Don't enable PixelFormatView just in case we need it to copy

Not worth the performance hit to everything else

MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm

@@ -133,12 +133,17 @@ static inline MTLSize mvkClampMTLSize(MTLSize size, MTLOrigin origin, MTLSize ma
 
         MTLPixelFormat srcMTLPixFmt = _srcImage->getMTLPixelFormat(srcPlaneIndex);
         bool isSrcCompressed = _srcImage->getIsCompressed();
+        bool canReinterpretSrc = _srcImage->hasPixelFormatView();
 
         MTLPixelFormat dstMTLPixFmt = _dstImage->getMTLPixelFormat(dstPlaneIndex);
         bool isDstCompressed = _dstImage->getIsCompressed();
+        bool canReinterpretDst = _dstImage->hasPixelFormatView();
+
+        bool isEitherCompressed = isSrcCompressed || isDstCompressed;
+        bool canReinterpret = canReinterpretSrc || canReinterpretDst;
 
         // If source and destination have different formats and at least one is compressed, use a temporary intermediary buffer
-        bool useTempBuffer = (srcMTLPixFmt != dstMTLPixFmt) && (isSrcCompressed || isDstCompressed);
+        bool useTempBuffer = (srcMTLPixFmt != dstMTLPixFmt) && (isEitherCompressed || !canReinterpret);
 
         if (useTempBuffer) {
             // Add copy from source image to temp buffer.
@@ -177,12 +182,13 @@ static inline MTLSize mvkClampMTLSize(MTLSize size, MTLOrigin origin, MTLSize ma
 
             size_t bytesPerRow = pixFmts->getBytesPerRow(srcMTLPixFmt, vkIC.extent.width);
             size_t bytesPerRegion = pixFmts->getBytesPerLayer(srcMTLPixFmt, bytesPerRow, vkIC.extent.height);
-            tmpBuffSize += bytesPerRegion;
+            tmpBuffSize += bytesPerRegion * vkIC.extent.depth;
         } else {
-            // Map the source pixel format to the dest pixel format through a texture view on the source texture.
-            // If the source and dest pixel formats are the same, this will simply degenerate to the source texture itself.
-            id<MTLTexture> srcMTLTex = _srcImage->getMTLTexture(srcPlaneIndex, _dstImage->getMTLPixelFormat(dstPlaneIndex));
-            id<MTLTexture> dstMTLTex = _dstImage->getMTLTexture(dstPlaneIndex);
+            // Map the source pixel format to the dest pixel format through a texture view on the reinterpretable texture.
+            // If the source and dest pixel formats are the same, this will simply degenerate to the texture itself.
+            MTLPixelFormat fmt = (canReinterpretSrc ? _dstImage : _srcImage)->getMTLPixelFormat(canReinterpretSrc ? dstPlaneIndex : srcPlaneIndex);
+            id<MTLTexture> srcMTLTex = _srcImage->getMTLTexture(srcPlaneIndex, fmt);
+            id<MTLTexture> dstMTLTex = _dstImage->getMTLTexture(dstPlaneIndex, fmt);
             if ( !srcMTLTex || !dstMTLTex ) { return; }
 
             id<MTLBlitCommandEncoder> mtlBlitEnc = cmdEncoder->getMTLBlitEncoder(commandUse);

MoltenVK/MoltenVK/GPUObjects/MVKImage.h

@@ -310,7 +310,10 @@ class MVKImage : public MVKVulkanAPIDeviceObject {
      * attempting to copy a depth image with a substituted format to and from a buffer.
      */
     inline bool hasExpectedTexelSize() { return _hasExpectedTexelSize; }
-
+
+	/** Returns whether the texture has the PixelFormatView usage flag, allowing it to be reinterpreted */
+	inline bool hasPixelFormatView() const { return mvkIsAnyFlagEnabled(_mtlUsage, MTLTextureUsagePixelFormatView); }
+
 	/** Returns the Metal resource options for this image. */
     MTLStorageMode getMTLStorageMode();
 
@@ -354,6 +357,7 @@ class MVKImage : public MVKVulkanAPIDeviceObject {
 	VkImageUsageFlags _stencilUsage;
     VkFormat _vkFormat;
 	MTLTextureType _mtlTextureType;
+	MTLTextureUsage _mtlUsage;
     std::mutex _lock;
     IOSurfaceRef _ioSurface;
 	VkDeviceSize _rowByteAlignment;

