Cannot find fd_forward.c document

Using Arduino Programming Questions
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Hey~everybody，
Today I try to learn about face detection function.But I cannot find (fd_forward.c) and other .c document.I wonder how can the sample Compile successfully without (fd_forward.c) through arduino IDE?

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Duplicate topics merged

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I don't know? Wherever you got all you other source code perhaps? Although you neglected to tell us where...
Here maybe?