From b738c4220b7f2ea71cf2f1f61521a08606ee7022 Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Tue, 7 Jan 2020 23:34:35 +0000
Subject: [PATCH] [d3d9] Scale depth bias value based on current format's `r`
 value

---
 src/d3d9/d3d9_device.cpp | 13 +++++++++----
 src/d3d9/d3d9_device.h   |  2 ++
 src/d3d9/d3d9_util.h     | 16 ++++++++++++++++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/d3d9/d3d9_device.cpp b/src/d3d9/d3d9_device.cpp
index 0f0cafbb9..bf6dfab28 100644
--- a/src/d3d9/d3d9_device.cpp
+++ b/src/d3d9/d3d9_device.cpp
@@ -1231,6 +1231,14 @@ namespace dxvk {
     FlushImplicit(FALSE);
     m_flags.set(D3D9DeviceFlag::DirtyFramebuffer);
 
+    if (ds != nullptr) {
+      float rValue = GetDepthBufferRValue(ds->GetCommonTexture()->GetFormatMapping().FormatColor);
+      if (m_depthBiasScale != rValue) {
+        m_depthBiasScale = rValue;
+        m_flags.set(D3D9DeviceFlag::DirtyDepthBias);
+      }
+    }
+
     m_state.depthStencil = ds;
 
     return D3D_OK;
@@ -5096,12 +5104,9 @@ namespace dxvk {
   void D3D9DeviceEx::BindDepthBias() {
     m_flags.clr(D3D9DeviceFlag::DirtyDepthBias);
 
-    // TODO: Can we get a specific non-magic number in Vulkan for this based on device/adapter?
-    constexpr float DepthBiasFactor = float(1 << 23);
-
     auto& rs = m_state.renderStates;
 
-    float depthBias            = bit::cast<float>(rs[D3DRS_DEPTHBIAS]) * DepthBiasFactor;
+    float depthBias            = bit::cast<float>(rs[D3DRS_DEPTHBIAS]) * m_depthBiasScale;
     float slopeScaledDepthBias = bit::cast<float>(rs[D3DRS_SLOPESCALEDEPTHBIAS]);
 
     DxvkDepthBias biases;
diff --git a/src/d3d9/d3d9_device.h b/src/d3d9/d3d9_device.h
index bf287cc4a..7fffa50b9 100644
--- a/src/d3d9/d3d9_device.h
+++ b/src/d3d9/d3d9_device.h
@@ -1025,6 +1025,8 @@ namespace dxvk {
     bool                            m_nvATOC          = false;
     bool                            m_ffZTest         = false;
 
+    float                           m_depthBiasScale  = 0.0f;
+
     D3D9ConstantLayout              m_vsLayout;
     D3D9ConstantLayout              m_psLayout;
 
diff --git a/src/d3d9/d3d9_util.h b/src/d3d9/d3d9_util.h
index 86585647e..50be2daf0 100644
--- a/src/d3d9/d3d9_util.h
+++ b/src/d3d9/d3d9_util.h
@@ -176,6 +176,22 @@ namespace dxvk {
 
   void ConvertRect(RECT rect, VkOffset2D& offset, VkExtent2D& extent);
 
+  inline float GetDepthBufferRValue(VkFormat Format) {
+    switch (Format) {
+      case VK_FORMAT_D16_UNORM_S8_UINT:
+      case VK_FORMAT_D16_UNORM:
+        return float(1 << 16);
+
+      case VK_FORMAT_D24_UNORM_S8_UINT:
+        return float(1 << 24);
+
+      default:
+      case VK_FORMAT_D32_SFLOAT_S8_UINT:
+      case VK_FORMAT_D32_SFLOAT:
+        return float(1 << 23);
+    }
+  }
+
   template<typename T>
   UINT CompactSparseList(T* pData, UINT Mask) {
     uint32_t count = 0;