From 379ae701c04046661a092cacd7263ca97101f51b Mon Sep 17 00:00:00 2001
From: Zebediah Figura <zfigura@codeweavers.com>
Date: Thu, 22 Dec 2022 12:33:15 -0600
Subject: [PATCH] d3d8: Filter out redundant buffer discards.

I was unable to write tests for this; it seems it doesn't consistently work on
Windows. However, Rayman 3 seems to rely on it; it maps the same buffer twice
immediately after creation, with DISCARD flags on both maps, and expects the
same address to be returned.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53752
---
 dlls/d3d8/buffer.c       | 10 ++++++++++
 dlls/d3d8/d3d8_private.h |  2 ++
 dlls/d3d8/device.c       | 28 ++++++++++++++++++++++++++--
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/dlls/d3d8/buffer.c b/dlls/d3d8/buffer.c
index 2b0f0a41888..23dcf05044c 100644
--- a/dlls/d3d8/buffer.c
+++ b/dlls/d3d8/buffer.c
@@ -192,6 +192,11 @@ static HRESULT WINAPI d3d8_vertexbuffer_Lock(IDirect3DVertexBuffer8 *iface, UINT
     TRACE("iface %p, offset %u, size %u, data %p, flags %#lx.\n",
             iface, offset, size, data, flags);
 
+    if (buffer->discarded)
+        flags &= ~D3DLOCK_DISCARD;
+    if (flags & D3DLOCK_DISCARD)
+        buffer->discarded = true;
+
     wined3d_box.left = offset;
     wined3d_box.right = offset + size;
     wined3d_resource = wined3d_buffer_get_resource(buffer->wined3d_buffer);
@@ -508,6 +513,11 @@ static HRESULT WINAPI d3d8_indexbuffer_Lock(IDirect3DIndexBuffer8 *iface, UINT o
     TRACE("iface %p, offset %u, size %u, data %p, flags %#lx.\n",
             iface, offset, size, data, flags);
 
+    if (buffer->discarded)
+        flags &= ~D3DLOCK_DISCARD;
+    if (flags & D3DLOCK_DISCARD)
+        buffer->discarded = true;
+
     wined3d_box.left = offset;
     wined3d_box.right = offset + size;
     wined3d_resource = wined3d_buffer_get_resource(buffer->wined3d_buffer);
diff --git a/dlls/d3d8/d3d8_private.h b/dlls/d3d8/d3d8_private.h
index 340f4f2d07d..dda85062dea 100644
--- a/dlls/d3d8/d3d8_private.h
+++ b/dlls/d3d8/d3d8_private.h
@@ -217,6 +217,7 @@ struct d3d8_vertexbuffer
     IDirect3DDevice8 *parent_device;
     struct wined3d_buffer *draw_buffer;
     DWORD fvf, usage;
+    bool discarded;
 };
 
 HRESULT vertexbuffer_init(struct d3d8_vertexbuffer *buffer, struct d3d8_device *device,
@@ -232,6 +233,7 @@ struct d3d8_indexbuffer
     enum wined3d_format_id format;
     DWORD usage;
     bool sysmem;
+    bool discarded;
 };
 
 HRESULT indexbuffer_init(struct d3d8_indexbuffer *buffer, struct d3d8_device *device,
diff --git a/dlls/d3d8/device.c b/dlls/d3d8/device.c
index fb7e25a6bc1..539dd7a89b9 100644
--- a/dlls/d3d8/device.c
+++ b/dlls/d3d8/device.c
@@ -2516,7 +2516,8 @@ static HRESULT WINAPI d3d8_device_DrawPrimitive(IDirect3DDevice8 *iface,
         D3DPRIMITIVETYPE primitive_type, UINT start_vertex, UINT primitive_count)
 {
     struct d3d8_device *device = impl_from_IDirect3DDevice8(iface);
-    unsigned int vertex_count;
+    struct d3d8_vertexbuffer *vb;
+    unsigned int vertex_count, i;
 
     TRACE("iface %p, primitive_type %#x, start_vertex %u, primitive_count %u.\n",
             iface, primitive_type, start_vertex, primitive_count);
@@ -2529,6 +2530,16 @@ static HRESULT WINAPI d3d8_device_DrawPrimitive(IDirect3DDevice8 *iface,
             wined3d_primitive_type_from_d3d(primitive_type), 0);
     wined3d_device_apply_stateblock(device->wined3d_device, device->state);
     wined3d_device_context_draw(device->immediate_context, start_vertex, vertex_count, 0, 0);
+
+    for (i = 0; i < ARRAY_SIZE(device->stateblock_state->streams); ++i)
+    {
+        if (device->stateblock_state->streams[i].buffer)
+        {
+            vb = wined3d_buffer_get_parent(device->stateblock_state->streams[i].buffer);
+            vb->discarded = false;
+        }
+    }
+
     wined3d_mutex_unlock();
 
     return D3D_OK;
@@ -2539,7 +2550,9 @@ static HRESULT WINAPI d3d8_device_DrawIndexedPrimitive(IDirect3DDevice8 *iface,
         UINT start_idx, UINT primitive_count)
 {
     struct d3d8_device *device = impl_from_IDirect3DDevice8(iface);
-    unsigned int index_count;
+    struct d3d8_vertexbuffer *vb;
+    struct d3d8_indexbuffer *ib;
+    unsigned int index_count, i;
     int base_vertex_index;
     HRESULT hr;
 
@@ -2567,6 +2580,17 @@ static HRESULT WINAPI d3d8_device_DrawIndexedPrimitive(IDirect3DDevice8 *iface,
     }
     wined3d_device_context_draw_indexed(device->immediate_context, base_vertex_index, start_idx, index_count, 0, 0);
 
+    ib = wined3d_buffer_get_parent(device->stateblock_state->index_buffer);
+    ib->discarded = false;
+    for (i = 0; i < ARRAY_SIZE(device->stateblock_state->streams); ++i)
+    {
+        if (device->stateblock_state->streams[i].buffer)
+        {
+            vb = wined3d_buffer_get_parent(device->stateblock_state->streams[i].buffer);
+            vb->discarded = false;
+        }
+    }
+
     wined3d_mutex_unlock();
 
     return D3D_OK;