[PATCH 3/3] wined3d: Introduce WINED3D_LOCATION_CLEARED and use it for the initial state of buffers.

[Zebediah Figura]

The practical effect of this is to defer clearing buffers until they are used.
Under normal circumstances the buffer will be initially discarded, in which
case we need not clear it at all, and may even avoid ever allocating sysmem.

Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
---
 dlls/wined3d/buffer.c          | 31 +++++++++++++++++++++++--------
 dlls/wined3d/utils.c           |  1 +
 dlls/wined3d/wined3d_private.h |  1 +
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/dlls/wined3d/buffer.c b/dlls/wined3d/buffer.c
index abbef0fac41..2f3b5fd316e 100644
--- a/dlls/wined3d/buffer.c
+++ b/dlls/wined3d/buffer.c
@@ -607,13 +607,28 @@ BOOL wined3d_buffer_load_location(struct wined3d_buffer *buffer,
     switch (location)
     {
         case WINED3D_LOCATION_SYSMEM:
-            range.offset = 0;
-            range.size = buffer->resource.size;
-            buffer->buffer_ops->buffer_download_ranges(buffer, context,
-                    buffer->resource.heap_memory, 0, 1, &range);
+            if (buffer->locations & WINED3D_LOCATION_CLEARED)
+            {
+                memset(buffer->resource.heap_memory, 0, buffer->resource.size);
+            }
+            else
+            {
+                range.offset = 0;
+                range.size = buffer->resource.size;
+                buffer->buffer_ops->buffer_download_ranges(buffer, context,
+                        buffer->resource.heap_memory, 0, 1, &range);
+            }
             break;
 
         case WINED3D_LOCATION_BUFFER:
+            if (buffer->locations & WINED3D_LOCATION_CLEARED)
+            {
+                /* FIXME: Clear the buffer on the GPU if possible. */
+                if (!wined3d_buffer_prepare_location(buffer, context, WINED3D_LOCATION_SYSMEM))
+                    return FALSE;
+                memset(buffer->resource.heap_memory, 0, buffer->resource.size);
+            }
+
             if (!buffer->conversion_map)
                 buffer->buffer_ops->buffer_upload_ranges(buffer, context,
                         buffer->resource.heap_memory, 0, buffer->modified_areas, buffer->maps);
@@ -650,7 +665,7 @@ DWORD wined3d_buffer_get_memory(struct wined3d_buffer *buffer, struct wined3d_co
     TRACE("buffer %p, context %p, data %p, locations %s.\n",
             buffer, context, data, wined3d_debug_location(locations));
 
-    if (locations & WINED3D_LOCATION_DISCARDED)
+    if (locations & (WINED3D_LOCATION_DISCARDED | WINED3D_LOCATION_CLEARED))
     {
         locations = ((buffer->flags & WINED3D_BUFFER_USE_BO) ? WINED3D_LOCATION_BUFFER : WINED3D_LOCATION_SYSMEM);
         if (!wined3d_buffer_load_location(buffer, context, locations))
@@ -949,7 +964,7 @@ static HRESULT buffer_resource_sub_resource_map(struct wined3d_resource *resourc
         }
 
         if (flags & WINED3D_MAP_WRITE)
-            wined3d_buffer_invalidate_range(buffer, WINED3D_LOCATION_BUFFER, dirty_offset, dirty_size);
+            wined3d_buffer_invalidate_range(buffer, ~WINED3D_LOCATION_SYSMEM, dirty_offset, dirty_size);
     }
     else
     {
@@ -971,7 +986,7 @@ static HRESULT buffer_resource_sub_resource_map(struct wined3d_resource *resourc
 
         if (flags & WINED3D_MAP_WRITE)
         {
-            wined3d_buffer_invalidate_location(buffer, WINED3D_LOCATION_SYSMEM);
+            wined3d_buffer_invalidate_location(buffer, ~WINED3D_LOCATION_BUFFER);
             buffer_invalidate_bo_range(buffer, dirty_offset, dirty_size);
         }
 
@@ -1241,7 +1256,7 @@ static HRESULT wined3d_buffer_init(struct wined3d_buffer *buffer, struct wined3d
     }
     buffer->buffer_ops = buffer_ops;
     buffer->structure_byte_stride = desc->structure_byte_stride;
-    buffer->locations = data ? WINED3D_LOCATION_DISCARDED : WINED3D_LOCATION_SYSMEM;
+    buffer->locations = WINED3D_LOCATION_CLEARED;
 
     TRACE("buffer %p, size %#x, usage %#x, memory @ %p.\n",
             buffer, buffer->resource.size, buffer->resource.usage, buffer->resource.heap_memory);
diff --git a/dlls/wined3d/utils.c b/dlls/wined3d/utils.c
index e50d42ead92..bf9ae11ea13 100644
--- a/dlls/wined3d/utils.c
+++ b/dlls/wined3d/utils.c
@@ -6864,6 +6864,7 @@ const char *wined3d_debug_location(DWORD location)
 #define LOCATION_TO_STR(x) if (location & x) { debug_append(&buffer, #x, " | "); location &= ~x; }
     LOCATION_TO_STR(WINED3D_LOCATION_DISCARDED);
     LOCATION_TO_STR(WINED3D_LOCATION_SYSMEM);
+    LOCATION_TO_STR(WINED3D_LOCATION_CLEARED);
     LOCATION_TO_STR(WINED3D_LOCATION_BUFFER);
     LOCATION_TO_STR(WINED3D_LOCATION_TEXTURE_RGB);
     LOCATION_TO_STR(WINED3D_LOCATION_TEXTURE_SRGB);
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index e28fc3b880d..1b3a13024f9 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -4316,6 +4316,7 @@ void wined3d_resource_update_draw_binding(struct wined3d_resource *resource) DEC
 
 #define WINED3D_LOCATION_DISCARDED      0x00000001
 #define WINED3D_LOCATION_SYSMEM         0x00000002
+#define WINED3D_LOCATION_CLEARED        0x00000004
 #define WINED3D_LOCATION_BUFFER         0x00000008
 #define WINED3D_LOCATION_TEXTURE_RGB    0x00000010
 #define WINED3D_LOCATION_TEXTURE_SRGB   0x00000020
-- 
2.34.1