added: music structs

diff --git a/src/music.rs b/src/music.rs
new file mode 100644 (file)
index 0000000..7fe4d64
--- /dev/null
+++ b/src/music.rs
@@ -0,0 +1,56 @@
+pub type NoteMask = [bool; 12];
+
+pub enum Scale {
+    Ionian,
+    Dorian,
+    Phrygian,
+    Lydian,
+    Mixolydian,
+    Aeolian,
+    Locrian,
+    MajPent,
+    SusEgypt,
+    BlueMajPent,
+    BlueMinPen,
+    MinPent,
+    WholeTone,
+    Chromatic,
+}
+
+impl Scale {
+    pub fn to_notes(&self) -> NoteMask {
+        let mut diatonic: NoteMask = [
+            true, false, true, false, true, true, false, true, false, true, false, true,
+        ];
+
+        let mut pentatonic: NoteMask = [
+            true, false, true, false, true, false, false, true, false, true, false, false,
+        ];
+
+        macro_rules! rotate {
+            ($i:ident,$e:expr) => {{
+                $i.rotate_left($e);
+                $i
+            }};
+        }
+
+        match self {
+            Scale::Ionian => diatonic,
+            Scale::Dorian => rotate!(diatonic, 2),
+            Scale::Phrygian => rotate!(diatonic, 4),
+            Scale::Lydian => rotate!(diatonic, 5),
+            Scale::Mixolydian => rotate!(diatonic, 7),
+            Scale::Aeolian => rotate!(diatonic, 9),
+            Scale::Locrian => rotate!(diatonic, 11),
+            Scale::MajPent => pentatonic,
+            Scale::SusEgypt => rotate!(pentatonic, 2),
+            Scale::BlueMinPen => rotate!(pentatonic, 4),
+            Scale::BlueMajPent => rotate!(pentatonic, 7),
+            Scale::MinPent => rotate!(pentatonic, 9),
+            Scale::Chromatic => [true; 12],
+            Scale::WholeTone => [
+                true, false, true, false, true, false, true, false, true, false, true, false,
+            ],
+        }
+    }
+}