sfx-maker: sfxc - sfxr-style .sfx text presets -> 16-bit WAV synthesis
- waves: square (duty), saw, sine, triangle, pitched noise (seeded, deterministic) - envelope attack/sustain/decay, freq slide, vibrato, arpeggio jump, one-pole low/high-pass filters, clamped output - presets blip/coin/explosion/hurt/jump/laser/powerup with seeded variants; preset writes editable .sfx or renders .wav directly - go tests: parse/validate, determinism, per-preset RMS, WAV header roundtrip Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmdG9GqfSWCzts7AkDwRDh
This commit is contained in:
223
sfx-maker/sfx/params.go
Normal file
223
sfx-maker/sfx/params.go
Normal file
@@ -0,0 +1,223 @@
|
||||
// Package sfx synthesizes retro game sound effects (sfxr-style) from
|
||||
// text parameter files and renders them to 16-bit mono WAV.
|
||||
package sfx
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"fmt"
|
||||
"io"
|
||||
"os"
|
||||
"path/filepath"
|
||||
"strconv"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// Params describes one sound effect. Zero values mean "off" for the
|
||||
// optional effects; Defaults() fills the required fields.
|
||||
type Params struct {
|
||||
Name string
|
||||
Wave string // square | saw | sine | triangle | noise
|
||||
|
||||
Volume float64 // 0..1 master gain
|
||||
|
||||
// envelope, seconds
|
||||
Attack float64 // 0 -> Volume
|
||||
Sustain float64 // hold at Volume
|
||||
Decay float64 // Volume -> 0
|
||||
|
||||
Freq float64 // start frequency, Hz
|
||||
FreqSlide float64 // Hz per second, may be negative
|
||||
FreqMin float64 // clamp; sound stops below this (default 20 Hz)
|
||||
|
||||
Duty float64 // square wave duty cycle 0.05..0.95 (default 0.5)
|
||||
|
||||
VibratoDepth float64 // Hz
|
||||
VibratoRate float64 // Hz
|
||||
|
||||
ArpFactor float64 // frequency multiplier applied at ArpTime (0 = off)
|
||||
ArpTime float64 // seconds
|
||||
|
||||
LowPass float64 // cutoff Hz (0 = off)
|
||||
HighPass float64 // cutoff Hz (0 = off)
|
||||
|
||||
SampleRate int // default 44100
|
||||
Seed int64 // noise seed (default 1)
|
||||
}
|
||||
|
||||
// Defaults returns a Params with sensible base values.
|
||||
func Defaults() Params {
|
||||
return Params{
|
||||
Wave: "square",
|
||||
Volume: 0.7,
|
||||
Attack: 0.01,
|
||||
Sustain: 0.1,
|
||||
Decay: 0.15,
|
||||
Freq: 440,
|
||||
FreqMin: 20,
|
||||
Duty: 0.5,
|
||||
SampleRate: 44100,
|
||||
Seed: 1,
|
||||
}
|
||||
}
|
||||
|
||||
// Duration is the total length of the sound in seconds.
|
||||
func (p *Params) Duration() float64 { return p.Attack + p.Sustain + p.Decay }
|
||||
|
||||
// Validate checks ranges and returns a helpful error.
|
||||
func (p *Params) Validate() error {
|
||||
switch p.Wave {
|
||||
case "square", "saw", "sine", "triangle", "noise":
|
||||
default:
|
||||
return fmt.Errorf("wave %q must be square, saw, sine, triangle or noise", p.Wave)
|
||||
}
|
||||
if p.Volume < 0 || p.Volume > 1 {
|
||||
return fmt.Errorf("volume %g out of range 0-1", p.Volume)
|
||||
}
|
||||
if p.Attack < 0 || p.Sustain < 0 || p.Decay < 0 {
|
||||
return fmt.Errorf("attack/sustain/decay must be >= 0")
|
||||
}
|
||||
if p.Duration() <= 0 {
|
||||
return fmt.Errorf("total duration is 0 — set attack, sustain and/or decay")
|
||||
}
|
||||
if p.Duration() > 10 {
|
||||
return fmt.Errorf("total duration %.2fs is too long (max 10s)", p.Duration())
|
||||
}
|
||||
if p.Wave != "noise" && (p.Freq <= 0 || p.Freq > 20000) {
|
||||
return fmt.Errorf("freq %g out of range 1-20000 Hz", p.Freq)
|
||||
}
|
||||
if p.Duty < 0.05 || p.Duty > 0.95 {
|
||||
return fmt.Errorf("duty %g out of range 0.05-0.95", p.Duty)
|
||||
}
|
||||
if p.SampleRate < 8000 || p.SampleRate > 96000 {
|
||||
return fmt.Errorf("sample-rate %d out of range 8000-96000", p.SampleRate)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// ParseFile reads a .sfx file; the name defaults to the file name.
