doc/Makefile: refactoring

The initial sketch did work but was somewhat redundant
while lacking the knob conveniently change output directory
as well as means to get it cleaned up.

doc/Makefile

@@ -1,31 +1,50 @@
+# build asciidoc books
+
+ifdef BUILDDIR
+DEST = -D "$(BUILDDIR)"
+endif
+
+ifdef DEBUG
+VERBOSE = --verbose
+endif
+
 PROJECT = mkimage-profiles
-TOPLEVEL_DOC = mkimage-profiles.asciidoc
-HTMLPAGE = $(TOPLEVEL_DOC:.asciidoc=.html)
+TOPLEVEL_DOC = $(PROJECT).asciidoc
 RESOURCE_FILES = /etc/asciidoc
 
 A2X = a2x
+FXC = .fop.xconf
 
-.PHONY: all clean
+L = ru
+DEPTH = 3
 
-all: $(HTMLPAGE)
+# common args (and the source file to process) come last
+XSLT_ARGS = --stringparam toc.max.depth $(DEPTH)
+COMMON_ARGS = -d book -a lang="$L" $(DEST) $(VERBOSE) $(TOPLEVEL_DOC)
+HTML_ARGS = -a data-uri --icons -r $(RESOURCE_FILES) -r . \
+	    --xsltproc-opts='$(XSLT_ARGS)' $(COMMON_ARGS)
 
-%.html: %.asciidoc
-	$(A2X) -d book -f xhtml -a lang=ru \
-	  --icons -r $(RESOURCE_FILES) -r . \
-	  --xsltproc-opts='--stringparam toc.max.depth 3' \
-	  $<
+.PHONY: all prep chunked xhtml pdf clean
 
-chunked: $(TOPLEVEL_DOC)
-	$(A2X) -d book -f chunked -a lang=ru \
-	  --icons -r $(RESOURCE_FILES) -r . \
-	  --xsltproc-opts='--stringparam toc.max.depth 3' \
-	  $<
+all: chunked xhtml pdf
 
-pdf: $(TOPLEVEL_DOC)
-	$(A2X) --verbose --fop --fop-opts='-c .fop.xconf' -d book -f pdf -a lang=ru \
-	  --xsltproc-opts=' \
-	  --stringparam toc.max.depth 3 \
-	  --stringparam title.font.family "DejaVu Sans" \
-	  --stringparam body.font.family "DejaVu Serif" \
-	  --stringparam monospace.font.family "DejaVu Sans Mono"' \
-	  $<
+prep:
+	@if [ -n "$(BUILDDIR)" ]; then mkdir -p "$(BUILDDIR)"; fi
+
+chunked xhtml: prep
+	@echo "** building $@ book"
+	@$(A2X) -f $@ $(HTML_ARGS)
+
+pdf: prep
+	@echo "** building $@ book"
+	@$(A2X) --xsltproc-opts='$(XSLT_ARGS) \
+		--stringparam title.font.family "DejaVu Sans" \
+		--stringparam body.font.family "DejaVu Serif" \
+		--stringparam monospace.font.family "DejaVu Sans Mono"' \
+		--fop --fop-opts='-c $(FXC)' -f pdf $(COMMON_ARGS)
+
+clean:
+	@echo "** cleaning up"
+	@if [ -d "$(BUILDDIR)" ]; then cd "$(BUILDDIR)"; fi; \
+	rm -f $(PROJECT).pdf $(PROJECT).html docbook-xsl.css; \
+	rm -rf $(PROJECT).chunked/