Metal: Fixed msaa capture

src/renderer_mtl.mm

@@ -540,6 +540,12 @@ namespace bgfx { namespace mtl
 				||  BX_ENABLED(BX_PLATFORM_OSX)
 				|| (BX_ENABLED(BX_PLATFORM_IOS) && iOSVersionEqualOrGreater("9.0.0") )
 				;
+			
+			m_hasStoreActionStoreAndMultisampleResolve = false
+			|| (BX_ENABLED(BX_PLATFORM_OSX) && macOSVersionEqualOrGreater(10,12,0))
+			|| (BX_ENABLED(BX_PLATFORM_IOS) && iOSVersionEqualOrGreater("10.0.0") )
+			;
+			
 			m_macOS11Runtime = true
 				&& BX_ENABLED(BX_PLATFORM_OSX)
 				&& macOSVersionEqualOrGreater(10,11,0)
@@ -1333,6 +1339,9 @@ namespace bgfx { namespace mtl
 					if (NULL != desc.texture)
 					{
 						desc.loadAction = MTLLoadActionLoad;
+						desc.storeAction = desc.resolveTexture == nil ?
+											MTLStoreActionStore :
+											MTLStoreActionMultisampleResolve;
 					}
 				}
 
@@ -1340,14 +1349,18 @@ namespace bgfx { namespace mtl
 				if (NULL != depthAttachment.texture)
 				{
 					depthAttachment.loadAction = MTLLoadActionLoad;
-					depthAttachment.storeAction = MTLStoreActionStore;
+					depthAttachment.storeAction = depthAttachment.resolveTexture == nil ?
+													MTLStoreActionStore :
+													MTLStoreActionMultisampleResolve;
 				}
 
 				RenderPassStencilAttachmentDescriptor stencilAttachment = renderPassDescriptor.stencilAttachment;
 				if (NULL != stencilAttachment.texture)
 				{
 					stencilAttachment.loadAction   = MTLLoadActionLoad;
-					stencilAttachment.storeAction  = MTLStoreActionStore;
+					stencilAttachment.storeAction = stencilAttachment.resolveTexture == nil ?
+													MTLStoreActionStore :
+													MTLStoreActionMultisampleResolve;
 				}
 
 				m_renderCommandEncoder = m_commandBuffer.renderCommandEncoderWithDescriptor(renderPassDescriptor);
@@ -2292,6 +2305,7 @@ namespace bgfx { namespace mtl
 		bool m_iOS9Runtime;
 		bool m_macOS11Runtime;
 		bool m_hasPixelFormatDepth32Float_Stencil8;
+		bool m_hasStoreActionStoreAndMultisampleResolve;
 
 		Buffer   m_uniformBuffer;
 		Buffer   m_uniformBuffers[MTL_MAX_FRAMES_IN_FLIGHT];
@@ -3891,7 +3905,17 @@ namespace bgfx { namespace mtl
 											desc.loadAction = MTLLoadActionLoad;
 										}
 
-										desc.storeAction = desc.texture.sampleCount > 1 ? MTLStoreActionMultisampleResolve : MTLStoreActionStore;
+										if ( NULL != m_capture &&
+											!isValid(fbh) &&
+											m_hasStoreActionStoreAndMultisampleResolve)
+										{
+											desc.storeAction = desc.texture.sampleCount > 1 ? MTLStoreActionStoreAndMultisampleResolve : MTLStoreActionStore;
+
+										}
+										else
+										{
+											desc.storeAction = desc.texture.sampleCount > 1 ? MTLStoreActionMultisampleResolve : MTLStoreActionStore;
+										}
 									}
 								}