From 0b6a5db0491ba10972f46223d4fc8fb5e639d3c1 Mon Sep 17 00:00:00 2001
From: Marko Pintera <mp@rsxengine.com>
Date: Thu, 23 Jul 2020 15:02:26 +0200
Subject: [PATCH] Don't assign MTLTextureUsageRenderTarget to linear textures

---
 MoltenVK/MoltenVK/GPUObjects/MVKImage.h         |  2 +-
 MoltenVK/MoltenVK/GPUObjects/MVKImage.mm        |  2 +-
 MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.h  |  4 +++-
 MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm | 11 +++++++++--
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKImage.h b/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
index 0d453737..c66efc41 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
@@ -312,7 +312,7 @@ public:
      * attempting to copy a depth image with a substituted format to and from a buffer.
      */
     inline bool hasExpectedTexelSize() { return _hasExpectedTexelSize; }
-
+    
 	/** Returns the Metal resource options for this image. */
     MTLStorageMode getMTLStorageMode();
 
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm b/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
index 6efd58fa..07cf1a5f 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
@@ -120,7 +120,7 @@ MTLTextureDescriptor* MVKImagePlane::newMTLTextureDescriptor() {
     mtlTexDesc.mipmapLevelCount = _image->_mipLevels;
     mtlTexDesc.sampleCount = mvkSampleCountFromVkSampleCountFlagBits(_image->_samples);
     mtlTexDesc.arrayLength = _image->_arrayLayers;
-    mtlTexDesc.usageMVK = _image->getPixelFormats()->getMTLTextureUsage(_image->_usage, mtlPixFmt, minUsage);
+    mtlTexDesc.usageMVK = _image->getPixelFormats()->getMTLTextureUsage(_image->_usage, mtlPixFmt, minUsage, _image->_isLinear);
     mtlTexDesc.storageModeMVK = _image->getMTLStorageMode();
     mtlTexDesc.cpuCacheMode = _image->getMTLCPUCacheMode();
 
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.h b/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.h
index cf49d8de..0c1a24c6 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.h
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.h
@@ -281,10 +281,12 @@ public:
 	/**
 	 * Returns the Metal texture usage from the Vulkan image usage and Metal format, ensuring that at least the
 	 * usages in minUsage are included, even if they wouldn't naturally be included based on the other two parameters.
+     *  isLinear further restricts the allowed usage to those that are valid for linear textures.
 	 */
 	MTLTextureUsage getMTLTextureUsage(VkImageUsageFlags vkImageUsageFlags,
 									   MTLPixelFormat mtlFormat,
-									   MTLTextureUsage minUsage = MTLTextureUsageUnknown);
+									   MTLTextureUsage minUsage = MTLTextureUsageUnknown,
+                                       bool isLinear = false);
 
 	/** Enumerates all formats that support the given features, calling a specified function for each one. */
 	void enumerateSupportedFormats(VkFormatProperties properties, bool any, std::function<bool(VkFormat)> func);
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm b/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm
index aaa4147a..be97caf8 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKPixelFormats.mm
@@ -453,7 +453,8 @@ VkImageUsageFlags MVKPixelFormats::getVkImageUsageFlags(MTLTextureUsage mtlUsage
 
 MTLTextureUsage MVKPixelFormats::getMTLTextureUsage(VkImageUsageFlags vkImageUsageFlags,
 													MTLPixelFormat mtlFormat,
-													MTLTextureUsage minUsage) {
+													MTLTextureUsage minUsage,
+                                                    bool isLinear) {
 	bool isDepthFmt = isDepthFormat(mtlFormat);
 	bool isStencilFmt = isStencilFormat(mtlFormat);
 	bool isCombinedDepthStencilFmt = isDepthFmt && isStencilFmt;
@@ -484,7 +485,13 @@ MTLTextureUsage MVKPixelFormats::getMTLTextureUsage(VkImageUsageFlags vkImageUsa
 												VK_IMAGE_USAGE_TRANSFER_DST_BIT)) &&	// Scaling a BLIT may use rendering.
 		mvkIsAnyFlagEnabled(mtlFmtCaps, (kMVKMTLFmtCapsColorAtt | kMVKMTLFmtCapsDSAtt))) {
 
-		mvkEnableFlags(mtlUsage, MTLTextureUsageRenderTarget);
+#if MVK_MACOS
+        if(!isLinear) {
+            mvkEnableFlags(mtlUsage, MTLTextureUsageRenderTarget);
+        }
+#else
+        mvkEnableFlags(mtlUsage, MTLTextureUsageRenderTarget);
+#endif
 	}
 
 	// Create view on, but only on color formats, or combined depth-stencil formats if supported by the GPU...