[PATCH] wined3d: Allow constant buffers to be forced to be write-mappable.

[Jan Sikorski]

Using a registry setting. Games sometimes use DEFAULT usage and no CPU
access combined with UpdateSubresource() for often-changing constants,
causing us to interrupt the render pass and transfer through a staging
buffer on each update. In such cases forcing the buffers to be mappable
greatly increases performance.

Signed-off-by: Jan Sikorski <jsikorski(a)codeweavers.com>
---
I'm not sure if that kind of change is desired upstream, but I think
it's pretty useful.
---
 dlls/wined3d/buffer.c          | 9 +++++++--
 dlls/wined3d/wined3d_main.c    | 5 +++++
 dlls/wined3d/wined3d_private.h | 1 +
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/dlls/wined3d/buffer.c b/dlls/wined3d/buffer.c
index da61f36af45..a42259a5ece 100644
--- a/dlls/wined3d/buffer.c
+++ b/dlls/wined3d/buffer.c
@@ -1139,6 +1139,7 @@ static HRESULT wined3d_buffer_init(struct wined3d_buffer *buffer, struct wined3d
 {
     const struct wined3d_format *format = wined3d_get_format(device->adapter, WINED3DFMT_R8_UNORM, desc->bind_flags);
     struct wined3d_resource *resource = &buffer->resource;
+    unsigned int access;
     HRESULT hr;
 
     TRACE("buffer %p, device %p, desc byte_width %u, usage %s, bind_flags %s, "
@@ -1164,8 +1165,12 @@ static HRESULT wined3d_buffer_init(struct wined3d_buffer *buffer, struct wined3d
         return E_INVALIDARG;
     }
 
+    access = desc->access;
+    if (desc->bind_flags & WINED3D_BIND_CONSTANT_BUFFER && wined3d_settings.write_mappable_cbuffers)
+        access |= WINED3D_RESOURCE_ACCESS_MAP_W;
+
     if (FAILED(hr = resource_init(resource, device, WINED3D_RTYPE_BUFFER, format,
-            WINED3D_MULTISAMPLE_NONE, 0, desc->usage, desc->bind_flags, desc->access,
+            WINED3D_MULTISAMPLE_NONE, 0, desc->usage, desc->bind_flags, access,
             desc->byte_width, 1, 1, desc->byte_width, parent, parent_ops, &buffer_resource_ops)))
     {
         WARN("Failed to initialize resource, hr %#x.\n", hr);
@@ -1179,7 +1184,7 @@ static HRESULT wined3d_buffer_init(struct wined3d_buffer *buffer, struct wined3d
             buffer, buffer->resource.size, buffer->resource.usage, buffer->resource.heap_memory);
 
     if (device->create_parms.flags & WINED3DCREATE_SOFTWARE_VERTEXPROCESSING
-            || wined3d_resource_access_is_managed(desc->access))
+            || wined3d_resource_access_is_managed(access))
     {
         /* SWvp and managed buffers always return the same pointer in buffer
          * maps and retain data in DISCARD maps. Keep a system memory copy of
diff --git a/dlls/wined3d/wined3d_main.c b/dlls/wined3d/wined3d_main.c
index 6e93b8dc683..a059598ec21 100644
--- a/dlls/wined3d/wined3d_main.c
+++ b/dlls/wined3d/wined3d_main.c
@@ -394,6 +394,11 @@ static BOOL wined3d_dll_init(HINSTANCE hInstDLL)
                 wined3d_settings.renderer = WINED3D_RENDERER_NO3D;
             }
         }
+        if (!get_config_key_dword(hkey, appkey, "WriteMappableConstantBuffers", &tmpvalue) && tmpvalue)
+        {
+            TRACE("Forcing all constant buffers to be write-mappable.\n");
+            wined3d_settings.write_mappable_cbuffers = TRUE;
+        }
     }
 
     if (appkey) RegCloseKey( appkey );
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index 86c053df0db..9357223cb97 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -482,6 +482,7 @@ struct wined3d_settings
     unsigned int max_sm_cs;
     enum wined3d_renderer renderer;
     enum wined3d_shader_backend shader_backend;
+    BOOL write_mappable_cbuffers;
 };
 
 extern struct wined3d_settings wined3d_settings DECLSPEC_HIDDEN;
-- 
2.30.2

[Henri Verbeet]

On Mon, 6 Sept 2021 at 15:36, Jan Sikorski <jsikorski(a)codeweavers.com> wrote:
> diff --git a/dlls/wined3d/wined3d_main.c b/dlls/wined3d/wined3d_main.c
> index 6e93b8dc683..a059598ec21 100644
> --- a/dlls/wined3d/wined3d_main.c
> +++ b/dlls/wined3d/wined3d_main.c
> @@ -394,6 +394,11 @@ static BOOL wined3d_dll_init(HINSTANCE hInstDLL)
>                  wined3d_settings.renderer = WINED3D_RENDERER_NO3D;
>              }
>          }
> +        if (!get_config_key_dword(hkey, appkey, "WriteMappableConstantBuffers", &tmpvalue) && tmpvalue)
> +        {
> +            TRACE("Forcing all constant buffers to be write-mappable.\n");
> +            wined3d_settings.write_mappable_cbuffers = TRUE;
> +        }
>      }

We tend to use the same name for the registry setting as for the field
name in the wined3d_settings structure for new settings. (So in this
case that would then be "write_mappable_cbuffers" for the registry
setting as well, or perhaps e.g. "cb_access_map_w" for both.)