X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Frd-bomb.c;h=08ec7a753d9c84dd8c2a6accab19ac5b607c8ecd;hb=d5186197bc394e10a4402f7f6d23fbb14103bc50;hp=3e9acbc50e3a5e95d0d892537fd70adab94af867;hpb=4ade52359b6eba3621566dac79793a33aa4c915f;p=xscreensaver

diff --git a/hacks/rd-bomb.c b/hacks/rd-bomb.c
index 3e9acbc5..08ec7a75 100644
--- a/hacks/rd-bomb.c
+++ b/hacks/rd-bomb.c
@@ -1,4 +1,4 @@
-/* xscreensaver, Copyright (c) 1992-2013 Jamie Zawinski <jwz@jwz.org>
+/* xscreensaver, Copyright (c) 1992-2014 Jamie Zawinski <jwz@jwz.org>
  *
  *  reaction/diffusion textures
  *  Copyright (c) 1997 Scott Draves spot@transmeta.com
@@ -95,10 +95,13 @@ pixack_init(struct state *st, int *size_h, int *size_v)
   st->height = get_integer_resource (st->dpy, "height", "Integer");
 
   if (st->width <= 0 && st->height <= 0 && (R & 1))
-    st->width = st->height = 48 + BELLRAND(256);
+    st->width = st->height = 64 + BELLRAND(512);
 
-  if (st->width  <= 0) st->width  = 48 + BELLRAND(256);
-  if (st->height <= 0) st->height = 48 + BELLRAND(256);
+  if (st->width  <= 0) st->width  = 64 + BELLRAND(512);
+  if (st->height <= 0) st->height = 64 + BELLRAND(512);
+
+  if (st->width  > st->xgwa.width)  st->width  = st->xgwa.width;
+  if (st->height > st->xgwa.height) st->height = st->xgwa.height;
 
   /* jwz: when (and only when) XSHM is in use on an SGI 8-bit visual,
      we get shear unless st->width is a multiple of 4.  I don't understand
@@ -233,7 +236,9 @@ pixack_frame(struct state *st, char *pix_buf)
       /* John E. Pearson "Complex Patterns in a Simple System"
 	 Science, July 1993 */
 
-      uvv = (((r1 * r2) >> bps) * r2) >> bps;
+      /* uvv = (((r1 * r2) >> bps) * r2) >> bps; */
+      /* avoid signed integer overflow */
+      uvv = ((((r1 >> 1)* r2) >> bps) * r2) >> (bps - 1);
       switch (st->reaction) {  /* costs 4% */
       case 0:
 	r1 += 4 * (((28 * (mx-r1)) >> 10) - uvv);