[Mesa-dev] [PATCH 3/3] dri3: Add GLX_EXT_buffer_age support

[Adel Gadllah]

---
 src/glx/dri2_glx.c      |  1 +
 src/glx/dri3_glx.c      | 18 ++++++++++++++++++
 src/glx/dri3_priv.h     |  2 ++
 src/glx/glx_pbuffer.c   |  8 ++++++++
 src/glx/glxclient.h     |  1 +
 src/glx/glxextensions.c |  1 +
 src/glx/glxextensions.h |  1 +
 7 files changed, 32 insertions(+)

diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
index 67fe9c1..146802a 100644
--- a/src/glx/dri2_glx.c
+++ b/src/glx/dri2_glx.c
@@ -1288,6 +1288,7 @@ dri2CreateScreen(int screen, struct glx_display * priv)
    psp->waitForSBC = NULL;
    psp->setSwapInterval = NULL;
    psp->getSwapInterval = NULL;
+   psp->getBufferAge = NULL;
 
    if (pdp->driMinor >= 2) {
       psp->getDrawableMSC = dri2DrawableGetMSC;
diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
index 70ec057..697d448 100644
--- a/src/glx/dri3_glx.c
+++ b/src/glx/dri3_glx.c
@@ -1345,6 +1345,7 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
          target_msc = priv->msc + priv->swap_interval * (priv->send_sbc - priv->recv_sbc);
 
       priv->buffers[buf_id]->busy = 1;
+      priv->buffers[buf_id]->last_swap = priv->swap_count;
       xcb_present_pixmap(c,
                          priv->base.xDrawable,
                          priv->buffers[buf_id]->pixmap,
@@ -1379,11 +1380,25 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
       xcb_flush(c);
       if (priv->stamp)
          ++(*priv->stamp);
+
+      priv->swap_count++;
    }
 
    return ret;
 }
 
+static int
+dri3_get_buffer_age(__GLXDRIdrawable *pdraw)
+{
+  struct dri3_drawable *priv = (struct dri3_drawable *) pdraw;
+  const struct dri3_buffer *const back = dri3_back_buffer(priv);
+
+  if (back->last_swap != 0)
+     return priv->swap_count - back->last_swap;
+  else
+     return 0;
+}
+
 /** dri3_open
  *
  * Wrapper around xcb_dri3_open
@@ -1742,6 +1757,9 @@ dri3_create_screen(int screen, struct glx_display * priv)
    psp->copySubBuffer = dri3_copy_sub_buffer;
    __glXEnableDirectExtension(&psc->base, "GLX_MESA_copy_sub_buffer");
 
+   psp->getBufferAge = dri3_get_buffer_age;
+   __glXEnableDirectExtension(&psc->base, "GLX_EXT_buffer_age");
+
    free(driverName);
    free(deviceName);
 
diff --git a/src/glx/dri3_priv.h b/src/glx/dri3_priv.h
index 1d124f8..d00440a 100644
--- a/src/glx/dri3_priv.h
+++ b/src/glx/dri3_priv.h
@@ -97,6 +97,7 @@ struct dri3_buffer {
    uint32_t     cpp;
    uint32_t     flags;
    uint32_t     width, height;
+   uint32_t     last_swap;
 
    enum dri3_buffer_type        buffer_type;
 };
@@ -184,6 +185,7 @@ struct dri3_drawable {
    struct dri3_buffer *buffers[DRI3_NUM_BUFFERS];
    int cur_back;
    int num_back;
+   uint32_t swap_count;
 
    uint32_t *stamp;
 
diff --git a/src/glx/glx_pbuffer.c b/src/glx/glx_pbuffer.c
index 978730c..afb4206 100644
--- a/src/glx/glx_pbuffer.c
+++ b/src/glx/glx_pbuffer.c
@@ -373,6 +373,14 @@ GetDrawableAttribute(Display * dpy, GLXDrawable drawable,
             if (!pdraw->textureFormat)
                pdraw->textureFormat =
                   determineTextureFormat((const int *) data, num_attributes);
+
+            if (attribute == GLX_BACK_BUFFER_AGE_EXT) {
+               struct glx_screen *psc = pdraw->psc;
+
+               if (psc->driScreen->getBufferAge != NULL)
+                 *value = psc->driScreen->getBufferAge(pdraw);
+            }
+
          }
 #endif
 
diff --git a/src/glx/glxclient.h b/src/glx/glxclient.h
index a7118af..74c19c4 100644
--- a/src/glx/glxclient.h
+++ b/src/glx/glxclient.h
@@ -125,6 +125,7 @@ struct __GLXDRIscreenRec {
 		     int64_t *msc, int64_t *sbc);
    int (*setSwapInterval)(__GLXDRIdrawable *pdraw, int interval);
    int (*getSwapInterval)(__GLXDRIdrawable *pdraw);
+   int (*getBufferAge)(__GLXDRIdrawable *pdraw);
 };
 
 struct __GLXDRIdrawableRec
diff --git a/src/glx/glxextensions.c b/src/glx/glxextensions.c
index f186c13..ac1b4a7 100644
--- a/src/glx/glxextensions.c
+++ b/src/glx/glxextensions.c
@@ -103,6 +103,7 @@ static const struct extension_info known_glx_extensions[] = {
    { GLX(SGIX_visual_select_group),    VER(0,0), Y, Y, N, N },
    { GLX(EXT_texture_from_pixmap),     VER(0,0), Y, N, N, N },
    { GLX(INTEL_swap_event),            VER(0,0), Y, N, N, N },
+   { GLX(EXT_buffer_age),              VER(0,0), Y, N, Y, Y },
    { NULL }
 };
 
diff --git a/src/glx/glxextensions.h b/src/glx/glxextensions.h
index 8436a94..37e4ccc 100644
--- a/src/glx/glxextensions.h
+++ b/src/glx/glxextensions.h
@@ -66,6 +66,7 @@ enum
    SGIX_visual_select_group_bit,
    EXT_texture_from_pixmap_bit,
    INTEL_swap_event_bit,
+   EXT_buffer_age_bit,
 };
 
 /* From the GLX perspective, the ARB and EXT extensions are identical.  Use a
-- 
1.8.5.3