#include "sunpos.h"
#include "fg_time.h"
-#include "../constants.h"
-#include "../GLUT/views.h"
+#include "../Include/constants.h"
+#include "../Main/views.h"
#include "../Math/fg_geodesy.h"
#include "../Math/mat3.h"
#include "../Math/polar.h"
+
#undef E
/* update the cur_time_params structure with the current sun position */
-void fgUpdateSunPos(struct fgCartesianPoint scenery_center) {
+void fgUpdateSunPos( void ) {
+ struct fgLIGHT *l;
struct fgTIME *t;
- struct VIEW *v;
+ struct fgVIEW *v;
MAT3vec nup, nsun;
+ /* 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] = {0.70, 0.70, 0.70, 1.0};
double sun_gd_lat, sl_radius, temp;
+ double x_2, x_4, x_8, x_10;
+ double light, ambient, diffuse, sky_brightness;
static int time_warp = 0;
+ l = &cur_light_params;
t = &cur_time_params;
v = ¤t_view;
+ printf(" Updating Sun position\n");
+
time_warp += 0; /* increase this to make the world spin real fast */
- fgSunPosition(t->cur_time + time_warp, &t->sun_lon, &sun_gd_lat);
+ fgSunPosition(t->cur_time + time_warp, &l->sun_lon, &sun_gd_lat);
- fgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &t->sun_gc_lat);
+ fgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &l->sun_gc_lat);
- t->fg_sunpos = fgPolarToCart(t->sun_lon, t->sun_gc_lat, sl_radius);
+ l->fg_sunpos = fgPolarToCart(l->sun_lon, l->sun_gc_lat, sl_radius);
- /* printf("Geodetic lat = %.5f Geocentric lat = %.5f\n", sun_gd_lat,
+ /* printf(" Geodetic lat = %.5f Geocentric lat = %.5f\n", sun_gd_lat,
t->sun_gc_lat); */
- /* the sun position has to be translated just like everything else */
- t->sun_vec[0] = t->fg_sunpos.x - scenery_center.x;
- t->sun_vec[1] = t->fg_sunpos.y - scenery_center.y;
- t->sun_vec[2] = t->fg_sunpos.z - scenery_center.z;
- /* make this a directional light source only */
- t->sun_vec[3] = 0.0;
+ /* FALSE! (?> the sun position has to be translated just like
+ * everything else */
+ /* l->sun_vec_inv[0] = l->fg_sunpos.x - scenery_center.x; */
+ /* l->sun_vec_inv[1] = l->fg_sunpos.y - scenery_center.y; */
+ /* l->sun_vec_inv[2] = l->fg_sunpos.z - scenery_center.z; */
+ /* MAT3_SCALE_VEC(l->sun_vec, l->sun_vec_inv, -1.0); */
+
+ /* I think this will work better for generating the sun light vector */
+ l->sun_vec[0] = l->fg_sunpos.x;
+ l->sun_vec[1] = l->fg_sunpos.y;
+ l->sun_vec[2] = l->fg_sunpos.z;
+ MAT3_NORMALIZE_VEC(l->sun_vec, temp);
+ MAT3_SCALE_VEC(l->sun_vec_inv, l->sun_vec, -1.0);
+
+ /* make these are directional light sources only */
+ l->sun_vec[3] = 0.0;
+ l->sun_vec_inv[3] = 0.0;
- /* calculate thesun's relative angle to local up */
+ printf(" l->sun_vec = %.2f %.2f %.2f\n", l->sun_vec[0], l->sun_vec[1],
+ l->sun_vec[2]);
+
+ /* calculate the sun's relative angle to local up */
MAT3_COPY_VEC(nup, v->local_up);
- nsun[0] = t->fg_sunpos.x;
- nsun[1] = t->fg_sunpos.y;
- nsun[2] = t->fg_sunpos.z;
+ nsun[0] = l->fg_sunpos.x;
+ nsun[1] = l->fg_sunpos.y;
+ nsun[2] = l->fg_sunpos.z;
MAT3_NORMALIZE_VEC(nup, temp);
MAT3_NORMALIZE_VEC(nsun, temp);
- t->sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
- printf("SUN ANGLE relative to current location = %.3f rads.\n",
- t->sun_angle);
+ l->sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
