Added support for DirectDraw overlays using the XVideo extension.
diff --git a/include/ddraw.h b/include/ddraw.h
index 3d8c176..d40ff31 100644
--- a/include/ddraw.h
+++ b/include/ddraw.h
@@ -811,6 +811,31 @@
#define DDOVERFX_MIRRORLEFTRIGHT 0x00000002
#define DDOVERFX_MIRRORUPDOWN 0x00000004
+/* UpdateOverlay flags */
+#define DDOVER_ALPHADEST 0x00000001
+#define DDOVER_ALPHADESTCONSTOVERRIDE 0x00000002
+#define DDOVER_ALPHADESTNEG 0x00000004
+#define DDOVER_ALPHADESTSURFACEOVERRIDE 0x00000008
+#define DDOVER_ALPHAEDGEBLEND 0x00000010
+#define DDOVER_ALPHASRC 0x00000020
+#define DDOVER_ALPHASRCCONSTOVERRIDE 0x00000040
+#define DDOVER_ALPHASRCNEG 0x00000080
+#define DDOVER_ALPHASRCSURFACEOVERRIDE 0x00000100
+#define DDOVER_HIDE 0x00000200
+#define DDOVER_KEYDEST 0x00000400
+#define DDOVER_KEYDESTOVERRIDE 0x00000800
+#define DDOVER_KEYSRC 0x00001000
+#define DDOVER_KEYSRCOVERRIDE 0x00002000
+#define DDOVER_SHOW 0x00004000
+#define DDOVER_ADDDIRTYRECT 0x00008000
+#define DDOVER_REFRESHDIRTYRECTS 0x00010000
+#define DDOVER_REFRESHALL 0x00020000
+#define DDOVER_DDFX 0x00080000
+#define DDOVER_AUTOFLIP 0x00100000
+#define DDOVER_BOB 0x00200000
+#define DDOVER_OVERRIDEBOBWEAVE 0x00400000
+#define DDOVER_INTERLEAVED 0x00800000
+
/* DDCOLORKEY.dwFlags */
#define DDPF_ALPHAPIXELS 0x00000001
#define DDPF_ALPHA 0x00000002
