPhi = (SGfloat) cos(Phi);
SGfloat sinPhi = (SGfloat) sin(Phi);
SGfloat sinPsi = (SGfloat) sin(Psi) ;
SGfloat cosPsi = (SGfloat) cos(Psi) ;
dst[0][0] = cosPhi * cosTheta;
dst[0][1] = sinPhi * cosPsi + cosPhi * -sinTheta * -sinPsi;
dst[0][2] = sinPhi * sinPsi + cosPhi * -sinTheta * cosPsi;
dst[0][3] = SG_ZERO;
dst[1][0] = -sinPhi * cosTheta;
dst[1][1] = cosPhi * cosPsi + -sinPhi * -sinTheta * -sinPsi;
dst[1][2] = cosPhi * sinPsi + -sinPhi * -sinTheta * cosPsi;
dst[1][3] = SG_ZERO ;
dst[2][0] = sinTheta;
dst[2][1] = cosTheta * -sinPsi;
dst[2][2] = cosTheta * cosPsi;
dst[2][3] = SG_ZERO;
dst[3][0] = SG_ZERO;
dst[3][1] = SG_ZERO;
dst[3][2] = SG_ZERO;
dst[3][3] = SG_ONE ;
}
/* end from rph */