replace hypotenuse calculation in arrow_gen with a call to hypot

The function hypot is available in C99 and has the potential to compute the same
operation more efficiently and with greater precision.

diff --git a/lib/common/arrows.c b/lib/common/arrows.c
index 8f3b2c22f47a3a13506868b2c55aea58fe4f5142..ef9d25692b01bc1cb6619fd1b8cc0bc0d3d18d12 100644 (file)
--- a/lib/common/arrows.c
+++ b/lib/common/arrows.c
@@ -755,7 +755,7 @@ void arrow_gen(GVJ_t * job, emit_state_t emit_state, pointf p, pointf u, double
     u.x -= p.x;
     u.y -= p.y;
     /* the EPSILONs are to keep this stable as length of u approaches 0.0 */
-    s = ARROW_LENGTH / (sqrt(u.x * u.x + u.y * u.y) + EPSILON);
+    s = ARROW_LENGTH / (hypot(u.x, u.y) + EPSILON);
     u.x += (u.x >= 0.0) ? EPSILON : -EPSILON;
     u.y += (u.y >= 0.0) ? EPSILON : -EPSILON;
     u.x *= s;