Add several convenience functions. Fix some bugs regarding misuse of readparam()

1 files changed, 123 insertions, 0 deletions

diff --git a/npc/functions/math.txt b/npc/functions/math.txt
new file mode 100644
index 00000000..9c93fbb7
--- /dev/null
+++ b/npc/functions/math.txt
@@ -0,0 +1,123 @@
+// Evol functions.
+// Authors:
+//    4144
+//    Reid
+// Description:
+//    Math functions
+
+
+// abs(<int>)
+//    returns the absolute value of the passed integer
+
+function	script	abs	{
+    .@n = getarg(0);
+    return .@n >= 0 ? .@n : -.@n;
+}
+
+
+
+// lognbaselvl({<multiplicator>{, <min value>}})
+//     returns BaseLevel * logn (BaseLevel * alpha).
+
+function	script	lognbaselvl	{
+    .@alpha = getarg(0, 1);
+    .@min = getarg(1, 1);
+    .@ret = 0;
+    .@pc_level = BaseLevel * .@alpha;
+
+    while (.@pc_level >>= 1)
+    {
+        ++.@ret;
+    }
+    .@ret *= BaseLevel;
+
+    if (.@ret <= .@min)
+    {
+        .@ret = .@min;
+    }
+
+    return .@ret;
+}
+
+// log2(<int>)
+//    returns the log base 2 of the passed integer, up to 20 (2**20=1.048.576) (round down always)
+
+function	script	log2	{
+    .@v=abs(getarg(0));
+    .@ok=0;
+    .@i=0;
+    if (.@v < 1)
+        return -1;
+
+    freeloop(true);
+    while (!.@ok) {
+        // exact match
+        if (2**.@i == .@v) {
+            .@ok=1;
+        // inexact match, or limit exceeded
+        } else if (2**.@i >= .@v || .@i > 20) {
+            .@ok=1;
+            .@i-=1; // round down
+        // not yet
+        } else {
+            .@i+=1;
+        }
+    }
+    freeloop(false);
+
+    return .@i;
+}
+
+
+// result is: lower < target <= higher
+// is_between ( lower, higher, target)
+function	script	is_between	{
+    .@val=getarg(2);
+    .@min=getarg(0);
+    .@max=getarg(1);
+    return (.@min < .@val && .@val <= .@max);
+}
+
+
+// forces the equation: lower <= target <= higher.
+// Note it still works if higher and target values are swapped.
+// limit ( lower, target, higher)
+function	script	limit	{
+    return max(getarg(0), min(getarg(1), getarg(2)));
+}
+
+
+// result is the ponderate average.
+// ponderate_avg ( arg1, sub1, arg2, sub2)
+function	script	ponderate_avg	{
+    .@a1=getarg(0);
+    .@s1=getarg(1);
+    .@a2=getarg(2);
+    .@s2=getarg(3);
+
+    .@h1=.@a1*.@s1;
+    .@h2=.@a2*.@s2;
+    .@dd=.@s1+.@s2;
+
+    return (.@h1+.@h2)/.@dd;
+}
+
+// bitmask_count(<int>)
+//    returns the number of bits set in <int> (max. 4096)
+
+function	script	bitmask_count	{
+    .@n = getarg(0); // Number evaluated
+    .@p=0; // Bits set/unset
+    .@s=0; // Stack and Check
+    .@m=0; // Memory
+
+    // Loop only as needed
+    while (.@s < .@n) {
+        .@s=2**.@m;
+        if (.@n & .@s)
+            .@p++;
+        .@m++;
+    }
+    return .@p;
+}
+