[PATCH 6/9] wined3d: Add a memory_colour_fill for clearing the entire level to zero.

[Stefan Dösinger]

Signed-off-by: Stefan Dösinger 
---
 dlls/wined3d/resource.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index 8c3ca59bedc..9dab928dbc0 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -634,6 +634,16 @@ void wined3d_resource_memory_colour_fill(struct wined3d_resource *resource,
         wined3d_texture_get_level_box(texture_from_resource(resource), level, &level_box);
     }

+    /* Fast and simple path for setting everything to zero. The C library's memset is
+     * more sophisticated than our code below. Also this works for block formats, which
+     * we still need to zero-initialize for newly created resources. */
+    if (!colour->r && !colour->g && !colour->b && !colour->a &&
+            !memcmp(box, &level_box, sizeof(*box)))
+    {
+        memset(map->data, 0, map->slice_pitch * box->back);
+        return;
+    }
+
     w = min(box->right, level_box.right) - min(box->left, level_box.right);
     h = min(box->bottom, level_box.bottom) - min(box->top, level_box.bottom);
     if (resource->type != WINED3D_RTYPE_TEXTURE_3D)