Merge pull request #6 from thekovic/hash-fix

Fix hash calculation for texture names that are too long

graphics/textures/d64hash.js

@@ -4,29 +4,23 @@
 QForm = {};
 
 QForm.onEncode = function () {
-
-	var texture = document.getElementById("texname").value; // get the texture name
-	var hash = 1315423911; // set initial hash value
-	var i = 0;
-
-	texture = texture.toUpperCase(); // convert to upper case
+    // get the texture name and convert to upper case
+    var texture = document.getElementById("texname").value.toUpperCase();
+    // clamp the number of characters we check to 8 because lumpinfo_t
+    // can only store 8 bytes (texture names in WAD can only be 8 characters long)
+    var repetitions = texture.length < 8 ? texture.length : 8;
+    // set initial hash value
+    var hash = 1315423911;
 
-    for (let i = 0; i < texture.length; i++)
+    for (let i = 0; i < repetitions; i++)
     {
         hash ^= ((hash << 5) + texture.charCodeAt(i) + (hash >> 2));
     }
-
-	hash = (hash >>>0) % 65536; // make it show as an unsigned int
-
-	// Special case for blank texture
-	if (texture == "BLANK")
-	{
-		hash = -6735;
-	}
-
+
+    // make it show as 16-bit unsigned integer
+    hash = (hash >>> 0) % 65536;
 
-	document.getElementById("hashnum").value = hash;
-
+    document.getElementById("hashnum").value = hash;
 };