/************************************************************************** * GLmain.c -- top level sim routines * * Written by Curtis Olson for OpenGL, started May 1997. * * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com * * 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. * * $Id$ * (Log is kept at end of this file) **************************************************************************/ #include #include #include #include /* for timer routines */ #include /* for timer routines */ #ifdef GLUT #include #include "GLUTkey.h" #elif MESA_TK /* assumes -I/usr/include/mesa in compile command */ #include "gltk.h" #include "GLTKkey.h" #endif #include "../aircraft/aircraft.h" #include "../scenery/scenery.h" /* This is a record containing all the info for the aircraft currently being operated */ struct aircraft_params current_aircraft; /* view parameters */ static GLfloat win_ratio = 1.0; /* temporary hack */ extern struct mesh *mesh_ptr; /* Function prototypes */ GLint fgSceneryCompile(); static void fgSceneryDraw(); /* pointer to terrain mesh structure */ static GLint mesh; /* Another hack */ double fogDensity = 2000.0; /* Another hack */ #define DEFAULT_MODEL_HZ 120 double Simtime; int Overrun; int model_dt; /************************************************************************** * fgInitVisuals() -- Initialize various GL/view parameters **************************************************************************/ static void fgInitVisuals() { /* if the 4th field is 0.0, this specifies a direction ... */ static GLfloat sun_vec[4] = {3.0, 1.0, 3.0, 0.0 }; static GLfloat color[4] = { 0.3, 0.7, 0.2, 1.0 }; static GLfloat fogColor[4] = {0.65, 0.65, 0.85, 1.0}; glEnable( GL_DEPTH_TEST ); glFrontFace(GL_CW); glEnable( GL_CULL_FACE ); /* If enabled, normal vectors specified with glNormal are scaled to unit length after transformation. See glNormal. */ glEnable( GL_NORMALIZE ); glLightfv( GL_LIGHT0, GL_POSITION, sun_vec ); glEnable( GL_LIGHTING ); glEnable( GL_LIGHT0 ); glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, color ); glShadeModel( GL_FLAT ); /* glShadeModel( GL_SMOOTH ); */ glEnable( GL_FOG ); glFogi (GL_FOG_MODE, GL_LINEAR); /* glFogf (GL_FOG_START, 1.0); */ glFogf (GL_FOG_END, fogDensity); glFogfv (GL_FOG_COLOR, fogColor); /* glFogf (GL_FOG_DENSITY, fogDensity); */ /* glHint (GL_FOG_HINT, GL_FASTEST); */ glClearColor(0.6, 0.6, 0.9, 1.0); } /************************************************************************** * Update the view volume, position, and orientation **************************************************************************/ static void fgUpdateViewParams() { struct flight_params *f; f = ¤t_aircraft.flight; /* Tell GL we are about to modify the projection parameters */ glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45.0, 1.0/win_ratio, 1.0, 6000.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); gluLookAt(f->pos_x, f->pos_y, f->pos_z, f->pos_x + cos(f->Psi), f->pos_y + sin(f->Psi), f->pos_z, 0.0, 0.0, 1.0); } /************************************************************************** * Update all Visuals (redraws anything graphics related) **************************************************************************/ static void fgUpdateVisuals( void ) { /* update view volume parameters */ fgUpdateViewParams(); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); /* Tell GL we are switching to model view parameters */ glMatrixMode(GL_MODELVIEW); /* glLoadIdentity(); */ /* draw terrain mesh */ fgSceneryDraw(); #ifdef GLUT glutSwapBuffers(); #elif MESA_TK tkSwapBuffers(); #endif } /************************************************************************** * Timer management routines **************************************************************************/ static struct itimerval t, ot; /* This routine catches the SIGALRM */ void fgTimerCatch() { static double lastSimtime = -99.9; /* printf("In fgTimerCatch()\n"); */ Overrun = (lastSimtime == Simtime); /* if ( Overrun ) { printf("OVERRUN!!!