Merge MR 'Reduce RAM usage in various structures'

As I understand in BIH_UNORDERED only children array is used, while front, back, min and max are never written. Opposite true for other node types.

On side note sizes should be explicitly added to ints.

See https://gitlab.com/xonotic/darkplaces/-/merge_requests/149

Signed-off-by: bones_was_here <bones_was_here@xonotic.au>

bih.h

@@ -39,14 +39,18 @@ typedef struct bih_node_s
 	// TODO: move bounds data to parent node and remove it from leafs?
 	float mins[3];
 	float maxs[3];
-	// node indexes of children (always > this node's index)
-	int front;
-	int back;
-	// interval of children
-	float frontmin; // children[0]
-	float backmax; // children[1]
-	// BIH_UNORDERED uses this for a list of leafindex (all >= 0), -1 = end of list
-	int children[BIH_MAXUNORDEREDCHILDREN];
+	union {
+		struct{
+			// node indexes of children (always > this node's index)
+			int front;
+			int back;
+			// interval of children
+			float frontmin; // children[0]
+			float backmax; // children[1]
+		};
+		// BIH_UNORDERED uses this for a list of leafindex (all >= 0), -1 = end of list
+		int children[BIH_MAXUNORDEREDCHILDREN];
+	};
 }
 bih_node_t;
 

com_crc16.c

@@ -36,7 +36,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #define CRC_INIT_VALUE	0xffff
 #define CRC_XOR_VALUE	0x0000
 
-static unsigned short crctable[256] =
+static const u16 crctable[256] =
 {
 	0x0000,	0x1021,	0x2042,	0x3063,	0x4084,	0x50a5,	0x60c6,	0x70e7,
 	0x8108,	0x9129,	0xa14a,	0xb16b,	0xc18c,	0xd1ad,	0xe1ce,	0xf1ef,
@@ -89,7 +89,7 @@ unsigned short CRC_Block_CaseInsensitive(const unsigned char *data, size_t size)
 }
 
 // QuakeWorld
-static unsigned char chktbl[1024 + 4] =
+static const u8 chktbl[1024 + 4] =
 {
 	0x78,0xd2,0x94,0xe3,0x41,0xec,0xd6,0xd5,0xcb,0xfc,0xdb,0x8a,0x4b,0xcc,0x85,0x01,
 	0x23,0xd2,0xe5,0xf2,0x29,0xa7,0x45,0x94,0x4a,0x62,0xe3,0xa5,0x6f,0x3f,0xe1,0x7a,
@@ -131,7 +131,7 @@ static unsigned char chktbl[1024 + 4] =
 // QuakeWorld
 unsigned char COM_BlockSequenceCRCByteQW(unsigned char *base, int length, int sequence)
 {
-	unsigned char *p;
+	const unsigned char *p;
 	unsigned char chkb[60 + 4];
 
 	p = chktbl + (sequence % (sizeof(chktbl) - 8));