a.m32: add states 'uniformceiling' and 'uniformfloor'.

Given highlighted sectors, these take the arithmetic mean of their ceiling's
or floor's (respectively) z, removing the slope bit from all, and setting the
new z to the mean one, rounded down to 1024 Build z units (one PGUP/PGDN).

BUILD_LUNATIC.

git-svn-id: https://svn.eduke32.com/eduke32@4357 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/package/sdk/samples/a.m32

@@ -1563,6 +1563,53 @@ defstate sanitize_underwater_sprites
     printmessage16 "Set xvel=1 on highlighted wall/floor sprites"
 ends
 
+define BZ_MAX 8388608
+
+defstate uniformceil
+    var avgz n
+
+    for i selsectors
+    {
+        ifand sector[i].ceilingstat 2 xor sector[i].ceilingstat 2
+        add avgz sector[i].ceilingz
+        add n 1
+    }
+
+    ife n 0 break
+
+    div avgz n
+    and avgz 0xfffffc00  // round to one PGUP/PNDN unit (1024 z units)
+
+    ifvarge avgz -BZ_MAX ifvarle avgz BZ_MAX nullop
+    else quote "ERROR: average z value outside [-8388608 .. 8388608]"  // BZ_MAX
+
+    for i selsectors
+        set sector[i].ceilingz avgz
+ends
+
+// XXX: CODEDUP
+defstate uniformfloor
+    var avgz n
+
+    for i selsectors
+    {
+        ifand sector[i].floorstat 2 xor sector[i].floorstat 2
+        add avgz sector[i].floorz
+        add n 1
+    }
+
+    ife n 0 break
+
+    div avgz n
+    and avgz 0xfffffc00  // round to one PGUP/PNDN unit (1024 z units)
+
+    ifvarge avgz -BZ_MAX ifvarle avgz BZ_MAX nullop
+    else quote "ERROR: average z value outside [-8388608 .. 8388608]"  // BZ_MAX
+
+    for i selsectors
+        set sector[i].floorz avgz
+ends
+
 // This must be *compiled* with script_expertmode
 /*
 defstate setstartpos

polymer/eduke32/source/m32exec.c

@@ -149,7 +149,7 @@ void VM_OnEvent(register int32_t iEventID, register int32_t iActor)
         int32_t localvars[M32_LOCALS_FIXEDNUM];
 #endif
 
-        // needed since any read access before initialization would cause undefined behaviour
+        // Initialize 'state'-local variables to 0.
         if (aEventNumLocals[iEventID] > 0)
             Bmemset(localvars, 0, aEventNumLocals[iEventID]*sizeof(int32_t));