Enable sampler lod bias for Xcode 26.

Author: squidbus

MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm

@@ -614,7 +614,11 @@
 				portabilityFeatures->multisampleArrayImage = _metalFeatures.multisampleArrayTextures;
 				portabilityFeatures->mutableComparisonSamplers = _metalFeatures.depthSampleCompare;
 				portabilityFeatures->pointPolygons = false;
+#if MVK_XCODE_26
+				portabilityFeatures->samplerMipLodBias = true;
+#else
 				portabilityFeatures->samplerMipLodBias = getMVKConfig().useMetalPrivateAPI;
+#endif
 				portabilityFeatures->separateStencilMaskRef = true;
 				portabilityFeatures->shaderSampleRateInterpolationFunctions = _metalFeatures.pullModelInterpolation;
 				portabilityFeatures->tessellationIsolines = false;
@@ -3185,10 +3189,7 @@
 
 	_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 = 16;
+	_properties.limits.maxSamplerLodBias = 15.999;
 	_properties.limits.maxSamplerAnisotropy = 16;
 
     _properties.limits.maxVertexInputAttributes = 31;

MoltenVK/MoltenVK/GPUObjects/MVKImage.mm

@@ -2535,7 +2535,9 @@ static MSLSamplerYCbCrRange getSpvSamplerYcbcrRangeFromVkSamplerYcbcrRange(VkSam
     mtlSampDesc.mipFilter = (pCreateInfo->unnormalizedCoordinates
                              ? MTLSamplerMipFilterNotMipmapped
                              : mvkMTLSamplerMipFilterFromVkSamplerMipmapMode(pCreateInfo->mipmapMode));
-#if MVK_USE_METAL_PRIVATE_API
+#if MVK_XCODE_26
+	mtlSampDesc.lodBiasMVK = pCreateInfo->mipLodBias;
+#elif MVK_USE_METAL_PRIVATE_API
 	if (getMVKConfig().useMetalPrivateAPI) {
 		mtlSampDesc.lodBiasMVK = pCreateInfo->mipLodBias;
 	}

MoltenVK/MoltenVK/OS/MTLSamplerDescriptor+MoltenVK.m

@@ -21,7 +21,7 @@
 #include "MVKCommonEnvironment.h"
 
 
-#if MVK_USE_METAL_PRIVATE_API
+#if MVK_USE_METAL_PRIVATE_API && !MVK_XCODE_26
 /** Additional methods not necessarily declared in <Metal/MTLSampler.h>. */
 @interface MTLSamplerDescriptor ()
 
@@ -55,14 +55,14 @@ -(void) setBorderColorMVK: (NSUInteger) color {
 }
 
 -(float) lodBiasMVK {
-#if MVK_USE_METAL_PRIVATE_API
+#if MVK_USE_METAL_PRIVATE_API || MVK_XCODE_26
 	if ( [self respondsToSelector: @selector(lodBias)] ) { return self.lodBias; }
 #endif
 	return 0.0f;
 }
 
 -(void) setLodBiasMVK: (float) bias {
-#if MVK_USE_METAL_PRIVATE_API
+#if MVK_USE_METAL_PRIVATE_API || MVK_XCODE_26
 	if ( [self respondsToSelector: @selector(setLodBias:)] ) { self.lodBias = bias; }
 #endif
 }