[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

@@ -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());
     });
   }
 

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);
     }
   }
 

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);