[PATCH 4/5] glx: Implement GLX_PRESERVED_CONTENTS drawable attribute

[Adam Jackson]

We back pixmaps with pbuffers so they're never actually clobbered, so
we're really just recording the value passed in at create time so that
you get the same thing when you query.

Signed-off-by: Adam Jackson <ajax at redhat.com>
---
 glx/glxcmds.c     | 90 +++++++++++++++++++++++++++++++++----------------------
 glx/glxdrawable.h |  1 +
 2 files changed, 55 insertions(+), 36 deletions(-)

diff --git a/glx/glxcmds.c b/glx/glxcmds.c
index 192c73f..41313f2 100644
--- a/glx/glxcmds.c
+++ b/glx/glxcmds.c
@@ -1378,13 +1378,43 @@ __glXDisp_DestroyPixmap(__GLXclientState * cl, GLbyte * pc)
 }
 
 static int
+DoChangeDrawableAttributes(ClientPtr client, XID glxdrawable,
+                           int numAttribs, CARD32 *attribs)
+{
+    __GLXdrawable *pGlxDraw;
+    int i, err;
+
+    if (!validGlxDrawable(client, glxdrawable, GLX_DRAWABLE_ANY,
+                          DixSetAttrAccess, &pGlxDraw, &err))
+        return err;
+
+    for (i = 0; i < numAttribs; i++) {
+        switch (attribs[i * 2]) {
+        case GLX_EVENT_MASK:
+            /* All we do is to record the event mask so we can send it
+             * back when queried.  We never actually clobber the
+             * pbuffers, so we never need to send out the event. */
+            pGlxDraw->eventMask = attribs[i * 2 + 1];
+            break;
+        case GLX_PRESERVED_CONTENTS:
+            /* same deal */
+            pGlxDraw->preserved = attribs[i * 2 + 1];
+            break;
+        }
+    }
+
+    return Success;
+}
+
+static int
 DoCreatePbuffer(ClientPtr client, int screenNum, XID fbconfigId,
-                int width, int height, XID glxDrawableId)
+                int width, int height, XID glxDrawableId, int preserved)
 {
     __GLXconfig *config;
     __GLXscreen *pGlxScreen;
     PixmapPtr pPixmap;
     int err;
+    CARD32 attribs[2] = { GLX_PRESERVED_CONTENTS, preserved };
 
     LEGAL_NEW_RESOURCE(glxDrawableId, client);
 
@@ -1406,9 +1436,13 @@ DoCreatePbuffer(ClientPtr client, int screenNum, XID fbconfigId,
     if (!AddResource(pPixmap->drawable.id, RT_PIXMAP, pPixmap))
         return BadAlloc;
 
-    return DoCreateGLXDrawable(client, pGlxScreen, config, &pPixmap->drawable,
-                               glxDrawableId, glxDrawableId,
-                               GLX_DRAWABLE_PBUFFER);
+    err = DoCreateGLXDrawable(client, pGlxScreen, config, &pPixmap->drawable,
+                              glxDrawableId, glxDrawableId,
+                              GLX_DRAWABLE_PBUFFER);
+    if (err != Success)
+        return err;
+
+    return DoChangeDrawableAttributes(serverClient, glxDrawableId, 1, attribs);
 }
 
 int
@@ -1417,7 +1451,7 @@ __glXDisp_CreatePbuffer(__GLXclientState * cl, GLbyte * pc)
     ClientPtr client = cl->client;
     xGLXCreatePbufferReq *req = (xGLXCreatePbufferReq *) pc;
     CARD32 *attrs;
-    int width, height, i;
+    int i, width = 0, height = 0, preserved = 1;
 
