Henri Verbeet : wined3d: Clarify WINED3DUSAGE_WRITEONLY a bit.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 63f2b65141ada3e5c5ba55d606c0f2bf6dc7c626
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=63f2b65141ada3e5c5ba55d606...

Author: Henri Verbeet <hverbeet(a)codeweavers.com>
Date:   Mon Jul 14 10:04:23 2014 +0200

wined3d: Clarify WINED3DUSAGE_WRITEONLY a bit.

---

 dlls/wined3d/resource.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index caec580..934cabc 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -59,6 +59,12 @@ static void resource_check_usage(DWORD usage)
             | WINED3DUSAGE_OVERLAY
             | WINED3DUSAGE_TEXTURE;
 
+    /* WINED3DUSAGE_WRITEONLY is supposed to result in write-combined mappings
+     * being returned. OpenGL doesn't give us explicit control over that, but
+     * the hints and access flags we set for typical access patterns on
+     * dynamic resources should in theory have the same effect on the OpenGL
+     * driver. */
+
     if (usage & ~handled)
         FIXME("Unhandled usage flags %#x.\n", usage & ~handled);
     if ((usage & (WINED3DUSAGE_DYNAMIC | WINED3DUSAGE_WRITEONLY)) == WINED3DUSAGE_DYNAMIC)