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authorJesse Barnes <jbarnes@virtuousgeek.org>2009-10-01 22:13:34 -0700
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-10-01 22:13:34 -0700
commit29c7fcbf10508ec822ad528928b72702e4c9af01 (patch)
tree975eb9c0c87010ad4a34865706d6365c46cc7de9 /dri2proto.txt
parent00c15f92c1f294d762f2052f1d775c393ebd2432 (diff)
Add swap interval and synchronization support
Based on SGI_video_sync, SGI_swap_control and OML_sync_control, add swap interval and synchronization support to DRI2. Useful for throttling rendering and basic performance metrics. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'dri2proto.txt')
-rw-r--r--dri2proto.txt182
1 files changed, 173 insertions, 9 deletions
diff --git a/dri2proto.txt b/dri2proto.txt
index 1bad3b9..6430b2a 100644
--- a/dri2proto.txt
+++ b/dri2proto.txt
@@ -110,6 +110,17 @@ of the front and back buffers. If the display server supports it, this
operation may be preferred, since it may be easier and/or more performant
for the server to perform a simple buffer swap rather than a blit.
+2.6 Synchronizing rendering
+
+DRI2 provides several methods for synchronizing drawing with various events.
+The protocol for these methods is based on the SGI_video_sync and
+OML_sync_control GLX extensions. Using the DRI2WaitMSC request, a client
+can wait for a specific frame count or divisor/remainder before continuing
+its processing. With the DRI2WaitSBC request, clients can block until a given
+swap count is reached (as incremented by DRI2SwapBuffers). Finally, using
+DRI2SwapBuffers, clients can limit their frame rate by specifying a swap
+interval using the swap interval call (currently only available through GLX)
+or by using the OML swap buffers routine.
⚙ ⚙ ⚙ ⚙ ⚙ ⚙
@@ -297,17 +308,22 @@ The name of this extension is "DRI2".
DRI2SwapBuffers
drawable: DRAWABLE
- buffers: LISTofDRI2BUFFER
+ count: two CARD32s
└───
Errors: Window
Schedule a swap of the front and back buffers with the display
server.
- This request has no reply. The server is expected to either perform
- a buffer exchange or queue one before returning. The client should
- invalidate its render buffers after sending this request, causing
- a subsequent GetBuffers request to get updated buffer info.
+ Returns the swap count value when the swap will actually occur (e.g.
+ the last queued swap count + (pending swap count * swap interval)).
+
+ The client should invalidate its render buffers after sending this
+ request, causing a subsequent GetBuffers request to get updated buffer
+ info.
+
+ This request is only available with protocol version 1.2 or
+ later.
┌───
DRI2GetBuffersWithFormat
@@ -334,6 +350,68 @@ The name of this extension is "DRI2".
This request is only available with protocol version 1.1 or
later.
+┌───
+ DRI2GetMSC
+ drawable: DRAWABLE
+ ▶
+ ust, msc, sbc: CARD64
+└───
+ Errors: Window
+
+ Get the current media stamp counter (MSC) and swap buffer count (SBC)
+ along with the unadjusted system time (UST) when the MSC was last
+ incremented.
+
+ This request is only available with protocol version 1.2 or
+ later.
+
+┌───
+ DRI2WaitMSC
+ drawable: DRAWABLE
+ target_msc: two CARD32s
+ divisor: two CARD32s
+ remainder: two CARD32s
+ ▶
+ ust, msc, sbc: CARD64
+└───
+ Errors: Window
+
+ Blocks the client until either the frame count reaches target_msc or,
+ if the frame count is already greater than target_msc when the request
+ is received, until the frame count % divisor = remainder. If divisor
+ is 0, the client will be unblocked if the frame count is greater than
+ or equal to the target_msc.
+
+ Returns the current media stamp counter (MSC) and swap buffer count
+ (SBC) along with the unadjusted system time (UST) when the MSC was last
+ incremented.
+
+ This request is only available with protocol version 1.2 or
+ later.
