From 6f87ccdafc8ef72ba0e6d312190363d682a13060 Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Thu, 15 Jun 2023 19:02:26 +0100
Subject: [PATCH] [d3d11] Use FORCE_UNORM depth bias representation for UNORM
 formats

---
 src/d3d11/d3d11_context.cpp | 23 ++++++++++++++++++++++-
 src/d3d11/d3d11_device.cpp  |  5 +++++
 src/d3d11/d3d11_view_dsv.h  |  4 ++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/d3d11/d3d11_context.cpp b/src/d3d11/d3d11_context.cpp
index d2440135..822c0d5f 100644
--- a/src/d3d11/d3d11_context.cpp
+++ b/src/d3d11/d3d11_context.cpp
@@ -3389,8 +3389,24 @@ namespace dxvk {
   }
 
 
+  static VkDepthBiasRepresentationEXT FormatToDepthBiasRepresentation(DXGI_FORMAT format) {
+    switch (format) {
+      default:
+      case DXGI_FORMAT_D32_FLOAT_S8X24_UINT:
+      case DXGI_FORMAT_D32_FLOAT:
+        return VK_DEPTH_BIAS_REPRESENTATION_LEAST_REPRESENTABLE_VALUE_FORMAT_EXT;
+
+      case DXGI_FORMAT_D24_UNORM_S8_UINT:
+      case DXGI_FORMAT_D16_UNORM:
+        return VK_DEPTH_BIAS_REPRESENTATION_LEAST_REPRESENTABLE_VALUE_FORCE_UNORM_EXT;
+    }
+  }
+
   template<typename ContextType>
   void D3D11CommonContext<ContextType>::BindFramebuffer() {
+    DxvkDepthBiasRepresentation depthBiasRepresentation =
+      { VK_DEPTH_BIAS_REPRESENTATION_LEAST_REPRESENTABLE_VALUE_FORMAT_EXT,
+        m_device->features().extDepthBiasControl.depthBiasExact };
     DxvkRenderTargets attachments;
     uint32_t sampleCount = 0;
 
@@ -3411,12 +3427,17 @@ namespace dxvk {
         m_state.om.dsv->GetImageView(),
         m_state.om.dsv->GetRenderLayout() };
       sampleCount = m_state.om.dsv->GetSampleCount();
+
+      if (m_device->features().extDepthBiasControl.leastRepresentableValueForceUnormRepresentation)
+        depthBiasRepresentation.depthBiasRepresentation = FormatToDepthBiasRepresentation(m_state.om.dsv->GetViewFormat());
     }
 
     // Create and bind the framebuffer object to the context
     EmitCs([
-      cAttachments = std::move(attachments)
+      cAttachments    = std::move(attachments),
+      cRepresentation = depthBiasRepresentation
     ] (DxvkContext* ctx) mutable {
+      ctx->setDepthBiasRepresentation(cRepresentation);
       ctx->bindRenderTargets(Forwarder::move(cAttachments), 0u);
     });
 
diff --git a/src/d3d11/d3d11_device.cpp b/src/d3d11/d3d11_device.cpp
index 2db6f9e4..bc107eff 100644
--- a/src/d3d11/d3d11_device.cpp
+++ b/src/d3d11/d3d11_device.cpp
@@ -1953,6 +1953,11 @@ namespace dxvk {
     enabled.core.features.shaderFloat64                           = supported.core.features.shaderFloat64;
     enabled.core.features.shaderInt64                             = supported.core.features.shaderInt64;
 
+    // Depth bias control
+    enabled.extDepthBiasControl.depthBiasControl                                = supported.extDepthBiasControl.depthBiasControl;
+    enabled.extDepthBiasControl.depthBiasExact                                  = supported.extDepthBiasControl.depthBiasExact;
+    enabled.extDepthBiasControl.leastRepresentableValueForceUnormRepresentation = supported.extDepthBiasControl.leastRepresentableValueForceUnormRepresentation;
+
     return enabled;
   }
   
diff --git a/src/d3d11/d3d11_view_dsv.h b/src/d3d11/d3d11_view_dsv.h
index a07d29b2..de1958fc 100644
--- a/src/d3d11/d3d11_view_dsv.h
+++ b/src/d3d11/d3d11_view_dsv.h
@@ -77,6 +77,10 @@ namespace dxvk {
       return mask;
     }
 
+    DXGI_FORMAT GetViewFormat() const {
+      return m_desc.Format;
+    }
+
     D3D10DepthStencilView* GetD3D10Iface() {
       return &m_d3d10;
     }