2 files changed, 47 insertions, 1 deletions

diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index cd176dec27..2d90a949c3 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -10,6 +10,7 @@
 #include <memory>
 #include <numeric>
 #include <stdexcept>
+#include <utility>
 #include <vector>
 #include <fmt/ranges.h>
 
@@ -180,6 +181,7 @@ void BufferCache<P>::WriteMemory(DAddr device_addr, u64 size) {
         gpu_modified_ranges.Subtract(device_addr, size);
     }
     memory_tracker.MarkRegionAsCpuModified(device_addr, size);
+    MarkVertexBuffersStale(device_addr, size);
 }
 
 template <class P>
@@ -265,6 +267,7 @@ bool BufferCache<P>::DMACopy(GPUVAddr src_address, GPUVAddr dest_address, u64 am
     }
 
     ClearDownload(*cpu_dest_address, amount);
+    MarkVertexBuffersStale(*cpu_dest_address, amount);
 
     BufferId buffer_a;
     BufferId buffer_b;
@@ -408,7 +411,8 @@ void BufferCache<P>::BindGraphicsUniformBuffer(size_t stage, u32 index, GPUVAddr
 template <class P>
 void BufferCache<P>::DisableGraphicsUniformBuffer(size_t stage, u32 index) {
     auto& current = channel_state->uniform_buffers[stage][index];
-    if (current.device_addr == 0 && current.size == 0 && !current.buffer_id) [[likely]] {
+    if (current.device_addr == 0 && current.size == 0 && current.buffer_id == NULL_BUFFER_ID)
+        [[likely]] {
         return;
     }
     current = NULL_BINDING;
@@ -893,7 +897,39 @@ void BufferCache<P>::UpdateVertexBufferSlot(u32 index, const Binding& binding) {
 }
 
 template <class P>
+void BufferCache<P>::MarkVertexBuffersStale(DAddr device_addr, u64 size) {
+    if constexpr (requires { runtime.IsVertexRepacked(u32{}); }) {
+        u32 mask = enabled_vertex_buffers_mask;
+        while (mask != 0) {
+            const u32 index = std::countr_zero(mask);
+            mask &= mask - 1;
+            const Binding& binding = v_buffer[index];
+            if (device_addr < binding.device_addr + binding.size &&
+                binding.device_addr < device_addr + size) {
+                stale_vertex_buffers_mask |= 1U << index;
+            }
+        }
+    }
+}
+
+template <class P>
+void BufferCache<P>::RefreshRepackedVertexBuffers() {
+    if constexpr (requires { runtime.IsVertexRepacked(u32{}); }) {
+        u32 mask = std::exchange(stale_vertex_buffers_mask, 0) & enabled_vertex_buffers_mask;
+        auto& flags = maxwell3d->dirty.flags;
+        while (mask != 0) {
+            const u32 index = std::countr_zero(mask);
+            mask &= mask - 1;
+            if (runtime.IsVertexRepacked(index)) {
+                flags[Dirty::VertexBuffer0 + index] = true;
+            }
+        }
+    }
+}
+
+template <class P>
 void BufferCache<P>::BindHostVertexBuffers() {
+    RefreshRepackedVertexBuffers();
 
 #ifdef __ANDROID__
     const bool use_optimized_vertex_buffers = Settings::values.use_optimized_vertex_buffers.GetValue();
@@ -1655,6 +1691,7 @@ void BufferCache<P>::MarkWrittenBuffer(BufferId buffer_id, DAddr device_addr, u3
         }
     }
     memory_tracker.MarkRegionAsGpuModified(device_addr, size);
+    MarkVertexBuffersStale(device_addr, size);
     gpu_modified_ranges.Add(device_addr, size);
     if (DownloadsAtFence(device_addr, size)) {
         uncommitted_gpu_modified_ranges.Add(device_addr, size);
@@ -2205,6 +2242,7 @@ void BufferCache<P>::InlineMemoryImplementation(DAddr dest_address, size_t copy_
                                                 std::span<const u8> inlined_buffer) {
     ClearDownload(dest_address, copy_size);
     gpu_modified_ranges.Subtract(dest_address, copy_size);
+    MarkVertexBuffersStale(dest_address, copy_size);
 
     BufferId buffer_id = FindBuffer(dest_address, static_cast<u32>(copy_size), false);
     auto& buffer = slot_buffers[buffer_id];
diff --git a/src/video_core/buffer_cache/buffer_cache_base.h b/src/video_core/buffer_cache/buffer_cache_base.h
index d1199ef517..86c05c8f22 100644
--- a/src/video_core/buffer_cache/buffer_cache_base.h
+++ b/src/video_core/buffer_cache/buffer_cache_base.h
@@ -526,6 +526,13 @@ private:
 
     void UpdateVertexBufferSlot(u32 index, const Binding& binding);
 
+    /// Flags the vertex buffers overlapping a written range so host copies derived from them are
+    /// rebuilt.
+    void MarkVertexBuffersStale(DAddr device_addr, u64 size);
+
+    /// Re-dirties repacked vertex buffers whose source data was written since they were bound.
+    void RefreshRepackedVertexBuffers();
+
     void ClearDownload(DAddr base_addr, u64 size);
 
     void InlineMemoryImplementation(DAddr dest_address, size_t copy_size,
@@ -546,6 +553,7 @@ private:
     u32 last_index_count = 0;
 
     u32 enabled_vertex_buffers_mask = 0;
+    u32 stale_vertex_buffers_mask = 0;
     u64 vertex_buffers_serial = 0;
     std::array<Binding, 32> v_buffer{};