Merge pull request #2142 from cdavis5e/metal-spis

Add more Metal SPI support

Common/MVKCommonEnvironment.h

@@ -125,6 +125,19 @@ extern "C" {
 									 (__IPHONE_OS_VERSION_MAX_ALLOWED >= 140000))
 #endif
 
+/**
+ * Enable use of private Metal APIs.
+ *
+ * Enabling this build setting during a MoltenVK build will allow MoltenVK to
+ * extend its functionality by using certain private Metal API calls, but it 
+ * will also disqualify the app from being distributed via Apple App Stores.
+ *
+ * Disabled by default.
+ */
+#ifndef MVK_USE_METAL_PRIVATE_API
+#	define MVK_USE_METAL_PRIVATE_API		0
+#endif
+
 /** Directive to identify public symbols. */
 #define MVK_PUBLIC_SYMBOL    __attribute__((visibility("default"))) __attribute__((used))
 

Docs/MoltenVK_Configuration_Parameters.md

@@ -663,3 +663,16 @@ Determines the style used to implement _Vulkan_ semaphore (`VkSemaphore`) functi
 In the special case of `VK_SEMAPHORE_TYPE_TIMELINE` semaphores, **MoltenVK** will always use
 `MTLSharedEvent` if it is available on the platform, regardless of the value of this parameter.
 
+
+---------------------------------------
+#### MVK_CONFIG_USE_METAL_PRIVATE_API
+
+##### Type: Boolean
+##### Default: Value of `MVK_USE_METAL_PRIVATE_API`
+
+If enabled, **MoltenVK** will _use_ private interfaces exposed by _Metal_ to implement _Vulkan_
+features that are difficult to support otherwise.
+
+Unlike `MVK_USE_METAL_PRIVATE_API`, this setting may be overridden at run time.
+
+This option is not available unless MoltenVK were built with `MVK_USE_METAL_PRIVATE_API` set to `1`.

Docs/Whats_New.md

@@ -20,6 +20,10 @@ Released TBD
 
 - Add `MVK_USE_METAL_PRIVATE_API` build setting to allow **MoltenVK** to be built with access to _Metal_ private API calls.
 - Add support for `VkPhysicalDeviceFeatures::wideLines` feature when `MVK_USE_METAL_PRIVATE_API` is enabled in a **MoltenVK** build.
+- Add support for the `VkPhysicalDeviceFeatures::logicOp` feature when `MVK_USE_METAL_PRIVATE_API` is enabled in a **MoltenVK** build.
+- Add support for the `VkPhysicalDeviceFeatures::depthBounds` feature on AMD GPUs when `MVK_USE_METAL_PRIVATE_API` is enabled in a **MoltenVK** build.
+- Add support for the `VkPhysicalDevicePortabilitySubsetFeaturesKHR::samplerMipLodBias` feature when `MVK_USE_METAL_PRIVATE_API` is enabled in a **MoltenVK** build.
+- Add support for Metal native pipeline sample masks when `MVK_USE_METAL_PRIVATE_API` is enabled in a **MoltenVK** build.
 - Fix potential crash when using multi-planar images.
 - Ensure buffers available for buffer addresses in push constants.
 - Support `libMoltenVK.dylib` for _iOS Simulator_ architecture.

