173 lines
5.1 KiB
C++
173 lines
5.1 KiB
C++
//
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// light.hxx -- lighting routines
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//
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// Written by Curtis Olson, started April 1998.
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//
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// Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of the
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// License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful, but
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// WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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//
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// $Id$
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#ifdef HAVE_WINDOWS_H
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# include <windows.h>
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#endif
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#include <GL/glut.h>
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#include <XGL/xgl.h>
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#include <string.h>
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#include <Debug/fg_debug.h>
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#include <Include/fg_constants.h>
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#include <Include/general.h>
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#include <Main/views.hxx>
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#include <Math/fg_geodesy.h>
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#include <Math/interpolater.hxx>
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#include <Math/mat3.h>
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#include <Math/polar.h>
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#include "fg_time.hxx"
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#include "light.hxx"
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#include "sunpos.hxx"
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fgLIGHT cur_light_params;
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static fgINTERPTABLE *ambient_tbl;
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static fgINTERPTABLE *diffuse_tbl;
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static fgINTERPTABLE *sky_tbl;
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// initialize lighting tables
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void fgLightInit( void ) {
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fgGENERAL *g;
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char path[256];
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fgPrintf( FG_EVENT, FG_INFO,
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"Initializing Lighting interpolation tables.\n" );
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g = &general;
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// build the path name to the ambient lookup table
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path[0] = '\0';
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strcat(path, g->root_dir);
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strcat(path, "/Scenery/");
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strcat(path, "Ambient.table");
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// initialize ambient table
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ambient_tbl = new fgINTERPTABLE(path);
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// build the path name to the diffuse lookup table
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path[0] = '\0';
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strcat(path, g->root_dir);
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strcat(path, "/Scenery/");
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strcat(path, "Diffuse.table");
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// initialize diffuse table
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diffuse_tbl = new fgINTERPTABLE(path);
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// build the path name to the sky lookup table
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path[0] = '\0';
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strcat(path, g->root_dir);
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strcat(path, "/Scenery/");
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strcat(path, "Sky.table");
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// initialize sky table
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sky_tbl = new fgINTERPTABLE(path);
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}
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// update lighting parameters based on current sun position
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void fgLightUpdate( void ) {
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fgLIGHT *l;
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struct fgTIME *t;
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struct fgVIEW *v;
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/* if the 4th field is 0.0, this specifies a direction ... */
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GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
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/* base sky color */
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GLfloat base_sky_color[4] = {0.60, 0.60, 0.90, 1.0};
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/* base fog color */
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GLfloat base_fog_color[4] = {1.00, 1.00, 1.00, 1.0};
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double deg, ambient, diffuse, sky_brightness;
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l = &cur_light_params;
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t = &cur_time_params;
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v = ¤t_view;
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fgPrintf( FG_EVENT, FG_INFO, "Updating light parameters.\n" );
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/* calculate lighting parameters based on sun's relative angle to
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* local up */
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deg = l->sun_angle * 180.0 / FG_PI;
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fgPrintf( FG_EVENT, FG_INFO, " Sun angle = %.2f.\n", deg );
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ambient = ambient_tbl->interpolate( deg );
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diffuse = diffuse_tbl->interpolate( deg );
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sky_brightness = sky_tbl->interpolate( deg );
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fgPrintf( FG_EVENT, FG_INFO,
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" ambient = %.2f diffuse = %.2f sky = %.2f\n",
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ambient, diffuse, sky_brightness );
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// sky_brightness = 0.15; // used to force a dark sky (when testing)
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// if ( ambient < 0.02 ) { ambient = 0.02; }
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// if ( diffuse < 0.0 ) { diffuse = 0.0; }
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// if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
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l->scene_ambient[0] = white[0] * ambient;
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l->scene_ambient[1] = white[1] * ambient;
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l->scene_ambient[2] = white[2] * ambient;
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l->scene_diffuse[0] = white[0] * diffuse;
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l->scene_diffuse[1] = white[1] * diffuse;
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l->scene_diffuse[2] = white[2] * diffuse;
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/* set fog color */
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// l->fog_color[0] = base_fog_color[0] * (ambient + diffuse);
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// l->fog_color[1] = base_fog_color[1] * (ambient + diffuse);
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// l->fog_color[2] = base_fog_color[2] * (ambient + diffuse);
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// l->fog_color[3] = base_fog_color[3];
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l->fog_color[0] = base_fog_color[0] * sky_brightness;
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l->fog_color[1] = base_fog_color[1] * sky_brightness;
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l->fog_color[2] = base_fog_color[2] * sky_brightness;
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l->fog_color[3] = base_fog_color[3];
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/* set sky color */
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l->sky_color[0] = base_sky_color[0] * sky_brightness;
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l->sky_color[1] = base_sky_color[1] * sky_brightness;
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l->sky_color[2] = base_sky_color[2] * sky_brightness;
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l->sky_color[3] = base_sky_color[3];
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}
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// $Log$
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// Revision 1.3 1998/04/26 05:10:04 curt
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// "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
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//
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// Revision 1.2 1998/04/24 00:52:30 curt
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// Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
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// Fog color fixes.
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// Separated out lighting calcs into their own file.
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//
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// Revision 1.1 1998/04/22 13:24:06 curt
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// C++ - ifiing the code a bit.
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// Starting to reorginize some of the lighting calcs to use a table lookup.
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//
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//
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