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flightgear/Scenery/tilemgr.cxx
curt 7f1d04962e Beginning to add support for view frustum culling. 
Added some temporary code to calculate bouding radius, until the
  scenery generation tools and scenery can be updated.
1998-05-16 13:09:57 +00:00

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/*
* tilemgr.cxx -- routines to handle dynamic management of scenery tiles
*
* Written by Curtis Olson, started January 1998.
*
* 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)
**************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#include <GL/glut.h>
#include <XGL/xgl.h>
#include <Scenery/obj.hxx>
#include <Scenery/scenery.hxx>
#include <Scenery/tilecache.hxx>
#include <Aircraft/aircraft.h>
#include <Bucket/bucketutils.h>
#include <Debug/fg_debug.h>
#include <Include/fg_constants.h>
#include <Include/fg_types.h>
#include <Main/options.hxx>
#include <Main/views.hxx>
#include <Math/mat3.h>
#define FG_LOCAL_X_Y 81 /* max(o->tile_diameter) ** 2 */
/* closest (potentially viewable) tiles, centered on current tile.
* This is an array of pointers to cache indexes. */
int tiles[FG_LOCAL_X_Y];
/* Initialize the Tile Manager subsystem */
int fgTileMgrInit( void ) {
fgPrintf( FG_TERRAIN, FG_INFO, "Initializing Tile Manager subsystem.\n");
return 1;
}
/* load a tile */
void fgTileMgrLoadTile( struct fgBUCKET *p, int *index) {
fgPrintf( FG_TERRAIN, FG_DEBUG, "Updating for bucket %d %d %d %d\n",
p->lon, p->lat, p->x, p->y);
/* if not in cache, load tile into the next available slot */
if ( (*index = fgTileCacheExists(p)) < 0 ) {
*index = fgTileCacheNextAvail();
fgTileCacheEntryFillIn(*index, p);
}
fgPrintf( FG_TERRAIN, FG_DEBUG, "Selected cache index of %d\n", *index);
}
/* given the current lon/lat, fill in the array of local chunks. If
* the chunk isn't already in the cache, then read it from disk. */
int fgTileMgrUpdate( void ) {
fgFLIGHT *f;
fgOPTIONS *o;
struct fgBUCKET p1, p2;
static struct fgBUCKET p_last = {-1000, 0, 0, 0};
int i, j, dw, dh;
f = current_aircraft.flight;
o = &current_options;
fgBucketFind(FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG, &p1);
dw = o->tile_diameter / 2;
dh = o->tile_diameter / 2;
if ( (p1.lon == p_last.lon) && (p1.lat == p_last.lat) &&
(p1.x == p_last.x) && (p1.y == p_last.y) ) {
/* same bucket as last time */
fgPrintf( FG_TERRAIN, FG_DEBUG, "Same bucket as last time\n");
} else if ( p_last.lon == -1000 ) {
/* First time through, initialize the system and load all
* relavant tiles */
fgPrintf( FG_TERRAIN, FG_INFO, " First time through ... ");
fgPrintf( FG_TERRAIN, FG_INFO, " Updating Tile list for %d,%d %d,%d\n",
p1.lon, p1.lat, p1.x, p1.y);
fgPrintf( FG_TERRAIN, FG_INFO, " Loading %d tiles\n",
o->tile_diameter * o->tile_diameter);
/* wipe tile cache */
fgTileCacheInit();
/* build the local area list and update cache */
for ( j = 0; j < o->tile_diameter; j++ ) {
for ( i = 0; i < o->tile_diameter; i++ ) {
fgBucketOffset(&p1, &p2, i - dw, j - dh);
fgTileMgrLoadTile(&p2, &tiles[(j*o->tile_diameter) + i]);
}
}
} else {
/* We've moved to a new bucket, we need to scroll our
* structures, and load in the new tiles */
/* CURRENTLY THIS ASSUMES WE CAN ONLY MOVE TO ADJACENT TILES.
