1 files changed, 33 insertions, 0 deletions
diff --git a/lib/time.moon b/lib/time.moon
new file mode 100644
index 0000000..f2ad70c
--- /dev/null
+++ b/lib/time.moon
@@ -0,0 +1,33 @@
+import Op, Const from require 'base'
+
+class lfo extends Op
+  tau = math.pi * 2
+  new: (...) =>
+    super ...
+    @phase = 0
+
+  setup: (@freq, @wave=Const 'sin') =>
+
+  update: (dt) =>
+    @phase += dt * @freq\get!
+    @value = switch @wave\get!
+      when 'sin' then .5 + .5 * math.cos @phase * tau
+      when 'saw' then @phase % 1
+      when 'tri' then math.abs (2*@phase % 2) - 1
+      else error "unknown wave type"
+
+class tick extends Op
+  new: (...) =>
+    super ...
+    @phase = 0
+
+  setup: (@freq) =>
+
+  update: (dt) =>
+    @phase += dt / @freq\get!
+    @value = math.floor @phase
+
+{
+  :lfo
+  :tick
+}