// $Id$
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
#include <stdio.h>
#include <iostream>
+#include <plib/sg.h>
#include <plib/ssg.h>
-#include <simgear/constants.h>
-
#include "stars.hxx"
+#ifdef _MSC_VER
+FG_USING_STD(cout);
+FG_USING_STD(endl);
+#endif
+
// Set up star rendering call backs
static int sgStarPreDraw( ssgEntity *e ) {
state->disable( GL_TEXTURE_2D );
state->enable( GL_COLOR_MATERIAL );
state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
+ state->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
+ state->setMaterial( GL_SPECULAR, 0, 0, 0, 1 );
state->enable( GL_BLEND );
state->disable( GL_ALPHA_TEST );
// 90 degrees = sun rise/set
// 180 degrees = darkest midnight
bool SGStars::repaint( double sun_angle, int num, sgdVec3 *star_data ) {
- // TEST return true;
-
+ // double min = 100;
+ // double max = -100;
+ double mag, nmag, alpha, factor, cutoff;
float *color;
+
+ // determine which star structure to draw
+ if ( sun_angle > (2 * SGD_PI + 10.0 * SGD_DEGREES_TO_RADIANS ) ) {
+ // deep night
+ factor = 1.0;
+ cutoff = 4.5;
+ } else if ( sun_angle > (2 * SGD_PI + 8.8 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 1.0;
+ cutoff = 3.8;
+ } else if ( sun_angle > (2 * SGD_PI + 7.5 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 0.95;
+ cutoff = 3.1;
+ } else if ( sun_angle > (2 * SGD_PI + 7.0 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 0.9;
+ cutoff = 2.4;
+ } else if ( sun_angle > (2 * SGD_PI + 6.5 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 0.85;
+ cutoff = 1.8;
+ } else if ( sun_angle > (2 * SGD_PI + 6.0 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 0.8;
+ cutoff = 1.2;
+ } else if ( sun_angle > (2 * SGD_PI + 5.5 * SGD_DEGREES_TO_RADIANS ) ) {
+ factor = 0.75;
+ cutoff = 0.6;
+ } else {
+ // early dusk or late dawn
+ factor = 0.7;
+ cutoff = 0.0;
+ }
+
for ( int i = 0; i < num; ++i ) {
+ // if ( star_data[i][2] < min ) { min = star_data[i][2]; }
+ // if ( star_data[i][2] > max ) { max = star_data[i][2]; }
+
+ // magnitude ranges from -1 (bright) to 4 (dim). The range of
+ // star and planet magnitudes can actually go outside of this,
+ // but for our purpose, if it is brighter that -1, we'll color
+ // it full white/alpha anyway and 4 is a convenient cutoff
+ // point which keeps the number of stars drawn at about 500.
+
// color (magnitude)
- double magnitude = (0.0 - star_data[i][2]) / 5.0 + 1.0;
- magnitude = magnitude * 0.7 + (3 * 0.1);
- if (magnitude > 1.0) magnitude = 1.0;
- if (magnitude < 0.0) magnitude = 0.0;
+ mag = star_data[i][2];
+ if ( mag < cutoff ) {
+ nmag = ( 4.5 - mag ) / 5.5; // translate to 0 ... 1.0 scale
+ // alpha = nmag * 0.7 + 0.3; // translate to a 0.3 ... 1.0 scale
+ alpha = nmag * 0.85 + 0.15; // translate to a 0.15 ... 1.0 scale
+ alpha *= factor; // dim when the sun is brighter
+ } else {
+ alpha = 0.0;
+ }
+
+ if (alpha > 1.0) { alpha = 1.0; }
+ if (alpha < 0.0) { alpha = 0.0; }
color = cl->get( i );
- sgSetVec4( color, 1.0, 1.0, 1.0, magnitude );
- // sgSetVec4( color, 1, 1, 1, 1.0 );
- // cout << "color[" << i << "] = " << magnitude << endl;
+ sgSetVec4( color, 1.0, 1.0, 1.0, alpha );
+ // cout << "alpha[" << i << "] = " << alpha << endl;
}
+ // cout << "min = " << min << " max = " << max << " count = " << num
+ // << endl;
+
return true;
}