Remove SBC, use CompleteNotify for both Region and NotifyMSC

SBC is entire a client-side notion, so remove it from the protocol.
No need to have two events with the same content, but we do need to
tell which request generated the event so stick a new field in some
spare bytes

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

3 files changed, 40 insertions, 39 deletions

diff --git a/presentproto.h b/presentproto.h
index 44dc96c..3e2c0bb 100644
--- a/presentproto.h
+++ b/presentproto.h
@@ -132,16 +132,15 @@ typedef struct {
     CARD16 sequenceNumber B16;
     CARD32 length;
     CARD16 evtype B16;
-    CARD16 pad2 B16;
+    CARD16 kind B16;
     CARD32 eid B32;
     Window window B32;
     CARD32 serial B32;
     CARD64 ust;
+
     CARD64 msc;
-    CARD64 sbc;
-} xPresentCompleteNotify, xPresentMSCNotify;
-#define sz_xPresentCompleteNotify 48
-#define sz_xPresentMSCNotify 48
+} xPresentCompleteNotify;
+#define sz_xPresentCompleteNotify 40
 
 typedef struct {
     CARD8 type;
diff --git a/presentproto.txt b/presentproto.txt
index 8f64779..6b226ab 100644
--- a/presentproto.txt
+++ b/presentproto.txt
@@ -29,10 +29,17 @@ PRESENTEVENTID { XID }
 	events. Multiple event IDs can be allocated to provide
 	multiple distinct event delivery contexts.
 
+PRESENTEVENTTYPE { PresentConfigureNotify,
+		   PresentCompleteNotify,
+		   PresentRedirectNotify }
+
 PRESENTEVENTMASK { PresentConfigureNotifyMask,
 		   PresentCompleteNotifyMask,
 		   PresentSubredirectNotifyMask }
 
+PRESENTCOMPLETEKIND { PresentCompleteKindRegion,
+		      PresentCompleteKindMSCNotify }
+
 The Present extension also uses the Sync extension Fence data type to
 provide synchronization for pixmaps.
 
@@ -140,6 +147,9 @@ The name of this extension is "Present"
 	field. Otherwise, the presentation will occur after the next
 	field where msc % 'divisor' == 'remainder'.
 	
+	After the presentation occurs, a PresentCompleteNotify event
+	with kind PresentCompleteKindRegion will be generated.
+
 	If 'window' is destroyed before the presentation occurs, then
 	the presentation action will not be completed.
 
@@ -162,7 +172,8 @@ The name of this extension is "Present"
 └───
 	Errors: Window
 
-	Delivers a PresentMSCNotifyEvent after time specified by
+	Delivers a PresentCompleteNotifyEvent with kind
+	PresentCompleteKindNotifyMSC after the time specified by
 	'target-msc', 'divisor' and 'remainder').
 
 	'serial' is an arbitrary client-specified value which will be
@@ -242,41 +253,28 @@ The name of this extension is "Present"
 	type: CARD8			XGE event type (35)
 	extension: CARD8		Present extension request number
 	length: CARD16			2
-	evtype: CARD16			Present_CompleteNotify
+	evtype: PRESENTEVENTTYPE	PresentCompleteNotify
 	eventID: PRESENTEVENTID
 	window: WINDOW
+	kind: PRESENTCOMPLETEKIND
 	serial: CARD32
 	ust: CARD64
 	msc: CARD64
-	sbc: CARD64
 └───
 
-	CompleteNotify events are delivered when a PresentRegion
-	operation has completed and the specified contents are being
-	displayed. 'serial' is the value provided in the generating
-	PresentRegion request. 'sbc', 'msc' and 'ust' indicate the
-	swap count, frame count and system time when the presentation
-	actually occurred.
+	CompleteNotify events are delivered when a PresentRegion or
+	PresentNotifyMSC operation has completed.
 
-┌───
-    PresentMSCNotify
-	type: CARD8			XGE event type (35)
-	extension: CARD8		Present extension request number
-	length: CARD16			2
-	evtype: CARD16			Present_MSCNotify
-	eventID: PRESENTEVENTID
-	window: WINDOW
-	serial: CARD32
-	ust: CARD64
-	msc: CARD64
-	sbc: CARD64
-└───
+	'kind' is PresentCompleteKindRegion when generated by a
+	PresentRegion operation completion or
+	PresentCompleteKindNotifyMsc when generated by a
+	PresentNotifyMSC operation completion.
+
+	'serial' is the value provided in the generating PresentRegion
+	request.
 
-	MSCNotify events are delivered when a PresentNotifyMSC
-	operation has completed. 'serial' is the value provided in the
-	generating PresentNotifyMSC request. 'sbc', 'msc' and 'ust'
-	indicate the swap count, frame count and system time when the
-	operation completed.
+	'msc' and 'ust' indicate the frame count and system time when
+	the presentation actually occurred.
 
 ┌───
     PresentRedirectNotify
@@ -410,13 +408,12 @@ A.3 Protocol Events
 	2	CARD16			sequence number
 	4	2			length
 	2	1			PresentCompleteNotify
-	2				unused
+	2	CARD16			kind
 	4	CARD32			event id
 	4	Window			window
 	4	CARD32			serial
 	8	CARD64			ust
 	8	CARD64			msc
-	8	CARD64			sbc
 └───
 
 A.4 Protocol Errors
diff --git a/presenttokens.h b/presenttokens.h
index d829f11..dbfdb36 100644
--- a/presenttokens.h
+++ b/presenttokens.h
@@ -30,6 +30,7 @@
 #define PresentNumberErrors		0
 #define PresentNumberEvents		0
 
+/* Requests */
 #define X_PresentQueryVersion		0
 #define X_PresentRegion			1
 #define X_PresentNotifyMSC		2
@@ -37,19 +38,23 @@
 
 #define PresentNumberRequests		4
 
+/* Events */
 #define PresentConfigureNotify	0
 #define PresentCompleteNotify	1
-#define PresentMSCNotify	2
-#define PresentRedirectNotify	3
+#define PresentRedirectNotify	2
 
+/* Event Masks */
 #define PresentConfigureNotifyMask      1
 #define PresentCompleteNotifyMask       2
-#define PresentMSCNotifyMask            4
-#define PresentRedirectNotifyMask       8
+#define PresentRedirectNotifyMask       4
 
 #define PresentAllEvents   (PresentConfigureNotifyMask |        \
                             PresentCompleteNotifyMask |         \
-                            PresentMSCNotifyMask |              \
                             PresentRedirectNotifyMask)
 
+/* Complete Kinds */
+
+#define PresentCompleteKindRegion       0
+#define PresentCompleteKindNotifyMSC    1
+
 #endif