\n"); } */ lastSimtime = Simtime; signal(SIGALRM, fgTimerCatch); } /* this routine initializes the interval timer to generate a SIGALRM after * the specified interval (dt) */ void fgTimerInit(float dt) { int terr; int isec; float usec; isec = (int) dt; usec = 1000000* (dt - (float) isec); t.it_interval.tv_sec = isec; t.it_interval.tv_usec = usec; t.it_value.tv_sec = isec; t.it_value.tv_usec = usec; /* printf("fgTimerInit() called\n"); */ fgTimerCatch(); /* set up for SIGALRM signal catch */ terr = setitimer( ITIMER_REAL, &t, &ot ); if (terr) perror("Error returned from setitimer"); } /************************************************************************** * Scenery management routines **************************************************************************/ static void fgSceneryInit() { /* make terrain mesh */ mesh = fgSceneryCompile(); } /* create the terrain mesh */ GLint fgSceneryCompile() { GLint mesh; mesh = mesh2GL(mesh_ptr); return(mesh); } /* draw the terrain mesh */ static void fgSceneryDraw() { glCallList(mesh); } /* What should we do when we have nothing else to do? How about get * ready for the next move?*/ static void fgMainLoop( void ) { slew_update(); aircraft_debug(1); fgUpdateVisuals(); } /************************************************************************** * Handle new window size or exposure **************************************************************************/ static void fgReshape( int width, int height ) { /* Do this so we can call fgReshape(0,0) ourselves without having to know * what the values of width & height are. */ if ( (height > 0) && (width > 0) ) { win_ratio = (GLfloat) height / (GLfloat) width; } /* Inform gl of our view window size */ glViewport(0, 0, (GLint)width, (GLint)height); fgUpdateViewParams(); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); } /************************************************************************** * Main ... **************************************************************************/ int main( int argc, char *argv[] ) { /* parse the scenery file */ parse_scenery(argv[1]); #ifdef GLUT /* initialize GLUT */ glutInit(&argc, argv); /* Define Display Parameters */ glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE ); /* Define initial window size */ glutInitWindowSize(640, 400); /* Initialize the main window */ glutCreateWindow("Terrain Demo"); #elif MESA_TK /* Define initial window size */ tkInitPosition(0, 0, 640, 400); /* Define Display Parameters */ tkInitDisplayMode( TK_RGB | TK_DEPTH | TK_DOUBLE | TK_DIRECT ); /* Initialize the main window */ if (tkInitWindow("Terrain Demo") == GL_FALSE) { tkQuit(); } #endif /* setup view parameters, only makes GL calls */ fgInitVisuals(); /* Set initial position and slew parameters */ /* slew_init(-398391.3, 120070.4, 244, 3.1415); */ /* GLOBE Airport */ /* slew_init(-335340,162540, 15, 4.38); */ slew_init(-398673.28,120625.64, 53, 4.38); /* build all objects */ fgSceneryInit(); /* initialize timer */ fgTimerInit( 1.0 / DEFAULT_MODEL_HZ ); #ifdef GLUT /* call fgReshape() on window resizes */ glutReshapeFunc( fgReshape ); /* call key() on keyboard event */ glutKeyboardFunc( GLUTkey ); glutSpecialFunc( GLUTkey ); /* call fgMainLoop() whenever there is nothing else to do */ glutIdleFunc( fgMainLoop ); /* draw the scene */ glutDisplayFunc( fgUpdateVisuals ); /* pass control off to the GLUT event handler */ glutMainLoop(); #elif MESA_TK /* call fgReshape() on expose events */ tkExposeFunc( fgReshape ); /* call fgReshape() on window resizes */ tkReshapeFunc( fgReshape ); /* call key() on keyboard event */ tkKeyDownFunc( GLTKkey ); /* call fgMainLoop() whenever there is nothing else to do */ tkIdleFunc( fgMainLoop ); /* draw the scene */ tkDisplayFunc( fgUpdateVisuals ); /* pass control off to the tk event handler */ tkExec(); #endif return(0); } /* $Log$ /* Revision 1.4 1997/05/27 17:44:31 curt /* Renamed & rearranged variables and routines. Added some initial simple /* timer/alarm routines so the flight model can be updated on a regular interval. /* * Revision 1.3 1997/05/23 15:40:25 curt * Added GNU copyright headers. * Fog now works! * * Revision 1.2 1997/05/23 00:35:12 curt * Trying to get fog to work ... * * Revision 1.1 1997/05/21 15:57:51 curt * Renamed due to added GLUT support. * * Revision 1.3 1997/05/19 18:22:42 curt * Parameter tweaking ... starting to stub in fog support. * * Revision 1.2 1997/05/17 00:17:34 curt * Trying to stub in support for standard OpenGL. * * Revision 1.1 1997/05/16 16:05:52 curt * Initial revision. * */