vkCmdCopyBufferToImage() & vkCmdCopyImageToBuffer() support a VkBuffer
that is bound to an offseted position in a VkDeviceMemory.

MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm

diff --git a/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm b/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
index 4b1b6dd..e64b752 100644
--- a/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
+++ b/MoltenVK/MoltenVK/Commands/MVKCmdTransfer.mm
@@ -630,6 +630,7 @@
     id<MTLTexture> mtlTexture = _image->getMTLTexture();
     if ( !mtlBuffer || !mtlTexture ) { return; }
 
+	NSUInteger mtlBuffOffset = _buffer->getMTLBufferOffset();
     MTLPixelFormat mtlPixFmt = mtlTexture.pixelFormat;
     MVKCommandUse cmdUse = _toImage ? kMVKCommandUseCopyBufferToImage : kMVKCommandUseCopyImageToBuffer;
     id<MTLBlitCommandEncoder> mtlBlitEnc = cmdEncoder->getMTLBlitEncoder(cmdUse);
@@ -671,7 +672,7 @@
         for (uint32_t lyrIdx = 0; lyrIdx < cpyRgn.imageSubresource.layerCount; lyrIdx++) {
             if (_toImage) {
                 [mtlBlitEnc copyFromBuffer: mtlBuffer
-                              sourceOffset: (cpyRgn.bufferOffset + (bytesPerImg * lyrIdx))
+                              sourceOffset: (mtlBuffOffset + cpyRgn.bufferOffset + (bytesPerImg * lyrIdx))
                          sourceBytesPerRow: bytesPerRow
                        sourceBytesPerImage: bytesPerImg
                                 sourceSize: mtlTxtSize
@@ -687,7 +688,7 @@
                                sourceOrigin: mtlTxtOrigin
                                  sourceSize: mtlTxtSize
                                    toBuffer: mtlBuffer
-                          destinationOffset: (cpyRgn.bufferOffset + (bytesPerImg * lyrIdx))
+                          destinationOffset: (mtlBuffOffset + cpyRgn.bufferOffset + (bytesPerImg * lyrIdx))
                      destinationBytesPerRow: bytesPerRow
                    destinationBytesPerImage: bytesPerImg
                                     options: blitOptions];

README.md

diff --git a/README.md b/README.md
index c7cb8e6..6edbd61 100644
--- a/README.md
+++ b/README.md
@@ -75,7 +75,7 @@
 		brew install cmake
 		brew install python3
 
-   For faster dependencies build, you can also install Ninja:
+   For faster dependency builds, you can also optionally install `ninja`:
 
 		brew install ninja