Add rgb565 blackbody-color encoding from Mitchell Charity's code.

src/kiraserver.cc

@@ -9,6 +9,9 @@
 
 /* 
  * $Log$
+ * Revision 1.8  2002/04/23 03:21:22  slevy
+ * Add rgb565 blackbody-color encoding from Mitchell Charity's code.
+ *
  * Revision 1.7  2002/04/22 23:16:50  slevy
  * Ignore SIGPIPEs in case the caller disconnects early.
  * Accept T=<scalefactor> as well as T=<16 numbers>.
@@ -906,6 +909,25 @@ void starswap(db_star *st) {
 #define  starswap(x)  /*nothing*/
 #endif /*!WORDS_BIGENDIAN*/
 
+static struct logTmap {
+	float logT;
+	unsigned short rgb565;
+} tmap[] = {
+//  Adapted from Mitchell Charity's web page on black body RGB colors,
+//   http://www.vendian.org/mncharity/dir3/blackbody/
+  3.000, 0xf9c0,  3.079, 0xfa80,  3.204, 0xfb80,  3.301, 0xfc42,
+  3.380, 0xfce7,  3.477, 0xfdad,  3.556, 0xfe31,  3.643, 0xfed6,
+  3.716, 0xff5a,  3.792, 0xffbe,  3.869, 0xef7f,  3.944, 0xdf1f,
+  4.017, 0xcedf,  4.093, 0xbe9f,  4.164, 0xb67f,  4.236, 0xae5f,
+  4.310, 0xae3f,  4.380, 0xa61f,  4.450, 0xa5ff,
+};
+
+static unsigned short logT2rgb565(float logT) {
+    int i;
+    for(i = 0; i < COUNT(tmap)-1 && logT > tmap[i].logT; i++)
+	;
+    return tmap[i].rgb565;
+}
 
 int serveonce(char *req, FILE *outf)
 {
@@ -988,7 +1010,12 @@ int serveonce(char *req, FILE *outf)
 	    star.y = p.x[1];
 	    star.z = p.x[2];
 	    star.magnitude = curstate.mag0 - .921 * logf( sp->val[SPECK_LUM] );
-	    star.color = (unsigned short) (curstate.colorscale * sp->val[SPECK_TLOG]);
+	    if(curstate.colorscale >= 0) {
+		star.color = (unsigned short) (curstate.colorscale * sp->val[SPECK_TLOG]);
+	    } else {
+		/* packed rgb565 */
+		star.color = logT2rgb565( sp->val[SPECK_TLOG] );
+	    }
 	    star.num = (int) sp->val[SPECK_ID];
 	    starswap(&star);
 	    wrote = fwrite(&star, sizeof(star), 1, outf);
@@ -1121,7 +1148,7 @@ main(int argc, char *argv[])
 
     progname = argv[0];
 
-    curstate.colorscale = 100.0;
+    curstate.colorscale = -1;
     curstate.has_T0 = 0;
     curstate.port = 3400;
 
@@ -1140,7 +1167,7 @@ Options:\n\
    -y sdbtype\n\
    -g group\n\
    -m mag0         sdb mag = mag0 - log(lum)/(log(100)/5)\n\
-   -c colorscale   sdb color = log10(T)*colorscale\n\
+   -c colorscale   sdb color = log10(T)*colorscale; -c -1 => RGB565 (default)\n\
    -p portno	   listen for HTTP connections on that TCP port\n\
 ", progname);
 	exit(1);