Add support for the 'Present' extension. [v3]

This makes updating the eyes nicely vblank synchronized.

v2:
	Ensure extensions exist before calling query_version

	These calls add calls to xcb_get_extension_data before calling
	query_version calls, as those calls will mark the connection
	with an error if made against an X server without the
	extension present.

	Suggested-by: Uli Schlachter <psychon@znc.in>

v3:
	check the 'present' field in the return from
	xcb_get_extension_data; the xcb_get_extension_data call will
	always succeed (save for out of memory), the only way to tell
	if the extension is supported in the target X server is to
	test the 'present' field in the query extension reply value.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/EyesP.h b/EyesP.h
index 159d7f3..29fe8a3 100644
--- a/EyesP.h
+++ b/EyesP.h
@@ -8,6 +8,13 @@
 #include <X11/extensions/Xrender.h>
 #endif
 #include "transform.h"
+#ifdef PRESENT
+#include <X11/Xlib-xcb.h>
+#include <xcb/xcb.h>
+#include <xcb/present.h>
+#include <xcb/xfixes.h>
+#include <xcb/damage.h>
+#endif
 
 #define SEG_BUFF_SIZE		128
 
@@ -31,9 +38,17 @@ typedef struct {
 	 Picture	picture;
 	 Picture	fill[PART_SHAPE];
 #endif
+#ifdef PRESENT
+         Pixmap         back_buffer;
+         xcb_damage_damage_t back_damage;
+         xcb_xfixes_region_t back_region;
+         Boolean        present;
+#endif
 	 Boolean    	distance;
    } EyesPart;
 
+#define xt_xcb(w)       (XGetXCBConnection(XtDisplay(w)))
+
 /* Full instance record declaration */
 typedef struct _EyesRec {
    CorePart core;