refactor(song): Remove song length from Song and assume the user knows MAX_SAMPLES

Trying to force a specific song length other than the default never quite worked, so we'll only support the default MAX_SAMPLES & will calculate it for the user in the user in the exported .h header file.

go4k/asmformat.go

@@ -158,7 +158,7 @@ func DeserializeAsm(asmcode string) (*Song, error) {
 			}
 		}
 	}
-	s := Song{BPM: bpm, Patterns: patterns, Tracks: tracks, Patch: patch, SongLength: -1}
+	s := Song{BPM: bpm, Patterns: patterns, Tracks: tracks, Patch: patch}
 	return &s, nil
 }
 

go4k/song.go

@@ -1,13 +1,15 @@
 package go4k
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 type Song struct {
-	BPM        int
-	Patterns   [][]byte
-	Tracks     []Track
-	SongLength int // in samples, 0 means calculate automatically from BPM and Track lengths, but can also set manually
-	Patch      Patch
+	BPM      int
+	Patterns [][]byte
+	Tracks   []Track
+	Patch    Patch
 }
 
 func (s *Song) PatternRows() int {
@@ -74,13 +76,9 @@ func Play(synth Synth, song Song) ([]float32, error) {
 	for i := range curVoices {
 		curVoices[i] = song.FirstTrackVoice(i)
 	}
-	samples := song.SongLength
-	if samples <= 0 {
-		samples = song.TotalRows() * song.SamplesPerRow()
-	}
-	buffer := make([]float32, samples*2)
-	totaln := 0
-	rowtime := song.SamplesPerRow()
+	initialCapacity := song.TotalRows() * song.SamplesPerRow() * 2
+	buffer := make([]float32, 0, initialCapacity)
+	rowbuffer := make([]float32, song.SamplesPerRow()*2)
 	for row := 0; row < song.TotalRows(); row++ {
 		patternRow := row % song.PatternRows()
 		pattern := row / song.PatternRows()
@@ -100,8 +98,15 @@ func Play(synth Synth, song Song) ([]float32, error) {
 				synth.Trigger(curVoices[t], note)
 			}
 		}
-		samples, _, _ := synth.Render(buffer[2*totaln:], rowtime)
-		totaln += samples
+		tries := 0
+		for rowtime := 0; rowtime < song.SamplesPerRow(); {
+			samples, time, _ := synth.Render(rowbuffer, song.SamplesPerRow()-rowtime)
+			rowtime += time
+			buffer = append(buffer, rowbuffer[:samples*2]...)
+			if tries > 100 {
+				return nil, fmt.Errorf("Song speed modulation likely so slow that row never advances; error at pattern %v, row %v", pattern, patternRow)
+			}
+		}
 	}
 	return buffer, nil
 }

go4k/song_json_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/vsariola/sointu/go4k"
 )
 
-const expectedMarshaled = `{"BPM":100,"Patterns":["QABEACAAAABLAE4AAAAAAA=="],"Tracks":[{"NumVoices":1,"Sequence":"AA=="}],"SongLength":0,"Patch":{"Instruments":[{"NumVoices":1,"Units":[{"Type":"envelope","Parameters":{"attack":32,"decay":32,"gain":128,"release":64,"stereo":0,"sustain":64}},{"Type":"oscillator","Parameters":{"color":96,"detune":64,"flags":64,"gain":128,"phase":0,"shape":64,"stereo":0,"transpose":64}},{"Type":"mulp","Parameters":{"stereo":0}},{"Type":"envelope","Parameters":{"attack":32,"decay":32,"gain":128,"release":64,"stereo":0,"sustain":64}},{"Type":"oscillator","Parameters":{"color":64,"detune":64,"flags":64,"gain":128,"phase":64,"shape":96,"stereo":0,"transpose":72}},{"Type":"mulp","Parameters":{"stereo":0}},{"Type":"out","Parameters":{"gain":128,"stereo":1}}]}],"DelayTimes":[],"SampleOffsets":[]}}`
+const expectedMarshaled = `{"BPM":100,"Patterns":["QABEACAAAABLAE4AAAAAAA=="],"Tracks":[{"NumVoices":1,"Sequence":"AA=="}],"Patch":{"Instruments":[{"NumVoices":1,"Units":[{"Type":"envelope","Parameters":{"attack":32,"decay":32,"gain":128,"release":64,"stereo":0,"sustain":64}},{"Type":"oscillator","Parameters":{"color":96,"detune":64,"flags":64,"gain":128,"phase":0,"shape":64,"stereo":0,"transpose":64}},{"Type":"mulp","Parameters":{"stereo":0}},{"Type":"envelope","Parameters":{"attack":32,"decay":32,"gain":128,"release":64,"stereo":0,"sustain":64}},{"Type":"oscillator","Parameters":{"color":64,"detune":64,"flags":64,"gain":128,"phase":64,"shape":96,"stereo":0,"transpose":72}},{"Type":"mulp","Parameters":{"stereo":0}},{"Type":"out","Parameters":{"gain":128,"stereo":1}}]}],"DelayTimes":[],"SampleOffsets":[]}}`
 
