Add configuration for Ninja build system

Run configure.py to generate a build.ninja file to build with ninja.

$ ./configure.py
$ ninja

Ninja can also build individual targets, for example

$ ninja bin/libflatland.so
$ ninja bin/test/test1

1 files changed, 45 insertions, 0 deletions

diff --git a/configure.py b/configure.py
new file mode 100755
index 0000000..1cb3fd7
--- /dev/null
+++ b/configure.py
@@ -0,0 +1,45 @@
+#! /usr/bin/env python3
+import os
+import re
+
+def find_sources(path):
+    sources = tuple(filter(lambda f: f.endswith(".cpp"), os.listdir(path)))
+    objects = tuple(map(lambda f: re.sub(".cpp$", ".o", f), sources))
+
+    # add path prefix to files
+    sources = tuple(map(lambda f: path + "/" + f, sources))
+    objects = tuple(map(lambda f: "bin/" + path + "/" + f, objects))
+
+    return sources, objects
+
+
+with open("build.ninja", "w") as bf:
+
+    # find engine sources
+    sources, objects = find_sources("engine")
+
+    # include rules
+    print("include ninja/rules.ninja\n", file=bf)
+
+    # create build directories
+    print("build bin/engine: mkdir\n", file=bf)
+    print("build bin/test: mkdir\n", file=bf)
+
+
+    # build engine files
+    for s, o in zip(sources, objects):
+        print("build {}: cpp {}".format(o, s), file=bf)
+
+    # build engine library
+    print("\nbuild bin/libflatland.so: link-shared " + " ".join(objects) + "\n", file=bf)
+
+
+    # find test sources
+    sources, objects = find_sources("test")
+    binaries = tuple(map(lambda f: re.sub(".o$", "", f), objects))
+
+    # build tests
+    for s, o, b in zip(sources, objects, binaries):
+        print("build {}: cpp {}".format(o, s), file=bf)
+        print("build {}: link {}".format(b, o), file=bf)
+        print("    lflags = $lflags ../bin/libflatland.so\n", file=bf)