Implement GLX_MESA_copy_sub_buffer.

GL/glx/glxcmds.c

@@ -1605,8 +1605,13 @@ int __glXReleaseTexImageEXT(__GLXclientState *cl, GLbyte *pc)
 int __glXCopySubBufferMESA(__GLXclientState *cl, GLbyte *pc)
 {
     xGLXVendorPrivateReq *req = (xGLXVendorPrivateReq *) pc;
+    GLXContextTag         tag = req->contextTag;
+    __GLXcontext         *glxc = NULL;
+    __GLXdrawable        *pGlxDraw;
+    __GLXpixmap          *pPixmap;
     ClientPtr		  client = cl->client;
     GLXDrawable		  drawId;
+    int                   error;
     int                   x, y, width, height;
 
     (void) client;
@@ -1620,7 +1625,40 @@ int __glXCopySubBufferMESA(__GLXclientState *cl, GLbyte *pc)
     width  = *((INT32 *)  (pc + 12));
     height = *((INT32 *)  (pc + 16));
 
-    return BadRequest;
+    if (tag) {
+	glxc = __glXLookupContextByTag(cl, tag);
+	if (!glxc) {
+	    return __glXError(GLXBadContextTag);
+	}
+	/*
+	** The calling thread is swapping its current drawable.  In this case,
+	** glxSwapBuffers is in both GL and X streams, in terms of
+	** sequentiality.
+	*/
+	if (__glXForceCurrent(cl, tag, &error)) {
+	    /*
+	    ** Do whatever is needed to make sure that all preceding requests
+	    ** in both streams are completed before the swap is executed.
+	    */
+	    CALL_Finish( GET_DISPATCH(), () );
+	    __GLX_NOTE_FLUSHED_CMDS(glxc);
+	} else {
+	    return error;
+	}
+    }
+
+    error = GetDrawableOrPixmap(glxc, drawId, &pGlxDraw, &pPixmap, client);
+    if (error != Success)
+	return error;
+
+    if (pGlxDraw == NULL ||
+	pGlxDraw->type != DRAWABLE_WINDOW ||
+	pGlxDraw->copySubBuffer == NULL)
+	return __glXError(GLXBadDrawable);
+
+    (*pGlxDraw->copySubBuffer)(pGlxDraw, x, y, width, height);
+
+    return Success;
 }
 
 /*

GL/glx/glxdrawable.h

@@ -58,6 +58,8 @@ struct __GLXdrawable {
     void (*destroy)(__GLXdrawable *private);
     GLboolean (*resize)(__GLXdrawable *private);
     GLboolean (*swapBuffers)(__GLXdrawable *);
+    void      (*copySubBuffer)(__GLXdrawable *drawable,
+			       int x, int y, int w, int h);
 
     /*
     ** list of drawable private structs

GL/glx/glxdri.c

@@ -112,12 +112,28 @@ struct __GLXDRIdrawable {
  *            months ago. :(
  * 20050727 - Gut all the old interfaces.  This breaks compatability with
  *            any DRI driver built to any previous version.
+ * 20060314 - Added support for GLX_MESA_copy_sub_buffer.
  */
+
 #define INTERNAL_VERSION 20050727
 
 static const char CREATE_NEW_SCREEN_FUNC[] =
     "__driCreateNewScreen_" STRINGIFY (INTERNAL_VERSION);
 
+/* The DRI driver entry point version wasn't bumped when the
+ * copySubBuffer functionality was added to the DRI drivers, but the
+ * functionality is still conditional on the value of the
+ * internal_api_version passed to __driCreateNewScreen.  However, the
+ * screen constructor doesn't fail for a DRI driver that's older than
+ * the passed in version number, so there's no way we can know for
+ * sure that we can actually use the copySubBuffer functionality.  But
+ * since the earliest (and at this point only) released mesa version
+ * (6.5) that uses the 20050727 entry point does have copySubBuffer,
+ * we'll just settle for that.  We still have to pass in a higher to
+ * the screen constructor to enable the functionality.
+ */
+#define COPY_SUB_BUFFER_INTERNAL_VERSION 20060314
+
 static void
 __glXDRIleaveServer(void)
 {
@@ -177,6 +193,27 @@ __glXDRIdrawableSwapBuffers(__GLXdrawable *basePrivate)
     return TRUE;
 }
 
+static void
+__glXDRIdrawableCopySubBuffer(__GLXdrawable *basePrivate,
+			       int x, int y, int w, int h)
+{
+    __GLXDRIdrawable *private = (__GLXDRIdrawable *) basePrivate;
+    __GLXDRIscreen *screen;
+
+    /* FIXME: We're jumping through hoops here to get the DRIdrawable
+     * which the dri driver tries to keep to it self...  cf. FIXME in
+     * createDrawable. */
+
+    screen = (__GLXDRIscreen *) __glXgetActiveScreen(private->base.pDraw->pScreen->myNum);
+    private->driDrawable = (screen->driScreen.getDrawable)(NULL,
+							   private->base.drawId,
+							   screen->driScreen.private);
+
+    (*private->driDrawable->copySubBuffer)(NULL,
+					   private->driDrawable->private,
+					   x, y, w, h);
+}
+
 static void
 __glXDRIcontextDestroy(__GLXcontext *baseContext)
 {
@@ -474,10 +511,11 @@ __glXDRIscreenCreateDrawable(__GLXscreen *screen,
 	return NULL;
     }
 
-    private->base.destroy     = __glXDRIdrawableDestroy;
-    private->base.resize      = __glXDRIdrawableResize;
-    private->base.swapBuffers = __glXDRIdrawableSwapBuffers;
-    
+    private->base.destroy       = __glXDRIdrawableDestroy;
+    private->base.resize        = __glXDRIdrawableResize;
+    private->base.swapBuffers   = __glXDRIdrawableSwapBuffers;
+    private->base.copySubBuffer = __glXDRIdrawableCopySubBuffer;
+
 #if 0
     /* FIXME: It would only be natural that we called
      * driScreen->createNewDrawable here but the DRI drivers manage
@@ -770,7 +808,7 @@ __glXDRIscreenProbe(ScreenPtr pScreen)
     __DRIframebuffer  framebuffer;
     int   fd = -1;
     int   status;
-    int api_ver = INTERNAL_VERSION;
+    int api_ver = COPY_SUB_BUFFER_INTERNAL_VERSION;
     drm_magic_t magic;
     drmVersionPtr version;
     char *driverName;