//
// light.cxx -- lighting routines
//
// Written by Curtis Olson, started April 1998.
//
// Copyright (C) 1998 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 <config.h>
#endif
#include <simgear/compiler.h>
#include <cmath>
#include <simgear/constants.h>
#include <simgear/debug/logstream.hxx>
#include <simgear/math/interpolater.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/scene/sky/sky.hxx>
#include <simgear/screen/colors.hxx>
#include <Main/main.hxx>
#include <Main/globals.hxx>
#include <Main/fg_props.hxx>
#include <Main/renderer.hxx>
#include <Main/viewer.hxx>
#include "light.hxx"
#include "tmp.hxx"
// Constructor
FGLight::FGLight ()
: _ambient_tbl( NULL ),
_diffuse_tbl( NULL ),
_specular_tbl( NULL ),
_sky_tbl( NULL ),
_sun_lon(0),
_sun_lat(0),
_moon_lon(0),
_moon_gc_lat(0),
_sun_vec(0, 0, 0, 0),
_moon_vec(0, 0, 0, 0),
_sun_vec_inv(0, 0, 0, 0),
_moon_vec_inv(0, 0, 0, 0),
_sun_angle(0),
_moon_angle(0),
_prev_sun_angle(0),
_sun_rotation(0),
_moon_rotation(0),
_scene_ambient(0, 0, 0, 0),
_scene_diffuse(0, 0, 0, 0),
_scene_specular(0, 0, 0, 0),
_scene_chrome(0, 0, 0, 0),
_sky_color(0, 0, 0, 0),
_fog_color(0, 0, 0, 0),
_cloud_color(0, 0, 0, 0),
_adj_fog_color(0, 0, 0, 0),
_adj_sky_color(0, 0, 0, 0),
_dt_total(0)
{
}
// Destructor
FGLight::~FGLight ()
{
delete _ambient_tbl;
delete _diffuse_tbl;
delete _specular_tbl;
delete _sky_tbl;
}
// initialize lighting tables
void FGLight::init () {
SG_LOG( SG_EVENT, SG_INFO,
"Initializing Lighting interpolation tables." );
// build the path names of the lookup tables
SGPath path( globals->get_fg_root() );
// initialize ambient, diffuse and specular tables
SGPath ambient_path = path;
ambient_path.append( "Lighting/ambient" );
_ambient_tbl = new SGInterpTable( ambient_path.str() );
SGPath diffuse_path = path;
diffuse_path.append( "Lighting/diffuse" );
_diffuse_tbl = new SGInterpTable( diffuse_path.str() );
SGPath specular_path = path;
specular_path.append( "Lighting/specular" );
_specular_tbl = new SGInterpTable( specular_path.str() );
// initialize sky table
SGPath sky_path = path;
sky_path.append( "Lighting/sky" );
_sky_tbl = new SGInterpTable( sky_path.str() );
}
void FGLight::reinit () {
_prev_sun_angle = -9999.0;
_dt_total = 0;
delete _ambient_tbl;
delete _diffuse_tbl;
delete _specular_tbl;
delete _sky_tbl;
init();
fgUpdateSunPos();
update_sky_color();
update_adj_fog_color();
}
void FGLight::bind () {
SGPropertyNode *prop = globals->get_props();
prop->tie("/sim/time/sun-angle-rad",SGRawValuePointer<double>(&_sun_angle));
prop->tie("/rendering/scene/ambient/red",SGRawValuePointer<float>(&_scene_ambient[0]));
prop->tie("/rendering/scene/ambient/green",SGRawValuePointer<float>(&_scene_ambient[1]));
prop->tie("/rendering/scene/ambient/blue",SGRawValuePointer<float>(&_scene_ambient[2]));
prop->tie("/rendering/scene/diffuse/red",SGRawValuePointer<float>(&_scene_diffuse[0]));
prop->tie("/rendering/scene/diffuse/green",SGRawValuePointer<float>(&_scene_diffuse[1]));
prop->tie("/rendering/scene/diffuse/blue",SGRawValuePointer<float>(&_scene_diffuse[2]));
prop->tie("/rendering/scene/specular/red",SGRawValuePointer<float>(&_scene_specular[0]));
prop->tie("/rendering/scene/specular/green",SGRawValuePointer<float>(&_scene_specular[1]));
prop->tie("/rendering/scene/specular/blue",SGRawValuePointer<float>(&_scene_specular[2]));
prop->tie("/rendering/dome/sky/red",SGRawValuePointer<float>(&_sky_color[0]));
prop->tie("/rendering/dome/sky/green",SGRawValuePointer<float>(&_sky_color[1]));
prop->tie("/rendering/dome/sky/blue",SGRawValuePointer<float>(&_sky_color[2]));
prop->tie("/rendering/dome/fog/red",SGRawValuePointer<float>(&_fog_color[0]));
prop->tie("/rendering/dome/fog/green",SGRawValuePointer<float>(&_fog_color[1]));
prop->tie("/rendering/dome/fog/blue",SGRawValuePointer<float>(&_fog_color[2]));