MoltenVK/MoltenVK/GPUObjects/MVKImage.mm

@@ -127,7 +127,7 @@
     mtlTexDesc.mipmapLevelCount = _image->_mipLevels;
     mtlTexDesc.sampleCount = mvkSampleCountFromVkSampleCountFlagBits(_image->_samples);
     mtlTexDesc.arrayLength = _image->_arrayLayers;
-	mtlTexDesc.usageMVK = _image->getMTLTextureUsage(mtlPixFmt);
+	mtlTexDesc.usageMVK = _image->_mtlUsage;
     mtlTexDesc.storageModeMVK = _image->getMTLStorageMode();
     mtlTexDesc.cpuCacheMode = _image->getMTLCPUCacheMode();
 
@@ -982,6 +982,8 @@
         }
     }
     _hasExpectedTexelSize = _hasChromaSubsampling || (pixFmts->getBytesPerBlock(_planes[0]->_mtlPixFmt) == pixFmts->getBytesPerBlock(_vkFormat));
+	MTLPixelFormat actualFmt = MVK_MACOS && _is3DCompressed ? MTLPixelFormatBGRA8Unorm : pixFmts->getMTLPixelFormat(pCreateInfo->format);
+	_mtlUsage = getMTLTextureUsage(actualFmt);
 
 	if (pExtMemInfo) { initExternalMemory(pExtMemInfo->handleTypes); }
 
@@ -1763,6 +1765,13 @@ static void signalAndUnmarkAsTracked(const MVKSwapchainSignaler& signaler) {
 		}
 	}
 
+	if (!_imageView->_image->hasPixelFormatView()) {
+		if (!enableSwizzling()) {
+			MVKAssert(0, "Image without PixelFormatView usage couldn't enable swizzling!");
+		}
+		return VK_SUCCESS;
+	}
+
 	switch (_mtlPixFmt) {
 		case MTLPixelFormatR8Unorm:
 			if (SWIZZLE_MATCHES(ZERO, ANY, ANY, R)) {

MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm

@@ -737,23 +737,23 @@
 		mvkEnableFlags(mtlUsage, samples == VK_SAMPLE_COUNT_1_BIT ? MTLTextureUsageShaderWrite : MTLTextureUsageShaderRead);
 	}
 
-	// Create view on, but only on color formats, or combined depth-stencil formats if supported by the GPU...
-	if ((mvkIsAnyFlagEnabled(vkImageUsageFlags, (VK_IMAGE_USAGE_TRANSFER_SRC_BIT)) || 		// May use temp view if transfer involves format change
-		 (needsReinterpretation &&
-		  mvkIsAnyFlagEnabled(vkImageUsageFlags, (VK_IMAGE_USAGE_SAMPLED_BIT |
-												  VK_IMAGE_USAGE_STORAGE_BIT |
-												  VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT |
-												  VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT)))) &&
-		isColorFormat) {
-
-		mvkEnableFlags(mtlUsage, MTLTextureUsagePixelFormatView);
-	}
-	if (mvkIsAnyFlagEnabled(vkImageUsageFlags, (VK_IMAGE_USAGE_TRANSFER_SRC_BIT | 		// May use temp view if transfer involves format change
-		 										VK_IMAGE_USAGE_SAMPLED_BIT |
-												VK_IMAGE_USAGE_STORAGE_BIT |
-												VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT)) &&
-		isCombinedDepthStencilFmt && supportsStencilViews) {
-
+	bool pfv = false;
+
+	// Swizzle emulation may need to reinterpret
+	needsReinterpretation |= !_physicalDevice->getMetalFeatures()->nativeTextureSwizzle;
+
+	pfv |= isColorFormat && needsReinterpretation &&
+	       mvkIsAnyFlagEnabled(vkImageUsageFlags, (VK_IMAGE_USAGE_SAMPLED_BIT |
+	                                               VK_IMAGE_USAGE_STORAGE_BIT |
+	                                               VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT |
+	                                               VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT));
+	pfv |= isCombinedDepthStencilFmt && supportsStencilViews &&
+	       mvkIsAnyFlagEnabled(vkImageUsageFlags, (VK_IMAGE_USAGE_TRANSFER_SRC_BIT | // May use temp view if transfer involves format change
+	                                               VK_IMAGE_USAGE_SAMPLED_BIT |
+	                                               VK_IMAGE_USAGE_STORAGE_BIT |
+	                                               VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT));
+
+	if (pfv) {
 		mvkEnableFlags(mtlUsage, MTLTextureUsagePixelFormatView);
 	}