From 07f7ccdc9637265312ecbf7be95c9621e0decd9d Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Sun, 16 Feb 2025 13:53:46 +0100
Subject: [PATCH] [dxvk,d3d11] Fix draw buffer tracking for DrawAuto

Not like anybody uses this feature, but we need to both check for
hazards and make sure the SO counter actually gets tracked. Use
the existing draw buffer mechanism for this.
---
 src/d3d11/d3d11_context.cpp | 16 ++++++++++++++--
 src/dxvk/dxvk_context.cpp   | 16 +++++++++-------
 src/dxvk/dxvk_context.h     |  8 ++++----
 3 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/src/d3d11/d3d11_context.cpp b/src/d3d11/d3d11_context.cpp
index bdbbf25a6..0868ab9ed 100644
--- a/src/d3d11/d3d11_context.cpp
+++ b/src/d3d11/d3d11_context.cpp
@@ -1009,10 +1009,22 @@ namespace dxvk {
     if (!ctrBuf.defined())
       return;
 
-    EmitCs([=] (DxvkContext* ctx) {
-      ctx->drawIndirectXfb(ctrBuf,
+    // We bind the SO counter as an indirect count buffer,
+    // so reset any tracking we may have been doing here.
+    m_state.id.reset();
+
+    EmitCs([=] (DxvkContext* ctx) mutable {
+      ctx->bindDrawBuffers(DxvkBufferSlice(),
+        Forwarder::move(ctrBuf));
+
+      ctx->drawIndirectXfb(0u,
         vtxBuf.buffer()->getXfbVertexStride(),
         vtxBuf.offset());
+
+      // Reset draw buffer right away so we don't
+      // keep the SO counter alive indefinitely
+      ctx->bindDrawBuffers(DxvkBufferSlice(),
+        DxvkBufferSlice());
     });
   }
 
diff --git a/src/dxvk/dxvk_context.cpp b/src/dxvk/dxvk_context.cpp
index f2d1d6e3c..95aa05d4e 100644
--- a/src/dxvk/dxvk_context.cpp
+++ b/src/dxvk/dxvk_context.cpp
@@ -1052,17 +1052,19 @@ namespace dxvk {
   
   
   void DxvkContext::drawIndirectXfb(
-    const DxvkBufferSlice&  counterBuffer,
+          VkDeviceSize      counterOffset,
           uint32_t          counterDivisor,
           uint32_t          counterBias) {
-    if (this->commitGraphicsState<false, false>()) {
-      auto physSlice = counterBuffer.getSliceHandle();
+    if (this->commitGraphicsState<false, true>()) {
+      auto physSlice = m_state.id.cntBuffer.getSliceHandle();
 
       m_cmd->cmdDrawIndirectVertexCount(1, 0,
-        physSlice.handle,
-        physSlice.offset,
-        counterBias,
-        counterDivisor);
+        physSlice.handle, physSlice.offset + counterOffset,
+        counterBias, counterDivisor);
+
+      // The count will generally be written from streamout
+      if (likely(m_state.id.cntBuffer.buffer()->hasGfxStores()))
+        accessDrawCountBuffer(counterOffset);
     }
   }
 
diff --git a/src/dxvk/dxvk_context.h b/src/dxvk/dxvk_context.h
index ace683ebf..a3aba78d2 100644
--- a/src/dxvk/dxvk_context.h
+++ b/src/dxvk/dxvk_context.h
@@ -832,14 +832,14 @@ namespace dxvk {
             uint32_t          stride);
     
     /**
-     * \brief Transform feddback draw call
-
-     * \param [in] counterBuffer Xfb counter buffer
+     * \brief Transform feedback draw call
+     *
+     * \param [in] counterOffset Draw count offset
      * \param [in] counterDivisor Vertex stride
      * \param [in] counterBias Counter bias
      */
     void drawIndirectXfb(
-      const DxvkBufferSlice&  counterBuffer,
+            VkDeviceSize      counterOffset,
             uint32_t          counterDivisor,
             uint32_t          counterBias);