// Properties used directly by effects
_chromeProps[0] = prop->getNode("/rendering/scene/chrome-light/red", true);
_chromeProps[1] = prop->getNode("/rendering/scene/chrome-light/green",
true);
_chromeProps[2] = prop->getNode("/rendering/scene/chrome-light/blue", true);
_chromeProps[3] = prop->getNode("/rendering/scene/chrome-light/alpha",
true);
for (int i = 0; i < 4; ++i)
_chromeProps[i]->setValue(0.0);
}
void FGLight::unbind () {
SGPropertyNode *prop = globals->get_props();
prop->untie("/sim/time/sun-angle-rad");
prop->untie("/rendering/scene/ambient/red");
prop->untie("/rendering/scene/ambient/green");
prop->untie("/rendering/scene/ambient/blue");
prop->untie("/rendering/scene/diffuse/red");
prop->untie("/rendering/scene/diffuse/green");
prop->untie("/rendering/scene/diffuse/blue");
prop->untie("/rendering/scene/specular/red");
prop->untie("/rendering/scene/specular/green");
prop->untie("/rendering/scene/specular/blue");
prop->untie("/rendering/dome/sun/red");
prop->untie("/rendering/dome/sun/green");
prop->untie("/rendering/dome/sun/blue");
prop->untie("/rendering/dome/sky/red");
prop->untie("/rendering/dome/sky/green");
prop->untie("/rendering/dome/sky/blue");
prop->untie("/rendering/dome/fog/red");
prop->untie("/rendering/dome/fog/green");
prop->untie("/rendering/dome/fog/blue");
}
// update lighting parameters based on current sun position
void FGLight::update( double dt ) {
_dt_total += dt;
if (_dt_total >= 0.5) {
_dt_total -= 0.5;
fgUpdateSunPos();
}
update_adj_fog_color();
if (_prev_sun_angle != _sun_angle) {
_prev_sun_angle = _sun_angle;
update_sky_color();
}
}
void FGLight::update_sky_color () {
// if the 4th field is 0.0, this specifies a direction ...
// const GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
const GLfloat base_sky_color[4] = { 0.31, 0.43, 0.69, 1.0 };
const GLfloat base_fog_color[4] = { 0.63, 0.72, 0.88, 1.0 };
SG_LOG( SG_EVENT, SG_DEBUG, "Updating light parameters." );
// calculate lighting parameters based on sun's relative angle to
// local up
static SGConstPropertyNode_ptr humidity = fgGetNode("/environment/relative-humidity");
float av = humidity->getFloatValue() * 45;
float visibility_log = log(av)/11.0;
float visibility_inv = (45000.0 - av)/45000.0;
float deg = _sun_angle * SGD_RADIANS_TO_DEGREES;
SG_LOG( SG_EVENT, SG_DEBUG, " Sun angle = " << deg );
float ambient = _ambient_tbl->interpolate( deg ) + visibility_inv/10;
float diffuse = _diffuse_tbl->interpolate( deg );
float specular = _specular_tbl->interpolate( deg ) * visibility_log;
float sky_brightness = _sky_tbl->interpolate( deg );
SG_LOG( SG_EVENT, SG_DEBUG,
" ambient = " << ambient << " diffuse = " << diffuse
<< " specular = " << specular << " sky = " << sky_brightness );
// sky_brightness = 0.15; // used to force a dark sky (when testing)
// set fog and cloud color
float sqrt_sky_brightness = 1.0 - sqrt(1.0 - sky_brightness);
_fog_color[0] = base_fog_color[0] * sqrt_sky_brightness;
_fog_color[1] = base_fog_color[1] * sqrt_sky_brightness;
_fog_color[2] = base_fog_color[2] * sqrt_sky_brightness;
_fog_color[3] = base_fog_color[3];
gamma_correct_rgb( _fog_color.data() );
// set sky color
_sky_color[0] = base_sky_color[0] * sky_brightness;
_sky_color[1] = base_sky_color[1] * sky_brightness;
_sky_color[2] = base_sky_color[2] * sky_brightness;
_sky_color[3] = base_sky_color[3];
gamma_correct_rgb( _sky_color.data() );
_cloud_color[0] = base_fog_color[0] * sky_brightness;
_cloud_color[1] = base_fog_color[1] * sky_brightness;
_cloud_color[2] = base_fog_color[2] * sky_brightness;
_cloud_color[3] = base_fog_color[3];
// adjust the cloud colors for sunrise/sunset effects (darken them)
if (_sun_angle > 1.0) {
float sun2 = sqrt(_sun_angle);
_cloud_color[0] /= sun2;
_cloud_color[1] /= sun2;
_cloud_color[2] /= sun2;