+
+┌───
+ DRI2WaitSBC
+ drawable: DRAWABLE
+ target_sbc: two CARD32s
+ ▶
+ ust, msc, sbc: CARD64
+└───
+ Errors: Window
+
+ Blocks the client until the swap buffer count reaches target_sbc. If
+ the swap buffer count is already greater than or equal to target_sbc
+ when the request is recieved, this request will return immediately.
+
+ If target_sbc is 0, this request will block the client until all
+ previous DRI2SwapBuffers requests have completed.
+
+ Returns the current media stamp counter (MSC) and swap buffer count
+ (SBC) along with the unadjusted system time (UST) when the MSC was last
+ incremented.
+
+ This request is only available with protocol version 1.2 or
+ later.
+
⚙ ⚙ ⚙ ⚙ ⚙ ⚙
@@ -558,10 +636,6 @@ A.2 Protocol Requests
5n LISTofDRI2BUFFER buffers
└───
-A.3 Protocol Events
-
-The DRI2 extension specifies no events.
-
┌───
DRI2SwapBuffers
1 CARD8 major opcode
@@ -583,6 +657,96 @@ The DRI2 extension specifies no events.
5n LISTofDRI2BUFFER buffers
└───
+┌───
+ DRI2SwapBuffers
+ 1 CARD8 major opcode
+ 1 7 DRI2 opcode
+ 2 8 length
+ 4 DRAWABLE drawable
+ 4 CARD32 target_msc_hi
+ 4 CARD32 target_msc_lo
+ 4 CARD32 divisor_hi
+ 4 CARD32 divisor_lo
+ 4 CARD32 remainder_hi
+ 4 CARD32 remainder_lo
+ ▶
+ 1 1 Reply
+ 1 unused
+ 2 CARD16 sequence number
+ 4 0 reply length
+ 4 CARD32 swap_hi
+ 4 CARD32 swap_lo
+ 5n LISTofDRI2BUFFER buffers
+└───
+
+┌───
+ DRI2GetMSC
+ 1 CARD8 major opcode
+ 1 7 DRI2 opcode
+ 2 8 length
+ 4 DRAWABLE drawable
+ ▶
+ 1 1 Reply
+ 1 unused
+ 2 CARD16 sequence number
+ 4 0 reply length
+ 4 CARD32 ust_hi
+ 4 CARD32 ust_lo
+ 4 CARD32 msc_hi
+ 4 CARD32 msc_lo
+ 4 CARD32 sbc_hi
+ 4 CARD32 sbc_lo
+└───
+
+┌───
+ DRI2WaitMSC
+ 1 CARD8 major opcode
+ 1 7 DRI2 opcode
+ 2 8 length
+ 4 DRAWABLE drawable
+ 4 CARD32 target_msc_hi
+ 4 CARD32 target_msc_lo
+ 4 CARD32 divisor_hi
+ 4 CARD32 divisor_lo
+ 4 CARD32 remainder_hi
+ 4 CARD32 remainder_lo
+ ▶
+ 1 1 Reply
+ 1 unused
+ 2 CARD16 sequence number
+ 4 0 reply length
+ 4 CARD32 ust_hi
+ 4 CARD32 ust_lo
+ 4 CARD32 msc_hi
+ 4 CARD32 msc_lo
+ 4 CARD32 sbc_hi
+ 4 CARD32 sbc_lo
+└───
+
+┌───
+ DRI2WaitSBC
+ 1 CARD8 major opcode
+ 1 7 DRI2 opcode
+ 2 8 length
+ 4 DRAWABLE drawable
+ 4 CARD32 swap_hi
+ 4 CARD32 swap_lo
+ ▶
+ 1 1 Reply
+ 1 unused
+ 2 CARD16 sequence number
+ 4 0 reply length
+ 4 CARD32 ust_hi
+ 4 CARD32 ust_lo
+ 4 CARD32 msc_hi
+ 4 CARD32 msc_lo
+ 4 CARD32 sbc_hi
+ 4 CARD32 sbc_lo
+└───
+
+A.3 Protocol Events
+
+The DRI2 extension specifies no events.
A.4 Protocol Errors