21 files changed, 117 insertions, 36 deletions
diff --git a/.gitignore b/.gitignore
index a6a369a..51d2952 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.pyc
 *.dxf
 *.stl
+*.d
diff --git a/Makefile b/Makefile
index 1b50f45..c91ea47 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,11 @@
 INKSCAPE ?= inkscape
 OPENSCAD ?= openscad
+PYTHON ?= python2
+
+PYTHON_CMD := PYTHONPATH="support:$$PYTHONPATH" $(PYTHON)
 
 # Used by dxf_export/main.sh
-export INKSCAPE
+export INKSCAPE OPENSCAD
 
 # Run generate_scad.sh to get the names of all OpenSCAD files that should be generated using that same script.
 GENERATED_FILES := $(addsuffix .scad,$(basename $(shell ./generate_sources.sh)))
@@ -13,34 +16,32 @@ GENERATED_SCAD_FILES := $(filter %.scad, $(GENERATED_FILES))
 SVG_FILES := $(shell find src -name '*.svg') $(GENERATED_SVG_FILES)
 
 # Only OpenSCAD files whose names do not start with `_' are compiled to STL.
-SCAD_FILES := $(shell find src -name '*.scad') $(GENERATED_SCAD_FILES)
-LIBRARY_SCAD_FILES := $(foreach i,$(SCAD_FILES),$(if $(filter _%,$(notdir $(i))),$(i)))  
-COMPILED_SCAD_FILES := $(filter-out $(LIBRARY_SCAD_FILES),$(SCAD_FILES))
+COMPILED_SCAD_FILES := $(foreach i,$(shell find src -name '*.scad') $(GENERATED_SCAD_FILES),$(if $(filter-out _%,$(notdir $(i))),$(i)))
+
+# Makefiles which are generated while compiling to record dependencies.
+DEPENDENCY_FILES := $(patsubst %.scad,%.d,$(COMPILED_SCAD_FILES))
 
 # All files that may be generated from the source files.
 STL_FILES := $(patsubst %.scad,%.stl,$(COMPILED_SCAD_FILES))
 DXF_FILES := $(patsubst %.svg,%.dxf,$(SVG_FILES))
 
 # Everything. Also generates files which aren't compiled to anything else.
-all: $(STL_FILES) $(GENERATED_FILES)
+all: $(GENERATED_FILES) $(DXF_FILES) $(STL_FILES)
 
 # Everything^-1.
 clean:
-	rm -rf $(DXF_FILES) $(STL_FILES) $(GENERATED_FILES)
-
-# Needs to be included after target all has been defined.
--include config.mk
+	rm -rf $(GENERATED_FILES) $(DXF_FILES) $(STL_FILES) $(DEPENDENCY_FILES)
 
-# Assume that any compiled OpenSCAD file may depend on any non-compiled OpenSCAD file in the same directory.
-$(foreach i,$(COMPILED_SCAD_FILES),$(eval $(i): $(filter $(dir $(i))%,$(LIBRARY_SCAD_FILES) $(DXF_FILES))))
+# Include the local configuration file and the dependency files. Needs to be included after the `all' target has been defined.
+-include config.mk $(DEPENDENCY_FILES)
 
 # Rule to convert an SVG file to a DXF file.
 %.dxf: %.svg
-	python2 dxf_export $< $@
+	$(PYTHON_CMD) -m dxf_export $< $@
 
-# Rule to compile an OpenSCAD file to an STL file.
-%.stl: %.scad
-	$(OPENSCAD) -o $@ $<
+# Rule to compile an OpenSCAD file to an STL file. We require all DXF files to exist before an OpenSCAD file can be used to generate an STL file. Additional dependencies are read from the included makefiles generated during compiling.
+%.stl: %.scad  | $(DXF_FILES)
+	$(PYTHON_CMD) -m openscad $< $@ $*.d
 