}
gamma_correct_rgb( _cloud_color.data() );
_scene_ambient[0] = _fog_color[0] * ambient;
_scene_ambient[1] = _fog_color[1] * ambient;
_scene_ambient[2] = _fog_color[2] * ambient;
_scene_ambient[3] = 1.0;
gamma_correct_rgb( _scene_ambient.data() );
SGVec4f color = thesky->get_scene_color();
_scene_diffuse[0] = color[0] * diffuse;
_scene_diffuse[1] = color[1] * diffuse;
_scene_diffuse[2] = color[2] * diffuse;
_scene_diffuse[3] = 1.0;
gamma_correct_rgb( _scene_diffuse.data() );
SGVec4f chrome = _scene_ambient * .4f + _scene_diffuse;
chrome[3] = 1.0f;
if (chrome != _scene_chrome) {
_scene_chrome = chrome;
for (int i = 0; i < 4; ++i)
_chromeProps[i]->setValue(static_cast<double>(_scene_chrome[i]));
}
color = thesky->get_sun_color();
_scene_specular[0] = color[0] * specular;
_scene_specular[1] = color[1] * specular;
_scene_specular[2] = color[2] * specular;
_scene_specular[3] = 1.0;
gamma_correct_rgb( _scene_specular.data() );
}
// calculate fog color adjusted for sunrise/sunset effects
void FGLight::update_adj_fog_color () {
double pitch = globals->get_current_view()->getPitch_deg()
* SGD_DEGREES_TO_RADIANS;
double pitch_offset = globals->get_current_view()-> getPitchOffset_deg()
* SGD_DEGREES_TO_RADIANS;
double heading = globals->get_current_view()->getHeading_deg()
* SGD_DEGREES_TO_RADIANS;
double heading_offset = globals->get_current_view()->getHeadingOffset_deg()
* SGD_DEGREES_TO_RADIANS;
SG_LOG( SG_EVENT, SG_DEBUG, "Updating adjusted fog parameters." );
// set fog color (we'll try to match the sunset color in the
// direction we are looking
// Do some sanity checking ...
if ( _sun_rotation < -2.0 * SGD_2PI || _sun_rotation > 2.0 * SGD_2PI ) {
SG_LOG( SG_EVENT, SG_ALERT, "Sun rotation bad = " << _sun_rotation );
return;
}
if ( heading < -2.0 * SGD_2PI || heading > 2.0 * SGD_2PI ) {
SG_LOG( SG_EVENT, SG_ALERT, "Heading rotation bad = " << heading );
return;
}
if ( heading_offset < -2.0 * SGD_2PI || heading_offset > 2.0 * SGD_2PI ) {
SG_LOG( SG_EVENT, SG_ALERT, "Heading offset bad = " << heading_offset );
return;
}
double hor_rotation, vert_rotation;
static float gamma = system_gamma;
// first determine the difference between our view angle and local
// direction to the sun
vert_rotation = pitch + pitch_offset;
hor_rotation = -(_sun_rotation + SGD_PI) - heading + heading_offset;
if (hor_rotation < 0 )
hor_rotation = fmod(hor_rotation, SGD_2PI) + SGD_2PI;
else
hor_rotation = fmod(hor_rotation, SGD_2PI);
// revert to unmodified values before usign them.
//
SGVec4f color = thesky->get_scene_color();
gamma_restore_rgb( _fog_color.data(), gamma );
gamma_restore_rgb( _sky_color.data(), gamma );
// Calculate the fog color in the direction of the sun for
// sunrise/sunset effects.
//
float s_red = color[0]*color[0]*color[0];
float s_green = color[1]*color[1]*color[1];
float s_blue = color[2]*color[2];
// interpolate beween the sunrise/sunset color and the color
// at the opposite direction of this effect. Take in account
// the current visibility.
//
float av = thesky->get_visibility();
if (av > 45000) av = 45000;
float avf = 0.87 - (45000 - av) / 83333.33;
float sif = 0.5 - cos(_sun_angle*2)/2;
if (sif < 1e-4)
sif = 1e-4;
float rf1 = fabs((hor_rotation - SGD_PI) / SGD_PI); // 0.0 .. 1.0
float rf2 = avf * pow(rf1*rf1, 1/sif) * 1.0639;
float rf3 = 1.0 - rf2;
gamma = system_gamma * (0.9 - sif*avf);
_adj_fog_color[0] = rf3 * _fog_color[0] + rf2 * s_red;
_adj_fog_color[1] = rf3 * _fog_color[1] + rf2 * s_green;
_adj_fog_color[2] = rf3 * _fog_color[2] + rf2 * s_blue;
gamma_correct_rgb( _adj_fog_color.data(), gamma);
// make sure the colors have their original value before they are being
// used by the rest of the program.
//
gamma_correct_rgb( _fog_color.data(), gamma );
gamma_correct_rgb( _sky_color.data(), gamma );
}