NX/VITA: Add crc16 builtin

source/crc.c

@@ -92,3 +92,24 @@ unsigned short CRC_Block (const byte *start, int count)
 
 	return crc;
 }
+
+//
+// taken from darkplaces -- just a shortcut for initialization for
+// use with string-hashing (just progs, likely). -- cypress (07 jan 2024)
+//
+
+unsigned short CRC_Block2(const unsigned char *data, size_t size)
+{
+	unsigned short crc = CRC_INIT_VALUE;
+	while (size--)
+		crc = (crc << 8) ^ crctable[(crc >> 8) ^ (*data++)];
+	return crc ^ CRC_XOR_VALUE;
+}
+
+unsigned short CRC_Block_CaseInsensitive(const unsigned char *data, size_t size)
+{
+	unsigned short crc = CRC_INIT_VALUE;
+	while (size--)
+		crc = (crc << 8) ^ crctable[(crc >> 8) ^ (tolower(*data++))];
+	return crc ^ CRC_XOR_VALUE;
+}

source/crc.h

@@ -29,5 +29,8 @@ void CRC_ProcessByte(unsigned short *crcvalue, byte data);
 unsigned short CRC_Value(unsigned short crcvalue);
 unsigned short CRC_Block (const byte *start, int count); //johnfitz -- texture crc
 
+unsigned short CRC_Block2(const unsigned char *data, size_t size);
+unsigned short CRC_Block_CaseInsensitive(const unsigned char *data, size_t size);
+
 #endif	/* _QUAKE_CRC_H */
 

source/pr_cmds.c

@@ -3241,6 +3241,21 @@ void PF_strtolower (void)
 	G_INT (OFS_RETURN) = PR_SetEngineString (result);
 }
 
+/*
+=================
+PF_crc16
+
+float crc16 (float, string)
+=================
+*/
+void PF_crc16(void)
+{
+	int insens = G_FLOAT(OFS_PARM0);
+	char *s = G_STRING(OFS_PARM1);
+
+	G_FLOAT(OFS_RETURN) = (unsigned short) ((insens ? CRC_Block_CaseInsensitive : CRC_Block2) ((unsigned char *) s, strlen(s)));
+}
+
 /*
 =================
 PF_strlen
@@ -3937,7 +3952,7 @@ static builtin_t pr_builtin[] =
 	NULL, 						// #491
 	NULL, 						// #492
 	NULL, 						// #493
-	NULL, 						// #494
+	PF_crc16, 					// #494
 	NULL, 						// #495
 	NULL, 						// #496
 	NULL, 						// #497