 # Rule for automaticlaly generated OpenSCAD files.
 $(GENERATED_FILES): generate_sources.sh
diff --git a/src/_settings.scad b/src/_settings.scad
new file mode 100644
index 0000000..1f84b17
--- /dev/null
+++ b/src/_settings.scad
@@ -0,0 +1,2 @@
+plate_height = 2;
+struts_height = 1;
diff --git a/src/example_1.scad b/src/example_1.scad
new file mode 100644
index 0000000..b6e8931
--- /dev/null
+++ b/src/example_1.scad
@@ -0,0 +1,6 @@
+include <_settings.scad>
+
+render(convexity = 10) {
+	linear_extrude(plate_height)
+		import("example.dxf", layer = "text");
+}
diff --git a/src/example_2.scad b/src/example_2.scad
new file mode 100644
index 0000000..2dd57e6
--- /dev/null
+++ b/src/example_2.scad
@@ -0,0 +1,14 @@
+include <_settings.scad>
+
+render(convexity = 10) {
+	union() {
+		linear_extrude(plate_height)
+			difference() {
+				import("example.dxf", layer = "base");
+				import("example.dxf", layer = "text");
+			}
+		
+		linear_extrude(struts_height)
+			import("example.dxf", layer = "struts");
+	}
+}
diff --git a/support/dxf_export/__init__.py b/support/dxf_export/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/support/dxf_export/__init__.py
diff --git a/dxf_export/__main__.py b/support/dxf_export/__main__.py
index ea6c7ad..76c2121 100644
--- a/dxf_export/__main__.py
+++ b/support/dxf_export/__main__.py
@@ -1,15 +1,6 @@
-import sys, os, xml.etree.ElementTree, subprocess, tempfile, contextlib, shutil
-import better_dxf_outlines
-
-
-@contextlib.contextmanager
-def TemporaryDirectory():
-	dir = tempfile.mkdtemp()
-	
-	try:
-		yield dir
-	finally:
-		shutil.rmtree(dir)
+import sys, os, xml.etree.ElementTree, shutil
+from lib import util
+from . import better_dxf_outlines
 
 
 def _export_dxf(in_path, out_path):
@@ -28,13 +19,6 @@ def _get_inkscape_layer_count(svg_path):
 	return len(layers)
 
 
-def _command(args):
-	process = subprocess.Popen(args)
-	process.wait()
-	
-	assert not process.returncode
-
-
 def _inkscape(svg_path, verbs):
 	def iter_args():
 		yield os.environ['INKSCAPE']
@@ -45,7 +29,7 @@ def _inkscape(svg_path, verbs):
 		
 		yield svg_path
 	
-	_command(list(iter_args()))
+	util.command(list(iter_args()))
 
 
 def _unfuck_svg_document(temp_svg_path):
@@ -82,7 +66,7 @@ def _unfuck_svg_document(temp_svg_path):
 
 
 def main(in_path, out_path):
-	with TemporaryDirectory() as temp_dir:
+	with util.TemporaryDirectory() as temp_dir:
 		temp_svg_path = os.path.join(temp_dir, 'temp.svg')
 		