     REQUEST_AT_LEAST_SIZE(xGLXCreatePbufferReq);
     if (req->numAttribs > (UINT32_MAX >> 3)) {
@@ -1427,8 +1461,6 @@ __glXDisp_CreatePbuffer(__GLXclientState * cl, GLbyte * pc)
     REQUEST_FIXED_SIZE(xGLXCreatePbufferReq, req->numAttribs << 3);
 
     attrs = (CARD32 *) (req + 1);
-    width = 0;
-    height = 0;
 
     for (i = 0; i < req->numAttribs; i++) {
         switch (attrs[i * 2]) {
@@ -1438,15 +1470,17 @@ __glXDisp_CreatePbuffer(__GLXclientState * cl, GLbyte * pc)
         case GLX_PBUFFER_HEIGHT:
             height = attrs[i * 2 + 1];
             break;
-        case GLX_LARGEST_PBUFFER:
         case GLX_PRESERVED_CONTENTS:
+            preserved = attrs[i * 2 + 1];
+            break;
+        case GLX_LARGEST_PBUFFER:
             /* FIXME: huh... */
             break;
         }
     }
 
     return DoCreatePbuffer(cl->client, req->screen, req->fbconfig,
-                           width, height, req->pbuffer);
+                           width, height, req->pbuffer, preserved);
 }
 
 int
@@ -1457,8 +1491,12 @@ __glXDisp_CreateGLXPbufferSGIX(__GLXclientState * cl, GLbyte * pc)
 
     REQUEST_AT_LEAST_SIZE(xGLXCreateGLXPbufferSGIXReq);
 
+    /*
+     * We should really handle attributes correctly, but this extension
+     * is so rare I have difficulty caring.
+     */
     return DoCreatePbuffer(cl->client, req->screen, req->fbconfig,
-                           req->width, req->height, req->pbuffer);
+                           req->width, req->height, req->pbuffer, 1);
 }
 
 int
@@ -1483,31 +1521,6 @@ __glXDisp_DestroyGLXPbufferSGIX(__GLXclientState * cl, GLbyte * pc)
     return DoDestroyDrawable(cl, req->pbuffer, GLX_DRAWABLE_PBUFFER);
 }
 
-static int
-DoChangeDrawableAttributes(ClientPtr client, XID glxdrawable,
-                           int numAttribs, CARD32 *attribs)
-{
-    __GLXdrawable *pGlxDraw;
-    int i, err;
-
-    if (!validGlxDrawable(client, glxdrawable, GLX_DRAWABLE_ANY,
-                          DixSetAttrAccess, &pGlxDraw, &err))
-        return err;
-
-    for (i = 0; i < numAttribs; i++) {
-        switch (attribs[i * 2]) {
-        case GLX_EVENT_MASK:
-            /* All we do is to record the event mask so we can send it
-             * back when queried.  We never actually clobber the
-             * pbuffers, so we never need to send out the event. */
-            pGlxDraw->eventMask = attribs[i * 2 + 1];
-            break;
-        }
-    }
-
-    return Success;
-}
-
 int
 __glXDisp_ChangeDrawableAttributes(__GLXclientState * cl, GLbyte * pc)
 {
@@ -1874,7 +1887,7 @@ DoGetDrawableAttributes(__GLXclientState * cl, XID drawId)
     ClientPtr client = cl->client;
     xGLXGetDrawableAttributesReply reply;
     __GLXdrawable *pGlxDraw;
-    CARD32 attributes[12];
+    CARD32 attributes[14];
     int numAttribs = 0, error;
 
     if (!validGlxDrawable(client, drawId, GLX_DRAWABLE_ANY,
@@ -1900,6 +1913,11 @@ DoGetDrawableAttributes(__GLXclientState * cl, XID drawId)
     attributes[10] = GLX_FBCONFIG_ID;
     attributes[11] = pGlxDraw->config->fbconfigID;
     numAttribs++;
+    if (pGlxDraw->type == GLX_DRAWABLE_PBUFFER) {
+        attributes[12] = GLX_PRESERVED_CONTENTS;
+        attributes[13] = pGlxDraw->preserved;
+        numAttribs++;
+    }
 
     reply = (xGLXGetDrawableAttributesReply) {
         .type = X_Reply,
diff --git a/glx/glxdrawable.h b/glx/glxdrawable.h
index 0076589..4cbf43d 100644
--- a/glx/glxdrawable.h
+++ b/glx/glxdrawable.h
@@ -72,6 +72,7 @@ struct __GLXdrawable {
      ** Event mask
      */
     unsigned long eventMask;
+    int preserved;
 };
 
 #endif                          /* !__GLX_drawable_h__ */
-- 
1.8.1.4