 var testSong = go4k.Song{
 	BPM:      100,
@@ -16,7 +16,6 @@ var testSong = go4k.Song{
 	Tracks: []go4k.Track{
 		{NumVoices: 1, Sequence: []byte{0}},
 	},
-	SongLength: 0,
 	Patch: go4k.Patch{
 		Instruments: []go4k.Instrument{{NumVoices: 1, Units: []go4k.Unit{
 			{"envelope", map[string]int{"stereo": 0, "attack": 32, "decay": 32, "sustain": 64, "release": 64, "gain": 128}},

go4k/song_test.go

@@ -37,7 +37,7 @@ func TestPlayer(t *testing.T) {
 		SampleOffsets: []go4k.SampleOffset{}}
 	patterns := [][]byte{{64, 0, 68, 0, 32, 0, 0, 0, 75, 0, 78, 0, 0, 0, 0, 0}}
 	tracks := []go4k.Track{go4k.Track{1, []byte{0}}}
-	song := go4k.Song{100, patterns, tracks, 0, patch}
+	song := go4k.Song{100, patterns, tracks, patch}
 	synth, err := bridge.Synth(patch)
 	if err != nil {
 		t.Fatalf("Compiling patch failed: %v", err)

go4k/tracker/defaultsong.go

@@ -12,7 +12,6 @@ var defaultSong = go4k.Song{
 		{NumVoices: 1, Sequence: []byte{0}},
 		{NumVoices: 1, Sequence: []byte{1}},
 	},
-	SongLength: 0,
 	Patch: go4k.Patch{
 		Instruments: []go4k.Instrument{{NumVoices: 2, Units: []go4k.Unit{
 			{"envelope", map[string]int{"stereo": 0, "attack": 32, "decay": 32, "sustain": 64, "release": 64, "gain": 128}},

include/sointu/header.inc

@@ -115,7 +115,9 @@ section .text ; yasm throws section redeclaration warnings if strucs are defined
 
 %define TOTAL_ROWS (MAX_PATTERNS*PATTERN_SIZE)
 %define SAMPLES_PER_ROW (SAMPLE_RATE*4*60/(BPM*16))
-%define MAX_SAMPLES (SAMPLES_PER_ROW*TOTAL_ROWS)
+%ifndef MAX_SAMPLES
+    %define MAX_SAMPLES (SAMPLES_PER_ROW*TOTAL_ROWS)
+%endif
 
 %macro BEGIN_PATCH 0
     SECT_DATA(params)

tests/CMakeLists.txt

@@ -159,6 +159,7 @@ target_compile_definitions(test_envelope_16bit PUBLIC SU_USE_16BIT_OUTPUT)
 regression_test(test_polyphony "ENVELOPE;VCO_SINE")
 regression_test(test_chords "ENVELOPE;VCO_SINE")
 regression_test(test_speed "ENVELOPE;VCO_SINE")
+target_compile_definitions(test_speed PUBLIC MAX_SAMPLES=211592)
 
 regression_test(test_render_samples ENVELOPE "" test_render_samples.c)
 target_link_libraries(test_render_samples ${STATICLIB})