AT ULTRA HIGH SPEEDS THIS ASSUMPTION MAY NOT BE VALID IF
THE AIRCRAFT CAN SKIP A TILE IN A SINGLE ITERATION. */
fgPrintf( FG_TERRAIN, FG_INFO, "Updating Tile list for %d,%d %d,%d\n",
p1.lon, p1.lat, p1.x, p1.y);
if ( (p1.lon > p_last.lon) ||
( (p1.lon == p_last.lon) && (p1.x > p_last.x) ) ) {
fgPrintf( FG_TERRAIN, FG_INFO, " Loading %d tiles\n",
o->tile_diameter);
for ( j = 0; j < o->tile_diameter; j++ ) {
/* scrolling East */
for ( i = 0; i < o->tile_diameter - 1; i++ ) {
tiles[(j*o->tile_diameter) + i] = tiles[(j*o->tile_diameter) + i + 1];
}
/* load in new column */
fgBucketOffset(&p_last, &p2, dw + 1, j - dh);
fgTileMgrLoadTile(&p2, &tiles[(j*o->tile_diameter) + o->tile_diameter - 1]);
}
} else if ( (p1.lon < p_last.lon) ||
( (p1.lon == p_last.lon) && (p1.x < p_last.x) ) ) {
fgPrintf( FG_TERRAIN, FG_INFO, " Loading %d tiles\n",
o->tile_diameter);
for ( j = 0; j < o->tile_diameter; j++ ) {
/* scrolling West */
for ( i = o->tile_diameter - 1; i > 0; i-- ) {
tiles[(j*o->tile_diameter) + i] = tiles[(j*o->tile_diameter) + i - 1];
}
/* load in new column */
fgBucketOffset(&p_last, &p2, -dw - 1, j - dh);
fgTileMgrLoadTile(&p2, &tiles[(j*o->tile_diameter) + 0]);
}
}
if ( (p1.lat > p_last.lat) ||
( (p1.lat == p_last.lat) && (p1.y > p_last.y) ) ) {
fgPrintf( FG_TERRAIN, FG_INFO, " Loading %d tiles\n",
o->tile_diameter);
for ( i = 0; i < o->tile_diameter; i++ ) {
/* scrolling North */
for ( j = 0; j < o->tile_diameter - 1; j++ ) {
tiles[(j * o->tile_diameter) + i] =
tiles[((j+1) * o->tile_diameter) + i];
}
/* load in new column */
fgBucketOffset(&p_last, &p2, i - dw, dh + 1);
fgTileMgrLoadTile(&p2, &tiles[((o->tile_diameter-1)*o->tile_diameter) + i]);
}
} else if ( (p1.lat < p_last.lat) ||
( (p1.lat == p_last.lat) && (p1.y < p_last.y) ) ) {
fgPrintf( FG_TERRAIN, FG_INFO, " Loading %d tiles\n",
o->tile_diameter);
for ( i = 0; i < o->tile_diameter; i++ ) {
/* scrolling South */
for ( j = o->tile_diameter - 1; j > 0; j-- ) {
tiles[(j * o->tile_diameter) + i] =
tiles[((j-1) * o->tile_diameter) + i];
}
/* load in new column */
fgBucketOffset(&p_last, &p2, i - dw, -dh - 1);
fgTileMgrLoadTile(&p2, &tiles[0 + i]);
}
}
}
p_last.lon = p1.lon;
p_last.lat = p1.lat;
p_last.x = p1.x;
p_last.y = p1.y;
return 1;
}
// Calculate if point/radius is inside view frustum
//
static int viewable( fgCartesianPoint3d *cp, double radius ) {
fgVIEW *v;
MAT3hvec world, eye;
int viewable = 1; // start by assuming it's viewable
v = &current_view;
MAT3_SET_HVEC(world, cp->x, cp->y, cp->z, 1.0);
MAT3mult_vec(eye, world, v->WORLD_TO_EYE);
// printf( "\nworld -> eye = %.2f %.2f %.2f radius = %.2f\n",
// eye[0], eye[1], eye[2], radius);
if ( eye[2] - radius > 0.0 ) {
// Check near clip plane
viewable = 0;
} else if ( eye[1] < -(v->slope_x) * (eye[0] + radius) ) {
// Check left edge
// y = m * (x - x0) = equation of a line intercepting X axis at x0
printf( "eye[1] = %.2f slope_x = %.2f radius = %.2f\n",
eye[1], v->slope_x, radius);
viewable = 0;
}
return(viewable);
}
/* Render the local tiles */
void fgTileMgrRender( void ) {
fgFLIGHT *f;
fgOPTIONS *o;
struct fgBUCKET p;
fgCartesianPoint3d local_ref, offset;
GLint display_list;
double radius;
int i;
int index;
int culled = 0;
int drawn = 0;
f = current_aircraft.flight;
o = &current_options;
/* Find current translation offset */
fgBucketFind(FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG, &p);
index = fgTileCacheExists(&p);
fgTileCacheEntryInfo(index, &display_list, &scenery.next_center, &radius );
fgPrintf( FG_TERRAIN, FG_DEBUG,
"Pos = (%.2f, %.2f) Current bucket = %d %d %d %d Index = %ld\n",
FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG,
p.lon, p.lat, p.x, p.y, fgBucketGenIndex(&p) );
for ( i = 0; i < (o->tile_diameter * o->tile_diameter); i++ ) {
index = tiles[i];
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "Index = %d\n", index); */
fgTileCacheEntryInfo(index, &display_list, &local_ref, &radius );
if ( display_list >= 0 ) {
offset.x = local_ref.x - scenery.center.x;
offset.y = local_ref.y - scenery.center.y;
offset.z = local_ref.z - scenery.center.z;
if ( viewable(&offset, radius) ) {
drawn++;
xglPushMatrix();
xglTranslatef(offset.x, offset.y, offset.z);
xglCallList(display_list);
xglPopMatrix();
} else {
culled++;
}
}
}
printf("drawn = %d culled = %d saved = %.2f\n", drawn, culled,
(double)culled / (double)(drawn + culled));
}
/* $Log$
/* Revision 1.9 1998/05/16 13:09:58 curt
/* Beginning to add support for view frustum culling.
