Added Fran Moreno's Kd-Tree implementation and RGBE functions.

rgbe.cpp

@@ -0,0 +1,40 @@
+#include <cmath>
+
+#include "rgbe.hpp"
+
+/* standard conversion from float pixels to rgbe pixels */
+/* note: you can remove the "inline"s if your compiler complains about it */
+void float2rgbe(unsigned char rgbe[4], float red, float green, float blue) {
+  float v;
+  int e;
+
+  v = red;
+  if (green > v) v = green;
+  if (blue > v) v = blue;
+  if (v < 1e-32) {
+    rgbe[0] = rgbe[1] = rgbe[2] = rgbe[3] = 0;
+  }
+  else {
+    v = frexp(v,&e) * 256.0/v;
+    rgbe[0] = (unsigned char) (red * v);
+    rgbe[1] = (unsigned char) (green * v);
+    rgbe[2] = (unsigned char) (blue * v);
+    rgbe[3] = (unsigned char) (e + 128);
+  }
+}
+
+/* standard conversion from rgbe to float pixels */
+/* note: Ward uses ldexp(col+0.5,exp-(128+8)).  However we wanted pixels */
+/*       in the range [0,1] to map back into the range [0,1].            */
+void rgbe2float(float & red, float & green, float & blue, unsigned char rgbe[4]) {
+  float f;
+
+  if (rgbe[3]) {   /*nonzero pixel*/
+    f = ldexp(1.0,rgbe[3]-(int)(128+8));
+    red = rgbe[0] * f;
+    green = rgbe[1] * f;
+    blue = rgbe[2] * f;
+  }
+  else
+    red = green = blue = 0.0;
+}