#include

#include "light.hxx" #include "sunpos.hxx" // Constructor FGLight::FGLight () : _prev_sun_angle(-9999.0), _dt_total( 0.0 ) { } // Destructor FGLight::~FGLight () { } // 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; fgUpdateSunPos(); fgUpdateMoonPos(); update_sky_color(); update_adj_fog_color(); } void FGLight::bind () { } void FGLight::unbind () { } // update lighting parameters based on current sun position void FGLight::update( double dt ) { update_adj_fog_color(); _dt_total += dt; if (_dt_total >= 0.5) { _dt_total -= 0.5; fgUpdateSunPos(); fgUpdateMoonPos(); } 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] = { 0.39, 0.50, 0.74, 1.0 }; const GLfloat base_fog_color[4] = { 0.84, 0.87, 1.0, 1.0 }; SG_LOG( SG_EVENT, SG_INFO, "Updating light parameters." ); // calculate lighting parameters based on sun's relative angle to // local up float deg = _sun_angle * SGD_RADIANS_TO_DEGREES; SG_LOG( SG_EVENT, SG_INFO, " Sun angle = " << deg ); float ambient = _ambient_tbl->interpolate( deg ); float diffuse = _diffuse_tbl->interpolate( deg ); float specular = _specular_tbl->interpolate( deg ); float sky_brightness = _sky_tbl->interpolate( deg ); SG_LOG( SG_EVENT, SG_INFO, " ambient = " << ambient << " diffuse = " << diffuse << " specular = " << specular << " sky = " << sky_brightness ); // sky_brightness = 0.15; // used to force a dark sky (when testing) // if ( ambient < 0.02 ) { ambient = 0.02; } // if ( diffuse < 0.0 ) { diffuse = 0.0; } // if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; } // 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 ); // set cloud and fog color _cloud_color[0] = _fog_color[0] = base_fog_color[0] * sky_brightness; _cloud_color[1] = _fog_color[1] = base_fog_color[1] * sky_brightness; _cloud_color[2] = _fog_color[2] = base_fog_color[2] * sky_brightness; _cloud_color[3] = _fog_color[3] = base_fog_color[3]; gamma_correct_rgb( _fog_color ); // 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 ); float *sun_color = thesky->get_sun_color(); _scene_ambient[0] = ((sun_color[0]*0.25 + _cloud_color[0]*0.75) + ambient) / 2; _scene_ambient[1] = ((sun_color[1]*0.25 + _cloud_color[1]*0.75) + ambient) / 2; _scene_ambient[2] = ((sun_color[2]*0.25 + _cloud_color[2]*0.75) + ambient) / 2; _scene_ambient[3] = 1.0; _scene_diffuse[0] = (sun_color[0]*0.25 + _fog_color[0]*0.75) * diffuse; _scene_diffuse[1] = (sun_color[1]*0.25 + _fog_color[1]*0.75) * diffuse; _scene_diffuse[2] = (sun_color[2]*0.25 + _fog_color[2]*0.75) * diffuse; _scene_diffuse[3] = 1.0; _scene_specular[0] = sun_color[0] * specular; _scene_specular[1] = sun_color[1] * specular; _scene_specular[2] = sun_color[2] * specular; _scene_specular[3] = 1.0; } // calculate fog color adjusted for sunrise/sunset effects void FGLight::update_adj_fog_color () { 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 ); exit(-1); } if ( heading < -2.0 * SGD_2PI || heading > 2.0 * SGD_2PI ) { SG_LOG( SG_EVENT, SG_ALERT, "Heading rotation bad = " << heading ); exit(-1); } if ( heading_offset < -2.0 * SGD_2PI || heading_offset > 2.0 * SGD_2PI ) { SG_LOG( SG_EVENT, SG_ALERT, "Heading offset bad = " << heading_offset ); exit(-1); } double rotation; // first determine the difference between our view angle and local // direction to the sun rotation = -(_sun_rotation + SGD_PI) - heading + heading_offset; while ( rotation < 0 ) { rotation += SGD_2PI; } while ( rotation > SGD_2PI ) { rotation -= SGD_2PI; } // revert to unmodified values before usign them. // float *sun_color = thesky->get_sun_color(); gamma_restore_rgb( _fog_color ); // Calculate the fog color in the direction of the sun for // sunrise/sunset effects. // float s_red = (_fog_color[0] + 2 * sun_color[0]*sun_color[0]) / 3; float s_green = (_fog_color[1] + 2 * sun_color[1]*sun_color[1]) / 3; float s_blue = (_fog_color[2] + 2 * sun_color[2]) / 3; // 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; float rf1 = fabs((rotation - SGD_PI) / SGD_PI); // 0.0 .. 1.0 float rf2 = avf * pow(rf1 * rf1, 1/sif); float rf3 = 0.94 - rf2; _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 ); // make sure the colors have their original value before they are being // used by the rest of the program. // gamma_correct_rgb( _fog_color ); }