Clean up code and rename to yue

1 files changed, 37 insertions, 0 deletions

diff --git a/yue.scm b/yue.scm
new file mode 100644
index 0000000..6b692ab
--- /dev/null
+++ b/yue.scm
@@ -0,0 +1,37 @@
+(use-modules (ice-9 binary-ports))
+
+; Bitrate is the number time to sample the music function each second
+(define bitrate 8000)
+
+; Triangle wave with a period of 1 second
+(define (tri t)
+	(let ((m (floor-remainder (+ t (/ 1 4)) 1)))
+		(if (< m 1/2)
+			(- (* 4 m) 1)
+			(- 3 (* 4 m)))))
+
+; Square wave with a period of 1 second
+(define (square t)
+	(let ((m (floor-remainder t 1)))
+		(if (< m 0.5) 1 -1)))
+
+; Creates a note
+(define (note freq start len)
+	(lambda (t) (
+		if (or (< t start) (>= t (+ start len)))
+			0
+			(* 1/4 (tri (* t freq))))))
+
+; Gets the frequency of a particular pitch
+(define (getfreq octave pitch)
+	(* 55 (ash 1 octave) (expt 2 (/ pitch 12))))
+
+; Get the music as a list sampled at the bitrate
+(define (play t end)
+	(cons ((lambda (a)
+		(let ((b (modulo (inexact->exact (round (* (+ a 2) 32768))) 65536))) cons
+			(put-u8 (current-output-port) (modulo b 256))
+			(put-u8 (current-output-port) (quotient b 256)))) (music t))
+		(if (< t end)
+			(play (+ t (/ 1 bitrate)) end)
+			'())))