MoltenVK/MoltenVK.xcodeproj/project.pbxproj

@@ -140,6 +140,10 @@
 		45557A5321C9EFF3008868BD /* MVKCodec.mm in Sources */ = {isa = PBXBuildFile; fileRef = 45557A4D21C9EFF3008868BD /* MVKCodec.mm */; };
 		45557A5421C9EFF3008868BD /* MVKCodec.h in Headers */ = {isa = PBXBuildFile; fileRef = 45557A5121C9EFF3008868BD /* MVKCodec.h */; };
 		45557A5521C9EFF3008868BD /* MVKCodec.h in Headers */ = {isa = PBXBuildFile; fileRef = 45557A5121C9EFF3008868BD /* MVKCodec.h */; };
+		45E3A40B2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h in Headers */ = {isa = PBXBuildFile; fileRef = 45E3A4062166B922005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h */; };
+		45E3A40C2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h in Headers */ = {isa = PBXBuildFile; fileRef = 45E3A4062166B922005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h */; };
+		45E3A40D2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m in Sources */ = {isa = PBXBuildFile; fileRef = 45E3A40A2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m */; };
+		45E3A40E2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m in Sources */ = {isa = PBXBuildFile; fileRef = 45E3A40A2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m */; };
 		A9096E5E1F81E16300DFBEA6 /* MVKCmdDispatch.mm in Sources */ = {isa = PBXBuildFile; fileRef = A9096E5D1F81E16300DFBEA6 /* MVKCmdDispatch.mm */; };
 		A9096E5F1F81E16300DFBEA6 /* MVKCmdDispatch.mm in Sources */ = {isa = PBXBuildFile; fileRef = A9096E5D1F81E16300DFBEA6 /* MVKCmdDispatch.mm */; };
 		A909F65F213B190700FCD6BE /* MVKExtensions.h in Headers */ = {isa = PBXBuildFile; fileRef = A909F65A213B190600FCD6BE /* MVKExtensions.h */; };
@@ -582,6 +586,8 @@
 		45557A4D21C9EFF3008868BD /* MVKCodec.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = MVKCodec.mm; sourceTree = "<group>"; };
 		45557A5121C9EFF3008868BD /* MVKCodec.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MVKCodec.h; sourceTree = "<group>"; };
 		45557A5721CD83C3008868BD /* MVKDXTnCodec.def */ = {isa = PBXFileReference; explicitFileType = sourcecode.cpp.h; fileEncoding = 4; path = MVKDXTnCodec.def; sourceTree = "<group>"; };
+		45E3A4062166B922005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h"; sourceTree = "<group>"; };
+		45E3A40A2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m"; sourceTree = "<group>"; };
 		A9096E5C1F81E16300DFBEA6 /* MVKCmdDispatch.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MVKCmdDispatch.h; sourceTree = "<group>"; };
 		A9096E5D1F81E16300DFBEA6 /* MVKCmdDispatch.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = MVKCmdDispatch.mm; sourceTree = "<group>"; };
 		A909F65A213B190600FCD6BE /* MVKExtensions.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MVKExtensions.h; sourceTree = "<group>"; };
@@ -904,6 +910,8 @@
 				453638302508A4C6000EFFD3 /* MTLRenderPassStencilAttachmentDescriptor+MoltenVK.m */,
 				A9E53DFE21064F84002781DD /* MTLRenderPipelineDescriptor+MoltenVK.h */,
 				A9E53DFA21064F84002781DD /* MTLRenderPipelineDescriptor+MoltenVK.m */,
+				45E3A4062166B922005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h */,
+				45E3A40A2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m */,
 				A9E53DD32100B197002781DD /* MTLSamplerDescriptor+MoltenVK.h */,
 				A9E53DCD2100B197002781DD /* MTLSamplerDescriptor+MoltenVK.m */,
 				A9E53DD02100B197002781DD /* MTLTextureDescriptor+MoltenVK.h */,
@@ -1086,6 +1094,7 @@
 				A94FB7BC1C7DFB4800632CA3 /* MVKCmdPipeline.h in Headers */,
 				A9F3D9DC24732A4D00745190 /* MVKSmallVectorAllocator.h in Headers */,
 				A9C327562AAFBD390025EE79 /* MVKConfigMembers.def in Headers */,
+				45E3A40B2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h in Headers */,
 				A94FB7F81C7DFB4800632CA3 /* MVKPipeline.h in Headers */,
 				A94FB7F01C7DFB4800632CA3 /* MVKImage.h in Headers */,
 				4553AEFD2251617100E8EBCD /* MVKBlockObserver.h in Headers */,
@@ -1163,6 +1172,7 @@
 				A94FB7C51C7DFB4800632CA3 /* MVKCmdRendering.h in Headers */,
 				A94FB7BD1C7DFB4800632CA3 /* MVKCmdPipeline.h in Headers */,
 				A9F3D9DD24732A4D00745190 /* MVKSmallVectorAllocator.h in Headers */,
+				45E3A40C2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.h in Headers */,
 				A94FB7F91C7DFB4800632CA3 /* MVKPipeline.h in Headers */,
 				A9C327582AAFBD3A0025EE79 /* MVKConfigMembers.def in Headers */,
 				A94FB7F11C7DFB4800632CA3 /* MVKImage.h in Headers */,
@@ -1776,6 +1786,7 @@
 				A9E53DE92100B197002781DD /* CAMetalLayer+MoltenVK.mm in Sources */,
 				A9096E5E1F81E16300DFBEA6 /* MVKCmdDispatch.mm in Sources */,
 				A99C90F0229455B300A061DA /* MVKCmdDebug.mm in Sources */,
+				45E3A40D2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1836,6 +1847,7 @@
 				A9E53DEA2100B197002781DD /* CAMetalLayer+MoltenVK.mm in Sources */,
 				A9096E5F1F81E16300DFBEA6 /* MVKCmdDispatch.mm in Sources */,
 				A99C90F1229455B300A061DA /* MVKCmdDebug.mm in Sources */,
+				45E3A40E2166B923005E3E38 /* MTLRenderPipelineColorAttachmentDescriptor+MoltenVK.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