/* Added some temporary code to calculate bouding radius, until the
/* scenery generation tools and scenery can be updated.
/*
* Revision 1.8 1998/05/07 23:15:21 curt
* Fixed a glTexImage2D() usage bug where width and height were mis-swapped.
* Added support for --tile-radius=n option.
*
* Revision 1.7 1998/05/06 03:16:42 curt
* Added an option to control square tile radius.
*
* Revision 1.6 1998/05/02 01:52:18 curt
* Playing around with texture coordinates.
*
* Revision 1.5 1998/04/30 12:35:32 curt
* Added a command line rendering option specify smooth/flat shading.
*
* Revision 1.4 1998/04/27 03:30:14 curt
* Minor transformation adjustments to try to keep scenery tiles closer to
* (0, 0, 0) GLfloats run out of precision at the distances we need to model
* the earth, but we can do a bunch of pre-transformations using double math
* and then cast to GLfloat once everything is close in where we have less
* precision problems.
*
* Revision 1.3 1998/04/25 22:06:32 curt
* Edited cvs log messages in source files ... bad bad bad!
*
* Revision 1.2 1998/04/24 00:51:09 curt
* Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
* Tweaked the scenery file extentions to be "file.obj" (uncompressed)
* or "file.obz" (compressed.)
*
* Revision 1.1 1998/04/22 13:22:48 curt
* C++ - ifing the code a bit.
*
* Revision 1.25 1998/04/18 04:14:07 curt
* Moved fg_debug.c to it's own library.
*
* Revision 1.24 1998/04/14 02:23:18 curt
* Code reorganizations. Added a Lib/ directory for more general libraries.
*
* Revision 1.23 1998/04/08 23:30:08 curt
* Adopted Gnu automake/autoconf system.
*
* Revision 1.22 1998/04/03 22:11:38 curt
* Converting to Gnu autoconf system.
*
* Revision 1.21 1998/03/23 21:23:05 curt
* Debugging output tweaks.
*
* Revision 1.20 1998/03/14 00:30:51 curt
* Beginning initial terrain texturing experiments.
*
* Revision 1.19 1998/02/20 00:16:25 curt
* Thursday's tweaks.
*
* Revision 1.18 1998/02/19 13:05:54 curt
* Incorporated some HUD tweaks from Michelle America.
* Tweaked the sky's sunset/rise colors.
* Other misc. tweaks.
*
* Revision 1.17 1998/02/16 13:39:46 curt
* Miscellaneous weekend tweaks. Fixed? a cache problem that caused whole
* tiles to occasionally be missing.
*
* Revision 1.16 1998/02/12 21:59:53 curt
* Incorporated code changes contributed by Charlie Hotchkiss
* <chotchkiss@namg.us.anritsu.com>
*
* Revision 1.14 1998/02/09 21:30:19 curt
* Fixed a nagging problem with terrain tiles not "quite" matching up perfectly.
*
* Revision 1.13 1998/02/07 15:29:46 curt
* Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
* <chotchkiss@namg.us.anritsu.com>
*
* Revision 1.12 1998/02/01 03:39:55 curt
* Minor tweaks.
*
* Revision 1.11 1998/01/31 00:43:27 curt
* Added MetroWorks patches from Carmen Volpe.
*
* Revision 1.10 1998/01/29 00:51:40 curt
* First pass at tile cache, dynamic tile loading and tile unloading now works.
*
* Revision 1.9 1998/01/27 03:26:44 curt
* Playing with new fgPrintf command.
*
* Revision 1.8 1998/01/27 00:48:04 curt
* Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
* system and commandline/config file processing code.
*
* Revision 1.7 1998/01/26 15:55:25 curt
* Progressing on building dynamic scenery system.
*
* Revision 1.6 1998/01/24 00:03:30 curt
* Initial revision.
*
* Revision 1.5 1998/01/19 19:27:18 curt
* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
* This should simplify things tremendously.
*
* Revision 1.4 1998/01/19 18:40:38 curt
* Tons of little changes to clean up the code and to remove fatal errors
* when building with the c++ compiler.
*
* Revision 1.3 1998/01/13 00:23:11 curt
* Initial changes to support loading and management of scenery tiles. Note,
* there's still a fair amount of work left to be done.
*
* Revision 1.2 1998/01/08 02:22:27 curt
* Continue working on basic features.
*
* Revision 1.1 1998/01/07 23:50:51 curt
* "area" renamed to "tile"
*
* Revision 1.2 1998/01/07 03:29:29 curt
* Given an arbitrary lat/lon, we can now:
* generate a unique index for the chunk containing the lat/lon
* generate a path name to the chunk file
* build a list of the indexes of all the nearby areas.
*
* Revision 1.1 1998/01/07 02:05:48 curt
* Initial revision.
* */
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