handle image manipulation

Author: tad1

include/nbl/asset/filters/CFlattenRegionsImageFilter.h

@@ -165,6 +165,9 @@ class CFlattenRegionsImageFilter : public CImageFilter<CFlattenRegionsImageFilte
 				if (!CCopyImageFilter::execute(policy,&copy))
 					return false;
 			}
+
+			outImg->getBuffer()->setContentHash({});
+			outImg->setContentHash(inImg->getContentHash());
 			return true;
 		}
 		static inline bool execute(state_type* state)

include/nbl/asset/interchange/IImageAssetHandlerBase.h

@@ -193,6 +193,8 @@ class IImageAssetHandlerBase : public virtual core::IReferenceCounted
 			auto stride = trueExtent.X * getTexelOrBlockBytesize(format);
 
 			performImageFlip(entry, end, trueExtent.Y, stride);
+			image->setContentHash({}); //invalidate content hash
+			image->getBuffer()->setContentHash({});
 		}
 
 		static inline void performImageFlip(uint8_t* entry, uint8_t* end, uint32_t height, uint32_t rowPitch)