MoltenVK/MoltenVK/API/mvk_datatypes.h

@@ -342,6 +342,9 @@ MTLBlendOperation mvkMTLBlendOperationFromVkBlendOp(VkBlendOp vkBlendOp);
 /** Returns the Metal MTLBlendFactor corresponding to the specified Vulkan VkBlendFactor. */
 MTLBlendFactor mvkMTLBlendFactorFromVkBlendFactor(VkBlendFactor vkBlendFactor);
 
+/** Returns the Metal MTLLogicOperation corresponding to the specified Vulkan VkLogicOp. */
+NSUInteger mvkMTLLogicOperationFromVkLogicOp(VkLogicOp vkBlendOp);
+
 /**
  * Returns the Metal MTLVertexFormat corresponding to the specified
  * Vulkan VkFormat as used as a vertex attribute format.

MoltenVK/MoltenVK/API/mvk_private_api.h

@@ -240,6 +240,8 @@ typedef struct {
 	MVKConfigCompressionAlgorithm shaderSourceCompressionAlgorithm;            /**< MVK_CONFIG_SHADER_COMPRESSION_ALGORITHM */
 	VkBool32 shouldMaximizeConcurrentCompilation;                              /**< MVK_CONFIG_SHOULD_MAXIMIZE_CONCURRENT_COMPILATION */
 	float timestampPeriodLowPassAlpha;                                         /**< MVK_CONFIG_TIMESTAMP_PERIOD_LOWPASS_ALPHA */
+	VkBool32 useMetalPrivateAPI;                                               /**< MVK_CONFIG_USE_METAL_PRIVATE_API */
+	uint32_t _unused_struct_padding;
 } MVKConfiguration;
 
 // Legacy support for renamed struct elements.

MoltenVK/MoltenVK/Commands/MVKCmdRendering.h

@@ -375,6 +375,41 @@ class MVKCmdSetDepthCompareOp : public MVKSingleValueCommand<VkCompareOp> {
 };
 
 
+#pragma mark -
+#pragma mark MVKCmdSetDepthBounds
+
+/** Vulkan command to set depth bounds. */
+class MVKCmdSetDepthBounds : public MVKCommand {
+
+public:
+    VkResult setContent(MVKCommandBuffer* cmdBuff,
+                        float minDepthBounds,
+                        float maxDepthBounds);
+
+    void encode(MVKCommandEncoder* cmdEncoder) override;
+
+protected:
+    MVKCommandTypePool<MVKCommand>* getTypePool(MVKCommandPool* cmdPool) override;
+
+    float _minDepthBounds;
+    float _maxDepthBounds;
+};
+
+
+#pragma mark -
+#pragma mark MVKCmdSetDepthBoundsTestEnable
+
+/** Vulkan command to enable depth bounds testing. */
+class MVKCmdSetDepthBoundsTestEnable : public MVKSingleValueCommand<VkBool32> {
+
+public:
+    void encode(MVKCommandEncoder* cmdEncoder) override;
+
+protected:
+    MVKCommandTypePool<MVKCommand>* getTypePool(MVKCommandPool* cmdPool) override;
+};
+
+
 #pragma mark -
 #pragma mark MVKCmdSetStencilTestEnable
 

