build: Fix inexact calculation of required materials

[empserver] / src / lib / commands / buil.c

diff --git a/src/lib/commands/buil.c b/src/lib/commands/buil.c
index 9495565e9e7c5d1970936c6869a50dd543b70e64..700113047aa9b8c8382247518f7729900fc4cf68 100644 (file)
--- a/src/lib/commands/buil.c
+++ b/src/lib/commands/buil.c
@@ -1,6 +1,6 @@
 /*
  *  Empire - A multi-player, client/server Internet based war game.
- *  Copyright (C) 1986-2014, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *  Copyright (C) 1986-2015, Dave Pare, Jeff Bailey, Thomas Ruschak,
  *                Ken Stevens, Steve McClure, Markus Armbruster
  *
  *  Empire is free software: you can redistribute it and/or modify
@@ -28,7 +28,7 @@
  *
  *  Known contributors to this file:
  *     Steve McClure, 1998-2000
- *     Markus Armbruster, 2004-2014
+ *     Markus Armbruster, 2004-2015
  */
 
 #include <config.h>
@@ -652,8 +652,8 @@ static int
 sector_can_build(struct sctstr *sp, short mat[], int work,
                 int effic, char *what)
 {
-    int i, avail, ret;
-    double needed;
+    int i, avail, ret, req;
+    double used;
 
     if (player->god)
        return 1;               /* Deity builds ex nihilo */
@@ -674,14 +674,15 @@ sector_can_build(struct sctstr *sp, short mat[], int work,
 
     ret = 1;
     for (i = I_NONE + 1; i <= I_MAX; i++) {
-       needed = mat[i] * (effic / 100.0);
-       if (sp->sct_item[i] < needed) {
-           pr("Not enough %s in %s (need %g more)\n",
+       used = mat[i] * effic;
+       req = (used + 99) / 100;
+       if (sp->sct_item[i] < req) {
+           pr("Not enough %s in %s (need %d more)\n",
               ichr[i].i_name, xyas(sp->sct_x, sp->sct_y, player->cnum),
-              ceil(needed - sp->sct_item[i]));
+              req - sp->sct_item[i]);
            ret = 0;
        }
-       mat[i] = roundavg(needed);
+       mat[i] = roundavg(used / 100.0);
     }
 
     return ret;