[src/trunk]: src/external/bsd/tmux/dist Replace needless use of double math j...

[he <he%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/471505bd994e
branches:  trunk
changeset: 768598:471505bd994e
user:      he <he%NetBSD.org@localhost>
date:      Mon Aug 22 06:52:35 2011 +0000

description:
Replace needless use of double math just to compare colour distances
with integer arithmetic.  Reported to and discussed with upstream maintainer.

diffstat:

 external/bsd/tmux/dist/colour.c |  17 ++++++++---------
 1 files changed, 8 insertions(+), 9 deletions(-)

diffs (64 lines):

diff -r c00a8a5e226e -r 471505bd994e external/bsd/tmux/dist/colour.c
--- a/external/bsd/tmux/dist/colour.c   Mon Aug 22 02:37:15 2011 +0000
+++ b/external/bsd/tmux/dist/colour.c   Mon Aug 22 06:52:35 2011 +0000
@@ -1,4 +1,4 @@
-/* $Id: colour.c,v 1.1.1.2 2011/08/17 18:40:04 jmmv Exp $ */
+/* $Id: colour.c,v 1.2 2011/08/22 06:52:35 he Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicm%users.sourceforge.net@localhost>
@@ -19,7 +19,6 @@
 #include <sys/types.h>
 
 #include <ctype.h>
-#include <math.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -41,7 +40,7 @@
 struct colour_rgb *colour_rgb_256;
 
 void   colour_rgb_generate256(void);
-double colour_rgb_distance(struct colour_rgb *, struct colour_rgb *);
+u_int  colour_rgb_distance(struct colour_rgb *, struct colour_rgb *);
 int    colour_rgb_find(struct colour_rgb *);
 
 /* Generate 256 colour RGB table. */
@@ -90,8 +89,8 @@
        }
 }
 
-/* Get colour RGB distance. */
-double
+/* Get a measure of colour RGB distance. */
+u_int
 colour_rgb_distance(struct colour_rgb *rgb1, struct colour_rgb *rgb2)
 {
        int     r, g, b;
@@ -99,22 +98,22 @@
        r = rgb1->r - rgb2->r;
        g = rgb1->g - rgb2->g;
        b = rgb1->b - rgb2->b;
-       return (sqrt(r * r + g * g + b * b));
+       return (r * r + g * g + b * b);
 }
 
 /* Work out the nearest colour from the 256 colour set. */
 int
 colour_rgb_find(struct colour_rgb *rgb)
 {
-       double  distance, lowest;
+       u_int   distance, lowest;
        u_int   colour, i;
 
        if (colour_rgb_256 == NULL)
                colour_rgb_generate256();
 
        colour = 16;
-       lowest = INFINITY;
-       for (i = 0; i < 240; i++) {
+       lowest = UINT_MAX;
+       for (i = 1; i < 240; i++) {
                distance = colour_rgb_distance(&colour_rgb_256[i], rgb);
                if (distance < lowest) {
                        lowest = distance;