From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Sun, 2 May 2021 03:15:30 +0000 (-0700)
Subject: use floating point math functions to squash a -Wfloat-conversion warning
X-Git-Tag: 2.47.2~7^2~4
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=40d34a600fc8fdba845a610e8007713b19b4cc56;p=graphviz

use floating point math functions to squash a -Wfloat-conversion warning

The function sqrt operates on doubles, which was triggering a -Wfloat-conversion
compiler warning. The float version of this function is sqrtf, but we can
further abbreviate this operation by observing it is computing the hypotenuse of
a right-angled triangle and use the library function for that instead.
---

diff --git a/lib/neatogen/sgd.c b/lib/neatogen/sgd.c
index bd7ad6132..f66003942 100644
--- a/lib/neatogen/sgd.c
+++ b/lib/neatogen/sgd.c
@@ -13,7 +13,7 @@ static float calculate_stress(float *pos, term_sgd *terms, int n_terms) {
     for (ij=0; ij<n_terms; ij++) {
         float dx = pos[2*terms[ij].i] - pos[2*terms[ij].j];
         float dy = pos[2*terms[ij].i+1] - pos[2*terms[ij].j+1];
-        float r = sqrt(dx*dx + dy*dy) - terms[ij].d;
+        float r = hypotf(dx, dy) - terms[ij].d;
         stress += terms[ij].w * (r * r);
     }
     return stress;