Merge pull request #9945 from OatmealDome/intel-broken-discard

DriverDetails: Add broken dual source blending bug to MoltenVK on Intel GPUs

Source/Core/VideoBackends/Vulkan/VKPipeline.cpp

@@ -14,6 +14,8 @@
 #include "VideoBackends/Vulkan/VKVertexFormat.h"
 #include "VideoBackends/Vulkan/VulkanContext.h"
 
+#include "VideoCommon/DriverDetails.h"
+
 namespace Vulkan
 {
 VKPipeline::VKPipeline(VkPipeline pipeline, VkPipelineLayout pipeline_layout,
@@ -137,7 +139,11 @@ static VkPipelineColorBlendAttachmentState GetVulkanAttachmentBlendState(const B
   vk_state.colorBlendOp = state.subtract ? VK_BLEND_OP_REVERSE_SUBTRACT : VK_BLEND_OP_ADD;
   vk_state.alphaBlendOp = state.subtractAlpha ? VK_BLEND_OP_REVERSE_SUBTRACT : VK_BLEND_OP_ADD;
 
-  if (state.usedualsrc && g_ActiveConfig.backend_info.bSupportsDualSourceBlend)
+  bool use_dual_source =
+      state.usedualsrc && g_ActiveConfig.backend_info.bSupportsDualSourceBlend &&
+      (!DriverDetails::HasBug(DriverDetails::BUG_BROKEN_DUAL_SOURCE_BLENDING) || state.dstalpha);
+
+  if (use_dual_source)
   {
     static constexpr std::array<VkBlendFactor, 8> src_factors = {
         {VK_BLEND_FACTOR_ZERO, VK_BLEND_FACTOR_ONE, VK_BLEND_FACTOR_DST_COLOR,

Source/Core/VideoBackends/Vulkan/VulkanContext.cpp

@@ -869,8 +869,8 @@ void VulkanContext::InitDriverDetails()
   {
 // Apart from the driver version, Intel does not appear to provide a way to
 // differentiate between anv and the binary driver (Skylake+). Assume to be
-// using anv if we not running on Windows.
-#ifdef WIN32
+// using anv if we're not running on Windows or macOS.
+#if defined(WIN32) || defined(__APPLE__)
     vendor = DriverDetails::VENDOR_INTEL;
     driver = DriverDetails::DRIVER_INTEL;
 #else

Source/Core/VideoCommon/DriverDetails.cpp

@@ -95,6 +95,8 @@ constexpr BugInfo m_known_bugs[] = {
      BUG_BROKEN_DUAL_SOURCE_BLENDING, -1.0, -1.0, true},
     {API_OPENGL, OS_OSX, VENDOR_INTEL, DRIVER_INTEL, Family::UNKNOWN,
      BUG_BROKEN_DUAL_SOURCE_BLENDING, -1.0, -1.0, true},
+    {API_VULKAN, OS_OSX, VENDOR_INTEL, DRIVER_PORTABILITY, Family::UNKNOWN,
+     BUG_BROKEN_DUAL_SOURCE_BLENDING, -1.0, -1.0, true},
     {API_OPENGL, OS_ALL, VENDOR_IMGTEC, DRIVER_IMGTEC, Family::UNKNOWN,
      BUG_BROKEN_BITWISE_OP_NEGATION, -1.0, 108.4693462, true},
     {API_VULKAN, OS_WINDOWS, VENDOR_ATI, DRIVER_ATI, Family::UNKNOWN, BUG_PRIMITIVE_RESTART, -1.0,

Source/Core/VideoCommon/DriverDetails.h

@@ -229,13 +229,16 @@ enum Bug
   // index as a MRT location instead, or omit the binding completely.
   BUG_BROKEN_FRAGMENT_SHADER_INDEX_DECORATION,
 
-  // Bug: Dual-source outputs from fragment shaders are broken on AMD OpenGL drivers
+  // Bug: Dual-source outputs from fragment shaders are broken on some drivers.
   // Started Version: -1
   // Ended Version: -1
-  // Fragment shaders that specify dual-source outputs, cause the driver to crash
-  // sometimes this happens in the kernel mode part of the driver resulting in a BSOD.
-  // Disable dual-source blending support for now.
+  // On some AMD drivers, fragment shaders that specify dual-source outputs can cause the driver to
+  // crash. Sometimes this happens in the kernel mode part of the driver, resulting in a BSOD.
+  // These shaders are also particularly problematic on macOS's Intel drivers. On OpenGL, they can
+  // cause depth issues. On Metal, they can cause the driver to not write a primitive to the depth
+  // buffer whenever a fragment is discarded. Disable dual-source blending support on these drivers.
   BUG_BROKEN_DUAL_SOURCE_BLENDING,
+
   // BUG: ImgTec GLSL shader compiler fails when negating the input to a bitwise operation
   // Started version: 1.5
   // Ended version: 1.8@4693462