// // light.hxx -- lighting routines // // Written by Curtis Olson, started April 1998. // // Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu // // 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. // // $Id$ #ifdef HAVE_CONFIG_H # include #endif #ifdef HAVE_WINDOWS_H # include #endif #include #include #include #ifdef FG_MATH_EXCEPTION_CLASH # define exception c_exception #endif #ifdef FG_HAVE_STD_INCLUDES # include #else # include #endif #include FG_USING_STD(string); #include #include #include #include #include #include #include #include #include
#include
#include "fg_time.hxx" #include "light.hxx" #include "sunpos.hxx" fgLIGHT cur_light_params; // Constructor fgLIGHT::fgLIGHT( void ) { } // initialize lighting tables void fgLIGHT::Init( void ) { FG_LOG( FG_EVENT, FG_INFO, "Initializing Lighting interpolation tables." ); // build the path name to the ambient lookup table FGPath path( current_options.get_fg_root() ); FGPath ambient = path; ambient.append( "Lighting/ambient" ); FGPath diffuse = path; diffuse.append( "Lighting/diffuse" ); FGPath sky = path; sky.append( "Lighting/sky" ); // initialize ambient table ambient_tbl = new fgINTERPTABLE( ambient.str() ); // initialize diffuse table diffuse_tbl = new fgINTERPTABLE( diffuse.str() ); // initialize sky table sky_tbl = new fgINTERPTABLE( sky.str() ); } // update lighting parameters based on current sun position void fgLIGHT::Update( void ) { FGInterface *f; FGTime *t; // if the 4th field is 0.0, this specifies a direction ... GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 }; // base sky color GLfloat base_sky_color[4] = {0.60, 0.60, 0.90, 1.0}; // base fog color GLfloat base_fog_color[4] = {0.90, 0.90, 1.00, 1.0}; double deg, ambient, diffuse, sky_brightness; f = current_aircraft.fdm_state; t = FGTime::cur_time_params; FG_LOG( FG_EVENT, FG_INFO, "Updating light parameters." ); // calculate lighting parameters based on sun's relative angle to // local up deg = sun_angle * 180.0 / FG_PI; FG_LOG( FG_EVENT, FG_INFO, " Sun angle = " << deg ); ambient = ambient_tbl->interpolate( deg ); diffuse = diffuse_tbl->interpolate( deg ); sky_brightness = sky_tbl->interpolate( deg ); FG_LOG( FG_EVENT, FG_INFO, " ambient = " << ambient << " diffuse = " << diffuse << " 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; } scene_ambient[0] = white[0] * ambient; scene_ambient[1] = white[1] * ambient; scene_ambient[2] = white[2] * ambient; scene_diffuse[0] = white[0] * diffuse; scene_diffuse[1] = white[1] * diffuse; scene_diffuse[2] = white[2] * diffuse; // 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]; // set fog color fog_color[0] = base_fog_color[0] * sky_brightness; fog_color[1] = base_fog_color[1] * sky_brightness; fog_color[2] = base_fog_color[2] * sky_brightness; fog_color[3] = base_fog_color[3]; } // calculate fog color adjusted for sunrise/sunset effects void fgLIGHT::UpdateAdjFog( void ) { FGInterface *f; double sun_angle_deg, rotation, param1[3], param2[3]; f = current_aircraft.fdm_state; FG_LOG( FG_EVENT, FG_DEBUG, "Updating adjusted fog parameters." ); // set fog color (we'll try to match the sunset color in the // direction we are looking // first determine the difference between our view angle and local // direction to the sun rotation = -(sun_rotation + FG_PI) - (f->get_Psi() - current_view.get_view_offset()); while ( rotation < 0 ) { rotation += FG_2PI; } while ( rotation > FG_2PI ) { rotation -= FG_2PI; } rotation *= RAD_TO_DEG; // fgPrintf( FG_EVENT, FG_INFO, // " View to sun difference in degrees = %.2f\n", rotation); // next check if we are in a sunset/sunrise situation sun_angle_deg = sun_angle * RAD_TO_DEG; if ( (sun_angle_deg > 80.0) && (sun_angle_deg < 100.0) ) { /* 0.0 - 0.6 */ param1[0] = (10.0 - fabs(90.0 - sun_angle_deg)) / 20.0; param1[1] = (10.0 - fabs(90.0 - sun_angle_deg)) / 40.0; param1[2] = (10.0 - fabs(90.0 - sun_angle_deg)) / 30.0; // param2[2] = -(10.0 - fabs(90.0 - sun_angle)) / 30.0; } else { param1[0] = param1[1] = param1[2] = 0.0; } if ( rotation - 180.0 <= 0.0 ) { param2[0] = param1[0] * (180.0 - rotation) / 180.0; param2[1] = param1[1] * (180.0 - rotation) / 180.0; param2[2] = param1[2] * (180.0 - rotation) / 180.0; // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]); } else { param2[0] = param1[0] * (rotation - 180.0) / 180.0; param2[1] = param1[1] * (rotation - 180.0) / 180.0; param2[2] = param1[2] * (rotation - 180.0) / 180.0; // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]); } adj_fog_color[0] = fog_color[0] + param2[0]; if ( adj_fog_color[0] > 1.0 ) { adj_fog_color[0] = 1.0; } adj_fog_color[1] = fog_color[1] + param2[1]; if ( adj_fog_color[1] > 1.0 ) { adj_fog_color[1] = 1.0; } adj_fog_color[2] = fog_color[2] + param2[2]; if ( adj_fog_color[2] > 1.0 ) { adj_fog_color[2] = 1.0; } adj_fog_color[3] = fog_color[3]; } // Destructor fgLIGHT::~fgLIGHT( void ) { }