Using a generated .r file

[ryandesign]

In my app I want to generate some .r file foo.r at build time. I've done that, but I've been unable to get add_application to accept it because it seems to be hardcoded to expect the .r file to be specified by name only and that it will be in the source directory:

        if(${f} MATCHES "\\.r$")
            add_custom_command(
                OUTPUT ${f}.rsrc.bin
                COMMAND ${REZ} ${REZ_FLAGS} ${CMAKE_CURRENT_SOURCE_DIR}/${f} ${rez_include_options} -o ${f}.rsrc.bin
                DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${f})
            list(APPEND rsrc_files "${CMAKE_CURRENT_BINARY_DIR}/${f}.rsrc.bin")
            list(APPEND rez_files "${f}")

Specifically, this code prepends ${CMAKE_CURRENT_SOURCE_DIR}/ to ${f} to compute the input path and prepends ${CMAKE_CURRENT_BINARY_DIR}/ to ${f} to compute the output path. It doesn't account for ${f} possibly being an absolute path.

I tried giving add_application the foo.r filename only, which didn't work because the file isn't in the source directory, and I tried giving it ${CMAKE_CURRENT_BINARY_DIR}/foo.r which didn't work because ${CMAKE_CURRENT_BINARY_DIR} is an absolute path and the output filename referred to a nonsensical nonexistent path.

Can I accomplish what I want?