replace 1.0/sqrt() with inversesqrt()

diff --git a/progs/glsl/CH11-bumpmap.frag b/progs/glsl/CH11-bumpmap.frag
index 063576f5a3c29fa9ff95a27f5f89b0a3e09d16ca..e12c5d374cd7cdad034204a5668696af6b3a51af 100644 (file)
--- a/progs/glsl/CH11-bumpmap.frag
+++ b/progs/glsl/CH11-bumpmap.frag
@@ -24,7 +24,7 @@ void main()
 
     float d, f;
     d = p.x * p.x + p.y * p.y;
-    f = 1.0 / sqrt(d + 1.0);
+    f = inversesqrt(d + 1.0);
 
     if (d >= BumpSize)
         { p = vec2(0.0); f = 1.0; }