MoltenVK/MoltenVK/Commands/MVKCmdRendering.mm

@@ -327,6 +327,30 @@
 }
 
 
+#pragma mark -
+#pragma mark MVKCmdSetDepthBounds
+
+VkResult MVKCmdSetDepthBounds::setContent(MVKCommandBuffer* cmdBuff,
+										  float minDepthBounds,
+										  float maxDepthBounds) {
+    _minDepthBounds = minDepthBounds;
+    _maxDepthBounds = maxDepthBounds;
+	return VK_SUCCESS;
+}
+
+void MVKCmdSetDepthBounds::encode(MVKCommandEncoder* cmdEncoder) {
+	cmdEncoder->_renderingState.setDepthBounds(_minDepthBounds, _maxDepthBounds, true);
+}
+
+
+#pragma mark -
+#pragma mark MVKCmdSetDepthBoundsTestEnable
+
+void MVKCmdSetDepthBoundsTestEnable::encode(MVKCommandEncoder* cmdEncoder) {
+    cmdEncoder->_renderingState.setDepthBoundsTestEnable(_value, true);
+}
+
+
 #pragma mark -
 #pragma mark MVKCmdSetStencilTestEnable
 

MoltenVK/MoltenVK/Commands/MVKCommandEncoderState.h

@@ -239,6 +239,11 @@ struct MVKDepthBias {
 	float depthBiasClamp;
 };
 
+struct MVKDepthBounds {
+	float minDepthBound;
+	float maxDepthBound;
+};
+
 struct MVKStencilReference {
 	uint32_t frontFaceValue;
 	uint32_t backFaceValue;
@@ -272,6 +277,8 @@ class MVKRenderingCommandEncoderState : public MVKCommandEncoderState {
 	void setDepthBiasEnable(VkBool32 depthBiasEnable);
 	void setDepthClipEnable(bool depthClip, bool isDynamic);
 
+	void setDepthBounds(float minDepthBounds, float maxDepthBounds, bool isDynamic);
+	void setDepthBoundsTestEnable(VkBool32 depthBoundsTestEnable, bool isDynamic);
 	void setStencilReferenceValues(const VkPipelineDepthStencilStateCreateInfo& vkDepthStencilInfo);
 	void setStencilReferenceValues(VkStencilFaceFlags faceMask, uint32_t stencilReference);
 
@@ -318,6 +325,7 @@ class MVKRenderingCommandEncoderState : public MVKCommandEncoderState {
 	MVKMTLScissors _mtlScissors[StateScope::Count] = {};
 	MVKColor32 _mtlBlendConstants[StateScope::Count] = {};
 	MVKDepthBias _mtlDepthBias[StateScope::Count] = {};
+	MVKDepthBounds _mtlDepthBounds[StateScope::Count] = {};
 	MVKStencilReference _mtlStencilReference[StateScope::Count] = {};
 	MTLCullMode _mtlCullMode[StateScope::Count] = { MTLCullModeNone, MTLCullModeNone };
 	MTLWinding _mtlFrontFace[StateScope::Count] = { MTLWindingClockwise, MTLWindingClockwise };
@@ -332,6 +340,7 @@ class MVKRenderingCommandEncoderState : public MVKCommandEncoderState {
 	bool _mtlDepthBiasEnable[StateScope::Count] = {};
 	bool _mtlPrimitiveRestartEnable[StateScope::Count] = {};
 	bool _mtlRasterizerDiscardEnable[StateScope::Count] = {};
+	bool _mtlDepthBoundsTestEnable[StateScope::Count] = {};
 	bool _cullBothFaces[StateScope::Count] = {};
 	bool _isPolygonModePoint[StateScope::Count] = {};
 };

