message: Fix shader compilation on Windows
diff: @@ -55,12 +55,14 @@ set(CAT_COMMAND cat)
  set(DOUBLEQUOTE "\\\"")
  set(OPENP "\\(")
  set(CLOSEP "\\)")
  +set(SEMICOLON "\;")
  if (WIN32)
  set(CAT_COMMAND type)
  set(DOUBLEQUOTE "^\"")
  set(OPENP "(")
  set(CLOSEP ")")
  + set(SEMICOLON ";")
  endif()
  foreach (shader_file ${SHADERS})
  @@ -78,13 +80,15 @@ foreach (shader_file ${SHADERS})
  set(output_path "${GENERATION_ROOT}/generated/shaders/${localname}.cpp")
  add_custom_command(
  OUTPUT ${output_path}
  - COMMAND echo "namespace filament {" > ${output_path}
  - COMMAND echo "namespace shaders {" >> ${output_path}
  - COMMAND echo "extern const char ${filename}_${extension}[] = R${DOUBLEQUOTE}FILAMENT__${OPENP}" >> ${output_path}
  + # For cross-platform compatibility, each string passed to echo must be enclosed in
  + # double quotes and contain no spaces
  + COMMAND echo "namespace" "filament" "{" > ${output_path}
  + COMMAND echo "namespace" "shaders" "{" >> ${output_path}
  + COMMAND echo "extern" "const" "char" "${filename}_${extension}[]" "=" "R${DOUBLEQUOTE}FILAMENT__${OPENP}" >> ${output_path}
  COMMAND ${CAT_COMMAND} \"${fullname}\" >> \"${output_path}\"
  - COMMAND echo "${CLOSEP}FILAMENT__${DOUBLEQUOTE}\;" >> ${output_path}
  - COMMAND echo "} // namespace shaders" >> ${output_path}
  - COMMAND echo "} // namespace filament" >> ${output_path}
  + COMMAND echo "${CLOSEP}FILAMENT__${DOUBLEQUOTE}${SEMICOLON}" >> ${output_path}
  + COMMAND echo "}" "//" "namespace" "shaders" >> ${output_path}
  + COMMAND echo "}" "//" "namespace" "filament" >> ${output_path}
  DEPENDS ${shader_file}
  COMMENT "Processing shader ${shader_file}"
  )
  