Split into multiple files and rewrite README

5 files changed, 59 insertions, 43 deletions

diff --git a/README.md b/README.md
index adaf2e0..035afd2 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # Lambeat
-Bytebeat in Scheme
+Lambeat is a new way to make music using functional programming. It's heavily influenced by [Bytebeat](https://dollchan.net/bytebeat) and initially started out as an reimplementation of Bytebeat in Scheme. Since then, it's grown to be a delightful new way to make music with code.
 
-You can use `guile main.scm | play -r 8000 -t s16 -v 0.25 -` to try it out.
+## Get started
+First, install [Sox](https://sox.sourceforge.net/) and clone this repo. Write some music in `music.scm`. Enjoy your music with `guile lambeat.scm | play -r 8000 -t s16 -`!
diff --git a/lambeat.scm b/lambeat.scm
new file mode 100644
index 0000000..ac3bb76
--- /dev/null
+++ b/lambeat.scm
@@ -0,0 +1,20 @@
+(use-modules (ice-9 binary-ports))
+(include "music.scm")
+
+(define bitrate 8000)
+
+; Get the music as a list sampled at the bitrate
+(define (play t) (
+	cons (music t) (if (< t 30)
+		(play (+ t (/ 1 bitrate)))
+		'()
+	)
+))
+
+; Output the list in the s16 raw audio format
+(for-each (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))
+)) (play 0))
diff --git a/lib.scm b/lib.scm
new file mode 100644
index 0000000..66d2a0e
--- /dev/null
+++ b/lib.scm
@@ -0,0 +1,18 @@
+(define (saw t) (
+	let ((m (floor-remainder (+ t (/ 1 4)) 1)))
+		(if (< m 1/2)
+			(- (* 4 m) 1)
+			(- 3 (* 4 m)))
+))
+
+(define (note freq start len) (
+	lambda (t) (
+		if (or (< t start) (>= t (+ start len)))
+			0
+			(saw (* freq t))
+	)
+))
+
+(define (getfreq octave pitch) (
+	* 55 (ash 1 octave) (expt 2 (/ pitch 13))
+))
diff --git a/main.scm b/main.scm
deleted file mode 100644
index a3e3788..0000000
--- a/main.scm
+++ /dev/null
@@ -1,41 +0,0 @@
-(use-modules (ice-9 binary-ports))
-
-(define bitrate 8000)
-
-(define (saw t) (
-	let ((m (floor-remainder (+ t (/ 1 4)) 1)))
-		(if (< m 1/2)
-			(- (* 4 m) 1)
-			(- 3 (* 4 m)))
-))
-
-(define (note freq start len) (
-	lambda (t) (
-		if (or (< t start) (>= t (+ start len)))
-			0
-			(saw (* freq t))
-	)
-))
-
-(define (music t) (+
-	((note 523.25 0 1) t)
-	((note 587.33 1 1) t)
-	((note 659.25 2 1) t)
-	((note 698.46 3 1) t)
-	((note 783.99 4 1) t)
-))
-
-(define (play t) (
-	cons (music t) (if (< t 5)
-		(play (+ t (/ 1 bitrate)))
-		'()
-	)
-))
-
-;(display (play 0))
-(for-each (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))
-)) (play 0))
diff --git a/music.scm b/music.scm
new file mode 100644
index 0000000..a45111f
--- /dev/null
+++ b/music.scm
@@ -0,0 +1,18 @@
+(include "lib.scm")
+
+(define (melody t) (+
+	((note (getfreq 3 4) 0 1/4) t)
+	((note (getfreq 3 8) 1/4 1/4) t)
+	((note (getfreq 3 4) 3/4 1/4) t)
+	((note (getfreq 3 11) 1 1/4) t)
+	((note (getfreq 3 4) 5/4 1/4) t)
+	((note (getfreq 3 2) 3/2 1/4) t)
+	((note (getfreq 3 8) 7/4 1/4) t)
+	((note (getfreq 3 4) 9/4 1/4) t)
+	((note (getfreq 3 11) 5/2 1/4) t)
+	((note (getfreq 3 4) 11/4 1/4) t)
+))
+
+(define (music t) (
+	melody (floor-remainder t 3)
+))