repeater-patch

来自「gpm-1.20.0.tar.gz」· 代码 · 共 38 行

--- mice.c.orig Tue Sep 25 17:48:30 2001
+++ mice.c      Tue Sep 25 17:48:32 2001
@@ -203,6 +203,21 @@
 int realposx=-1, realposy=-1;
 
 /*========================================================================*/
+/* 
+ * When repeating, it is important not to try to repeat more bits of dx and
+ * dy than the protocol can handle.  Otherwise, you may end up repeating the
+ * low bits of a large value, which causes erratic motion.
+ */
+
+static int limit_delta(int delta, int min, int max)
+{
+    return
+        delta > max ? max :
+        delta < min ? min
+                    : delta;
+}
+
+/*========================================================================*/
 /*
  * Ok, here we are: first, provide the functions; initialization is later.
  * The return value is the number of unprocessed bytes
@@ -423,10 +438,13 @@
 static int R_msc(Gpm_Event *state, int fd)
 {
   signed char buffer[5];
+  int dx, dy;
 
   /* sluggish... */
   buffer[0]=(state->buttons ^ 0x07) | 0x80;
+  dx = limit_delta(state->dx, -256, 254);
   buffer[3] =  state->dx - (buffer[1] = state->dx/2); /* Markus */
+  dy = limit_delta(state->dy, -256, 254);
   buffer[4] = -state->dy - (buffer[2] = -state->dy/2);
   return write(fd,buffer,5);