MoltenVK/MoltenVK/Commands/MVKCommandEncoderState.mm

@@ -369,6 +369,16 @@
 	setMTLContent(DepthClipEnable);
 }
 
+void MVKRenderingCommandEncoderState::setDepthBounds(float minDepthBounds, float maxDepthBounds, bool isDynamic) {
+	MVKDepthBounds mtlDepthBounds = { minDepthBounds, maxDepthBounds };
+	setMTLContent(DepthBounds);
+}
+
+void MVKRenderingCommandEncoderState::setDepthBoundsTestEnable(VkBool32 depthBoundsTestEnable, bool isDynamic) {
+	auto mtlDepthBoundsTestEnable = static_cast<bool>(depthBoundsTestEnable);
+	setMTLContent(DepthBoundsTestEnable);
+}
+
 void MVKRenderingCommandEncoderState::setStencilReferenceValues(const VkPipelineDepthStencilStateCreateInfo& vkDepthStencilInfo) {
 	bool isDynamic = false;
 	MVKStencilReference mtlStencilReference = {
@@ -545,6 +555,14 @@
 // An extension of the MTLRenderCommandEncoder protocol to declare the setLineWidth: method.
 @protocol MVKMTLRenderCommandEncoderLineWidth <MTLRenderCommandEncoder>
 -(void) setLineWidth: (float) width;
+@end
+
+// An extension of the MTLRenderCommandEncoder protocol containing a declaration of the
+// -setDepthBoundsTestAMD:minDepth:maxDepth: method.
+@protocol MVKMTLRenderCommandEncoderDepthBoundsAMD <MTLRenderCommandEncoder>
+
+- (void)setDepthBoundsTestAMD:(BOOL)enable minDepth:(float)minDepth maxDepth:(float)maxDepth;
+
 @end
 #endif
 
@@ -584,6 +602,21 @@ -(void) setLineWidth: (float) width;
 		[rendEnc setDepthClipMode: getMTLContent(DepthClipEnable)];
 	}
 
+#if MVK_USE_METAL_PRIVATE_API
+    if (getMVKConfig().useMetalPrivateAPI && (isDirty(DepthBoundsTestEnable) || isDirty(DepthBounds)) &&
+		_cmdEncoder->_pDeviceFeatures->depthBounds) {
+		if (getMTLContent(DepthBoundsTestEnable)) {
+			auto& db = getMTLContent(DepthBounds);
+			[(id<MVKMTLRenderCommandEncoderDepthBoundsAMD>)_cmdEncoder->_mtlRenderEncoder setDepthBoundsTestAMD: YES
+					   minDepth: db.minDepthBound
+					   maxDepth: db.maxDepthBound];
+		} else {
+			[(id<MVKMTLRenderCommandEncoderDepthBoundsAMD>)_cmdEncoder->_mtlRenderEncoder setDepthBoundsTestAMD: NO
+					   minDepth: 0.0f
+					   maxDepth: 1.0f];
+		}
+	}
+#endif
 	if (isDirty(StencilReference)) {
 		auto& sr = getMTLContent(StencilReference);
 		[rendEnc setStencilFrontReferenceValue: sr.frontFaceValue backReferenceValue: sr.backFaceValue];

MoltenVK/MoltenVK/Commands/MVKCommandTypePools.def

@@ -90,6 +90,8 @@ MVK_CMD_TYPE_POOLS_FROM_THRESHOLD(SetScissor, 1)
 MVK_CMD_TYPE_POOL(SetBlendConstants)
 MVK_CMD_TYPE_POOL(SetDepthBias)
 MVK_CMD_TYPE_POOL(SetDepthBiasEnable)
+MVK_CMD_TYPE_POOL(SetDepthBounds)
+MVK_CMD_TYPE_POOL(SetDepthBoundsTestEnable)
 MVK_CMD_TYPE_POOL(SetDepthTestEnable)
 MVK_CMD_TYPE_POOL(SetDepthWriteEnable)
 MVK_CMD_TYPE_POOL(SetDepthClipEnable)

MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm

@@ -366,7 +366,7 @@
 				portabilityFeatures->multisampleArrayImage = _metalFeatures.multisampleArrayTextures;
 				portabilityFeatures->mutableComparisonSamplers = _metalFeatures.depthSampleCompare;
 				portabilityFeatures->pointPolygons = false;
-				portabilityFeatures->samplerMipLodBias = false;
+				portabilityFeatures->samplerMipLodBias = getMVKConfig().useMetalPrivateAPI;
 				portabilityFeatures->separateStencilMaskRef = true;
 				portabilityFeatures->shaderSampleRateInterpolationFunctions = _metalFeatures.pullModelInterpolation;
 				portabilityFeatures->tessellationIsolines = false;
@@ -2338,10 +2338,11 @@
     _features.fullDrawIndexUint32 = true;
     _features.independentBlend = true;
     _features.sampleRateShading = true;
+	_features.logicOp = getMVKConfig().useMetalPrivateAPI;
     _features.depthBiasClamp = true;
     _features.fillModeNonSolid = true;
     _features.largePoints = true;
-	_features.wideLines = static_cast<bool>(MVK_USE_METAL_PRIVATE_API);
+	_features.wideLines = getMVKConfig().useMetalPrivateAPI;
     _features.alphaToOne = true;
     _features.samplerAnisotropy = true;
     _features.shaderImageGatherExtended = true;
@@ -2442,6 +2443,13 @@
 
     _features.shaderStorageImageArrayDynamicIndexing = _metalFeatures.arrayOfTextures;
 
+#if MVK_USE_METAL_PRIVATE_API
+    if (getMVKConfig().useMetalPrivateAPI && _properties.vendorID == kAMDVendorId) {
+        // Only AMD drivers have the method we need for now.
+        _features.depthBounds = true;
+    }
+#endif
+
     if (supportsMTLFeatureSet(macOS_GPUFamily1_v2)) {
         _features.tessellationShader = true;
         _features.dualSrcBlend = true;
@@ -2522,6 +2530,10 @@
 
 	_properties.limits.maxImageDimension3D = _metalFeatures.maxTextureLayers;
 	_properties.limits.maxImageArrayLayers = _metalFeatures.maxTextureLayers;
+	// Max sum of API and shader values. Bias not publicly supported in API, but can be applied in the shader directly.
+	// The lack of API value is covered by VkPhysicalDevicePortabilitySubsetFeaturesKHR::samplerMipLodBias.
+	// Metal does not specify a limit for the shader value, so choose something reasonable.
+	_properties.limits.maxSamplerLodBias = getMVKConfig().useMetalPrivateAPI ? 16 : 4;
 	_properties.limits.maxSamplerAnisotropy = 16;
 
     _properties.limits.maxVertexInputAttributes = 31;
@@ -2798,11 +2810,6 @@
 #endif
 	}
 
-	// Max sum of API and shader values. Bias not supported in API, but can be applied in shader directly.
-	// The lack of API value is covered by VkPhysicalDevicePortabilitySubsetFeaturesKHR::samplerMipLodBias.
-	// Metal does not specify limit for shader value, so choose something reasonable.
-	_properties.limits.maxSamplerLodBias = 4;
-
     _properties.limits.minTexelOffset = -8;
     _properties.limits.maxTexelOffset = 7;
     _properties.limits.minTexelGatherOffset = _properties.limits.minTexelOffset;

MoltenVK/MoltenVK/GPUObjects/MVKImage.mm

@@ -2221,6 +2221,11 @@ static MSLSamplerYCbCrRange getSpvSamplerYcbcrRangeFromVkSamplerYcbcrRange(VkSam
     mtlSampDesc.mipFilter = (pCreateInfo->unnormalizedCoordinates
                              ? MTLSamplerMipFilterNotMipmapped
                              : mvkMTLSamplerMipFilterFromVkSamplerMipmapMode(pCreateInfo->mipmapMode));
+#if MVK_USE_METAL_PRIVATE_API
+	if (getMVKConfig().useMetalPrivateAPI) {
+		mtlSampDesc.lodBiasMVK = pCreateInfo->mipLodBias;
+	}
+#endif
 	mtlSampDesc.lodMinClamp = pCreateInfo->minLod;
 	mtlSampDesc.lodMaxClamp = pCreateInfo->maxLod;
 	mtlSampDesc.maxAnisotropy = (pCreateInfo->anisotropyEnable