 		shutil.copyfile(in_path, temp_svg_path)
diff --git a/dxf_export/better_dxf_outlines.py b/support/dxf_export/better_dxf_outlines.py
index 19ec6c8..19ec6c8 100755
--- a/dxf_export/better_dxf_outlines.py
+++ b/support/dxf_export/better_dxf_outlines.py
diff --git a/dxf_export/bezmisc.py b/support/dxf_export/bezmisc.py
index e663fa6..e663fa6 100755
--- a/dxf_export/bezmisc.py
+++ b/support/dxf_export/bezmisc.py
diff --git a/dxf_export/cspsubdiv.py b/support/dxf_export/cspsubdiv.py
index c34236a..c34236a 100755
--- a/dxf_export/cspsubdiv.py
+++ b/support/dxf_export/cspsubdiv.py
diff --git a/dxf_export/cubicsuperpath.py b/support/dxf_export/cubicsuperpath.py
index af61acb..af61acb 100755
--- a/dxf_export/cubicsuperpath.py
+++ b/support/dxf_export/cubicsuperpath.py
diff --git a/dxf_export/dxf_templates.py b/support/dxf_export/dxf_templates.py
index fb26632..fb26632 100755
--- a/dxf_export/dxf_templates.py
+++ b/support/dxf_export/dxf_templates.py
diff --git a/dxf_export/ffgeom.py b/support/dxf_export/ffgeom.py
index 1983586..1983586 100755
--- a/dxf_export/ffgeom.py
+++ b/support/dxf_export/ffgeom.py
diff --git a/dxf_export/inkex.py b/support/dxf_export/inkex.py
index e487822..e487822 100755
--- a/dxf_export/inkex.py
+++ b/support/dxf_export/inkex.py
diff --git a/dxf_export/simplepath.py b/support/dxf_export/simplepath.py
index f62b1b4..f62b1b4 100755
--- a/dxf_export/simplepath.py
+++ b/support/dxf_export/simplepath.py
diff --git a/dxf_export/simplestyle.py b/support/dxf_export/simplestyle.py
index 3ec971e..3ec971e 100755
--- a/dxf_export/simplestyle.py
+++ b/support/dxf_export/simplestyle.py
diff --git a/dxf_export/simpletransform.py b/support/dxf_export/simpletransform.py
index 47cc61e..47cc61e 100755
--- a/dxf_export/simpletransform.py
+++ b/support/dxf_export/simpletransform.py
diff --git a/support/lib/__init__.py b/support/lib/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/support/lib/__init__.py
diff --git a/support/lib/util.py b/support/lib/util.py
new file mode 100644
index 0000000..bede240
--- /dev/null
+++ b/support/lib/util.py
@@ -0,0 +1,36 @@
+import contextlib, subprocess, tempfile, shutil, re, os
+
+
+@contextlib.contextmanager
+def TemporaryDirectory():
+	dir = tempfile.mkdtemp()
+	
+	try:
+		yield dir
+	finally:
+		shutil.rmtree(dir)
+
+
+def command(args):
+	process = subprocess.Popen(args)
+	process.wait()
+	
+	assert not process.returncode
+
+
+def bash_escape_string(string):
+	return "'{}'".format(re.sub("'", "'\"'\"'", string))	
+
+
+def write_file(path, data):
+	temp_path = path + '~'
+	
+	with open(temp_path, 'wb') as file:
+		file.write(data)
+	
+	os.rename(temp_path, path)
+
+
+def read_file(path):
+	with open(path, 'rb') as file:
+		return file.read()
diff --git a/support/openscad/__init__.py b/support/openscad/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/support/openscad/__init__.py
diff --git a/support/openscad/__main__.py b/support/openscad/__main__.py
new file mode 100644
index 0000000..08b2ab6
--- /dev/null
+++ b/support/openscad/__main__.py
@@ -0,0 +1,37 @@
+import os, sys
+from lib import util
+
+
+def _openscad(in_path, out_path, deps_path):
+	util.command([os.environ['OPENSCAD'], '-o', out_path, '-d', deps_path, in_path])
+
+
+def _write_dependencies(path, target, dependencies):
+	util.write_file(path, '{}: {}\n'.format(target, ' '.join(dependencies)).encode())
+
+
+def main(in_path, out_path, deps_path):
+	cwd = os.getcwd()
+	
+	def relpath(path):
+		return os.path.relpath(path, cwd)
+	
+	with util.TemporaryDirectory() as temp_dir:
+		temp_deps_path = os.path.join(temp_dir, 'deps')
+		temp_mk_path = os.path.join(temp_dir, 'mk')
+		temp_files_path = os.path.join(temp_dir, 'files')
+		
+		_openscad(in_path, out_path, temp_deps_path)
+		
+		mk_content = '%:; echo "$@" >> {}'.format(util.bash_escape_string(temp_files_path))
+		
+		util.write_file(temp_mk_path, mk_content.encode())
+		util.command(['make', '-s', '-B', '-f', temp_mk_path, '-f', temp_deps_path])
+		
+		deps = set(map(relpath, util.read_file(temp_files_path).decode().splitlines()))
+		ignored_files = set(map(relpath, [temp_deps_path, temp_mk_path, in_path, out_path]))
+		
+		_write_dependencies(deps_path, relpath(out_path), deps - ignored_files)
+
+
+main(*sys.argv[1:])