+ printf(" SUN ANGLE relative to current location = %.3f rads.\n",
+ l->sun_angle);
+
+ /* calculate lighting parameters based on sun's relative angle to
+ * local up */
+ /* ya kind'a have to plot this to see how it works */
+
+ /* x = t->sun_angle^8 */
+ x_2 = l->sun_angle * l->sun_angle;
+ x_4 = x_2 * x_2;
+ x_8 = x_4 * x_4;
+ x_10 = x_8 * x_2;
+
+ light = pow(1.1, -x_10 / 30.0);
+ ambient = 0.2 * light;
+ diffuse = 0.9 * light;
+
+ sky_brightness = 0.85 * pow(1.2, -x_8 / 20.0) + 0.15;
+
+ /* sky_brightness = 0.15; */ /* to force a dark sky (for testing) */
+
+ if ( ambient < 0.02 ) { ambient = 0.02; }
+ if ( diffuse < 0.0 ) { diffuse = 0.0; }
+
+ if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
+
+ l->scene_ambient[0] = white[0] * ambient;
+ l->scene_ambient[1] = white[1] * ambient;
+ l->scene_ambient[2] = white[2] * ambient;
+
+ l->scene_diffuse[0] = white[0] * diffuse;
+ l->scene_diffuse[1] = white[1] * diffuse;
+ l->scene_diffuse[2] = white[2] * diffuse;
+
+ /* set fog color */
+ l->fog_color[0] = base_fog_color[0] * (ambient + diffuse);
+ l->fog_color[1] = base_fog_color[1] * (ambient + diffuse);
+ l->fog_color[2] = base_fog_color[2] * (ambient + diffuse);
+ l->fog_color[3] = base_fog_color[3];
+
+ /* set sky color */
+ l->sky_color[0] = base_sky_color[0] * sky_brightness;
+ l->sky_color[1] = base_sky_color[1] * sky_brightness;
+ l->sky_color[2] = base_sky_color[2] * sky_brightness;
+ l->sky_color[3] = base_sky_color[3];
}
/* $Log$
-/* Revision 1.10 1997/09/13 02:00:09 curt
-/* Mostly working on stars and generating sidereal time for accurate star
-/* placement.
+/* Revision 1.22 1998/01/19 18:40:40 curt
+/* Tons of little changes to clean up the code and to remove fatal errors
+/* when building with the c++ compiler.
/*
+ * Revision 1.21 1997/12/30 23:10:19 curt
+ * Calculate lighting parameters here.
+ *
+ * Revision 1.20 1997/12/30 22:22:43 curt
+ * Further integration of event manager.
+ *
+ * Revision 1.19 1997/12/30 20:47:59 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.18 1997/12/23 04:58:40 curt
+ * Tweaked the sky coloring a bit to build in structures to allow finer rgb
+ * control.
+ *
+ * Revision 1.17 1997/12/15 23:55:08 curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.16 1997/12/11 04:43:57 curt
+ * Fixed sun vector and lighting problems. I thing the moon is now lit
+ * correctly.
+ *
+ * Revision 1.15 1997/12/10 22:37:55 curt
+ * Prepended "fg" on the name of all global structures that didn't have it yet.
+ * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
+ *
+ * Revision 1.14 1997/12/09 04:25:39 curt
+ * Working on adding a global lighting params structure.
+ *
+ * Revision 1.13 1997/11/25 19:25:42 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.12 1997/11/15 18:15:39 curt
+ * Reverse direction of sun vector, so object normals can be more normal.
+ *
+ * Revision 1.11 1997/10/28 21:07:21 curt
+ * Changed GLUT/ -> Main/
+ *
+ * Revision 1.10 1997/09/13 02:00:09 curt
+ * Mostly working on stars and generating sidereal time for accurate star
+ * placement.
+ *
* Revision 1.9 1997/09/05 14:17:31 curt
* More tweaking with stars.
*