FGFS-4.1/simgear
4
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update star repainting to fade as the day get's brighter, also reworked

Browse Source 
coloring just a bit.
This commit is contained in:
curt 2000-03-16 22:02:47 +00:00
parent 1984ae1583
commit acc2075986
1 changed files with 58 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
simgear/sky/stars.cxx
View File

@ -131,22 +131,71 @@ ssgBranch * SGStars::build( int num, sgdVec3 *star_data, double star_dist ) {
// 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 > (FG_PI_2 + 10.0 * DEG_TO_RAD ) ) {
// deep night
factor = 1.0;
cutoff = 4.2;
} else if ( sun_angle > (FG_PI_2 + 8.8 * DEG_TO_RAD ) ) {
factor = 1.0;
cutoff = 3.6;
} else if ( sun_angle > (FG_PI_2 + 7.5 * DEG_TO_RAD ) ) {
factor = 0.95;
cutoff = 3.0;
} else if ( sun_angle > (FG_PI_2 + 7.0 * DEG_TO_RAD ) ) {
factor = 0.9;
cutoff = 2.4;
} else if ( sun_angle > (FG_PI_2 + 6.5 * DEG_TO_RAD ) ) {
factor = 0.85;
cutoff = 1.8;
} else if ( sun_angle > (FG_PI_2 + 6.0 * DEG_TO_RAD ) ) {
factor = 0.8;
cutoff = 1.2;
} else if ( sun_angle > (FG_PI_2 + 5.5 * DEG_TO_RAD ) ) {
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 - mag ) / 5.0; // translate to 0 ... 1.0 scale
alpha = nmag * 0.7 + 0.3; // translate to a 0.3 ... 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;
}