Add bitwise functions from TMW rEvolt

3 files changed, 68 insertions, 19 deletions

diff --git a/npc/functions/bitwise.txt b/npc/functions/bitwise.txt
new file mode 100644
index 000000000..f7e595a27
--- /dev/null
+++ b/npc/functions/bitwise.txt
@@ -0,0 +1,67 @@
+// The Mana World Script
+// Author: Gumi, Jesusalva
+/**
+ * Gets a bitmasked value in from an integer. If the shift is omitted, it will
+ * be deduced from the mask.
+ *
+ * @arg 0 - the variable
+ * @arg 1 - mask
+ * @arg 2 - shift
+ */
+function	script	bitwise_get	{
+    .@shift = getarg(2, 0);
+
+    if (getargcount() < 3) {
+        // guess the shift from the mask:
+        for (.@shift = 0; .@shift < 32; ++.@shift) {
+            if ((getarg(1) & (1 << .@shift)) != 0) {
+                break;
+            }
+        }
+    }
+
+    return (getarg(0) & getarg(1)) >> .@shift;
+}
+
+/**
+ * sets a bitmasked value in a variable
+ *
+ * @arg 0 - the target variable
+ * @arg 1 - mask
+ * @arg 2 - shift
+ * @arg 3 - new value
+ * @return a reference to the variable
+ */
+function	script	bitwise_set	{
+    if (getargcount() < 4) {
+        // guess the shift from the mask:
+        for (.@shift = 0; .@shift < 32; ++.@shift) {
+            if ((getarg(1) & (1 << .@shift)) != 0) {
+                break;
+            }
+        }
+
+        return set(getarg(0), (getarg(0) & ~(getarg(1))) | (getarg(2, 0) << .@shift));
+    }
+
+    return set(getarg(0), (getarg(0) & ~(getarg(1))) | (getarg(3, 0) << getarg(2, 0)));
+}
+
+// bitmask_count(<int>)
+//    returns the number of bits set in <int> (up to 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;
+}
+
diff --git a/npc/functions/math.txt b/npc/functions/math.txt
index 9c93fbb74..fc27bec40 100644
--- a/npc/functions/math.txt
+++ b/npc/functions/math.txt
@@ -102,22 +102,3 @@ function	script	ponderate_avg	{
     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;
-}
-
diff --git a/npc/scripts.conf b/npc/scripts.conf
index 290624ea8..aad39c382 100644
--- a/npc/scripts.conf
+++ b/npc/scripts.conf
@@ -5,6 +5,7 @@
 "npc/functions/string.txt",
 "npc/functions/main.txt",
 "npc/functions/array.txt",
+"npc/functions/bitwise.txt",
 "npc/functions/math.txt",
 "npc/functions/util.txt",