add demothemes generator to Makefile

minor improvements

.gitignore

@@ -6,6 +6,17 @@ e2e_report.html
 bin
 out
 d2
+# generated svg examples (from make themesdemo)
+testdata/examples/svg/
 
 # https://github.com/golang/go/blob/8b67cf0bc6ad657fddcbaaa10729d0086f08f9a9/src/cmd/go/internal/test/test.go#L415-L416
-e2etests.test
+e2etests.test
+
+# nix/devenv related
+# .envrc
+devenv.*
+!devenv.nix
+.devenv*
+.direnv
+.pre-commit-config.yaml
+

Makefile

@@ -25,6 +25,18 @@ race: fmt
 js: gen
 	cd d2js/js && NPM_VERSION="${NPM_VERSION}" prefix "$@" ./make.sh all
 
+SVGDIR := testdata/examples/svg
+SVGS = $(shell ./d2 themes | gawk -F':' '/^-/{ printf "$(SVGDIR)/themex-%03d.svg ",$$2 }' || :)
+
+.PHONY: clean
+clean:
+	rm -f $(SVGS) d2
+
 .PHONY: themesdemo
-themesdemo:
-	$(MAKE) -C ./testdata/examples/
+themesdemo: $(SVGS) d2
+
+$(SVGDIR)/themex-%.svg: testdata/examples/themex.d2 
+	$(info Building $@ from $< ...)
+	./d2 -t $$(( 10#$* )) $< $@
+
+# d2: build

testdata/examples/Makefile

@@ -1,14 +0,0 @@
-D2 := ../../d2
-
-SVGS = $(shell $(D2) themes | gawk -F':' '/^-/{ printf "out/themex-%03d.svg ",$$2 }' || :)
-
-.PHONY:
-all: $(D2) $(SVGS)
-
-$(D2):
-	cd $(dir $@) && go build
-	$(MAKE) $(SVGS)
-# D2 as dependency to expire results if recompiled
-out/themex-%.svg: themex.d2 $(D2)
-	$(info Building $@ from $< ...)
-	$(D2) -t $$(( 10#$* )) $< $@