Zebediah Figura : ddraw: Use system memory for version 4 vertex buffers.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 498f0f115db61b7259dde738aef6804d4c062fcd
URL:    https://gitlab.winehq.org/wine/wine/-/commit/498f0f115db61b7259dde738aef6804...

Author: Zebediah Figura <zfigura(a)codeweavers.com>
Date:   Fri Jan 13 20:00:11 2023 -0600

ddraw: Use system memory for version 4 vertex buffers.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=44863

---

 dlls/ddraw/ddraw_private.h |  1 +
 dlls/ddraw/device.c        |  4 ++--
 dlls/ddraw/vertexbuffer.c  | 15 ++++++++++++++-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/dlls/ddraw/ddraw_private.h b/dlls/ddraw/ddraw_private.h
index 1f0c94a9c6e..7d08ffea361 100644
--- a/dlls/ddraw/ddraw_private.h
+++ b/dlls/ddraw/ddraw_private.h
@@ -595,6 +595,7 @@ struct d3d_vertex_buffer
     DWORD                size;
     BOOL                 dynamic;
     bool discarded;
+    bool sysmem;
 };
 
 HRESULT d3d_vertex_buffer_create(struct d3d_vertex_buffer **buffer, struct ddraw *ddraw,
diff --git a/dlls/ddraw/device.c b/dlls/ddraw/device.c
index f64db3aa633..a744d361bd7 100644
--- a/dlls/ddraw/device.c
+++ b/dlls/ddraw/device.c
@@ -4128,7 +4128,7 @@ static HRESULT d3d_device7_DrawPrimitiveVB(IDirect3DDevice7 *iface, D3DPRIMITIVE
 
     stride = get_flexible_vertex_size(vb_impl->fvf);
 
-    if (vb_impl->Caps & D3DVBCAPS_SYSTEMMEMORY)
+    if (vb_impl->sysmem)
     {
         TRACE("Drawing from D3DVBCAPS_SYSTEMMEMORY vertex buffer, forwarding to DrawPrimitive().\n");
         wined3d_mutex_lock();
@@ -4246,7 +4246,7 @@ static HRESULT d3d_device7_DrawIndexedPrimitiveVB(IDirect3DDevice7 *iface,
 
     vb_impl->discarded = false;
 
-    if (vb_impl->Caps & D3DVBCAPS_SYSTEMMEMORY)
+    if (vb_impl->sysmem)
     {
         TRACE("Drawing from D3DVBCAPS_SYSTEMMEMORY vertex buffer, forwarding to DrawIndexedPrimitive().\n");
         wined3d_mutex_lock();
diff --git a/dlls/ddraw/vertexbuffer.c b/dlls/ddraw/vertexbuffer.c
index 73cf0a37991..c02d7e6e354 100644
--- a/dlls/ddraw/vertexbuffer.c
+++ b/dlls/ddraw/vertexbuffer.c
@@ -120,7 +120,7 @@ static HRESULT d3d_vertex_buffer_create_wined3d_buffer(struct d3d_vertex_buffer
     if (dynamic)
         desc.usage |= WINED3DUSAGE_DYNAMIC;
     desc.bind_flags = WINED3D_BIND_VERTEX_BUFFER;
-    if (buffer->Caps & D3DVBCAPS_SYSTEMMEMORY)
+    if (buffer->sysmem)
         desc.access = WINED3D_RESOURCE_ACCESS_CPU | WINED3D_RESOURCE_ACCESS_MAP_R | WINED3D_RESOURCE_ACCESS_MAP_W;
     else
         desc.access = WINED3D_RESOURCE_ACCESS_GPU | WINED3D_RESOURCE_ACCESS_MAP_R | WINED3D_RESOURCE_ACCESS_MAP_W;
@@ -466,6 +466,19 @@ HRESULT d3d_vertex_buffer_create(struct d3d_vertex_buffer **vertex_buf,
     buffer->fvf = desc->dwFVF;
     buffer->size = get_flexible_vertex_size(desc->dwFVF) * desc->dwNumVertices;
 
+    /* ddraw4 vertex buffers ignore DISCARD and NOOVERWRITE, even on
+     * pretransformed geometry, which means that a GPU-based buffer cannot
+     * perform well.
+     *
+     * While at least one contemporaneous card (Geforce 4) does seem to show a
+     * difference in its performance characteristics based on whether
+     * D3DVBCAPS_SYSTEMMEMORY is set, it also doesn't *improve* performance to
+     * use a non-SYSTEMMEMORY buffer with ddraw4. For wined3d it should always
+     * be better to use sysmem.
+     *
+     * This improves performance in Prince of Persia 3D. */
+    buffer->sysmem = ((buffer->Caps & D3DVBCAPS_SYSTEMMEMORY) || buffer->version < 7);
+
     wined3d_mutex_lock();
 
     if (FAILED(hr = d3d_vertex_buffer_create_wined3d_buffer(buffer, FALSE, &buffer->wined3d_buffer)))