Merge commit 'bf803dd851539f0d5f806f12a1e2ab93fdddae08' into garux-merge

[xonotic/netradiant.git] / libs / mathlib / mathlib.c

diff --git a/libs/mathlib/mathlib.c b/libs/mathlib/mathlib.c
index da26a92072ec95c865506ec30ab3e5bfea404f70..9b530e2d487c557b8be48c84b7f4c1484a003c08 100644 (file)
--- a/libs/mathlib/mathlib.c
+++ b/libs/mathlib/mathlib.c
@@ -153,9 +153,7 @@ void _VectorCopy( vec3_t in, vec3_t out ){
        out[2] = in[2];
 }
 
-vec_t VectorNormalize( const vec3_t in, vec3_t out ) {
-
-#if MATHLIB_VECTOR_NORMALIZE_PRECISION_FIX
+vec_t VectorAccurateNormalize( const vec3_t in, vec3_t out ) {
 
        // The sqrt() function takes double as an input and returns double as an
        // output according the the man pages on Debian and on FreeBSD.  Therefore,
@@ -179,26 +177,30 @@ vec_t VectorNormalize( const vec3_t in, vec3_t out ) {
        out[2] = (vec_t) ( z / length );
 
        return (vec_t) length;
+}
 
-#else
+vec_t VectorFastNormalize( const vec3_t in, vec3_t out ) {
 
-       vec_t length, ilength;
+       // SmileTheory: This is ioquake3's VectorNormalize2
+       //              for when accuracy matters less than speed
+       float length, ilength;
 
-       length = (vec_t)sqrt( in[0] * in[0] + in[1] * in[1] + in[2] * in[2] );
-       if ( length == 0 ) {
+       length = in[0] * in[0] + in[1] * in[1] + in[2] * in[2];
+
+       if ( length ) {
+               /* writing it this way allows gcc to recognize that rsqrt can be used */
+               ilength = 1 / (float)sqrt( length );
+               /* sqrt(length) = length * (1 / sqrt(length)) */
+               length *= ilength;
+               out[0] = in[0] * ilength;
+               out[1] = in[1] * ilength;
+               out[2] = in[2] * ilength;
+       }
+       else {
                VectorClear( out );
-               return 0;
        }
 
-       ilength = 1.0f / length;
-       out[0] = in[0] * ilength;
-       out[1] = in[1] * ilength;
-       out[2] = in[2] * ilength;
-
        return length;
-
-#endif
-
 }
 
 vec_t ColorNormalize( const vec3_t in, vec3_t out ) {