|
||||
func ParseFile(path string) (*Params, error) {
|
||||
f, err := os.Open(path)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer f.Close()
|
||||
p, err := Parse(f)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("%s: %w", path, err)
|
||||
}
|
||||
if p.Name == "" {
|
||||
p.Name = strings.TrimSuffix(filepath.Base(path), filepath.Ext(path))
|
||||
}
|
||||
return p, nil
|
||||
}
|
||||
|
||||
// Parse reads the .sfx text format: one "key: value" per line,
|
||||
// '#' comments. Unknown keys are errors so typos surface immediately.
|
||||
func Parse(r io.Reader) (*Params, error) {
|
||||
p := Defaults()
|
||||
sc := bufio.NewScanner(r)
|
||||
lineNo := 0
|
||||
for sc.Scan() {
|
||||
lineNo++
|
||||
line := strings.TrimSpace(sc.Text())
|
||||
if line == "" || strings.HasPrefix(line, "#") {
|
||||
continue
|
||||
}
|
||||
i := strings.Index(line, ":")
|
||||
if i < 0 {
|
||||
return nil, fmt.Errorf("line %d: want 'key: value', got %q", lineNo, line)
|
||||
}
|
||||
key := strings.ToLower(strings.TrimSpace(line[:i]))
|
||||
val := strings.TrimSpace(line[i+1:])
|
||||
if j := strings.Index(val, " #"); j >= 0 { // trailing comment
|
||||
val = strings.TrimSpace(val[:j])
|
||||
}
|
||||
var err error
|
||||
switch key {
|
||||
case "sfx", "name":
|
||||
p.Name = val
|
||||
case "wave":
|
||||
p.Wave = strings.ToLower(val)
|
||||
case "volume":
|
||||
p.Volume, err = strconv.ParseFloat(val, 64)
|
||||
case "attack":
|
||||
p.Attack, err = strconv.ParseFloat(val, 64)
|
||||
case "sustain":
|
||||
p.Sustain, err = strconv.ParseFloat(val, 64)
|
||||
case "decay":
|
||||
p.Decay, err = strconv.ParseFloat(val, 64)
|
||||
case "freq":
|
||||
p.Freq, err = strconv.ParseFloat(val, 64)
|
||||
case "freq-slide":
|
||||
p.FreqSlide, err = strconv.ParseFloat(val, 64)
|
||||
case "freq-min":
|
||||
p.FreqMin, err = strconv.ParseFloat(val, 64)
|
||||
case "duty":
|
||||
p.Duty, err = strconv.ParseFloat(val, 64)
|
||||
case "vibrato-depth":
|
||||
p.VibratoDepth, err = strconv.ParseFloat(val, 64)
|
||||
case "vibrato-rate":
|
||||
p.VibratoRate, err = strconv.ParseFloat(val, 64)
|
||||
case "arpeggio":
|
||||
p.ArpFactor, err = strconv.ParseFloat(val, 64)
|
||||
case "arpeggio-time":
|
||||
p.ArpTime, err = strconv.ParseFloat(val, 64)
|
||||
case "lowpass":
|
||||
p.LowPass, err = strconv.ParseFloat(val, 64)
|
||||
case "highpass":
|
||||
p.HighPass, err = strconv.ParseFloat(val, 64)
|
||||
case "sample-rate":
|
||||
p.SampleRate, err = strconv.Atoi(val)
|
||||
case "seed":
|
||||
p.Seed, err = strconv.ParseInt(val, 10, 64)
|
||||
default:
|
||||
return nil, fmt.Errorf("line %d: unknown key %q", lineNo, key)
|
||||
}
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("line %d: %s: bad value %q", lineNo, key, val)
|
||||
}
|
||||
}
|
||||
if err := sc.Err(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if err := p.Validate(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &p, nil
|
||||
}
|
||||
|
||||
// Write renders the params back to the .sfx text format (used by the
|
||||
// preset generator so agents get an editable file).
|
||||
func (p *Params) Write(w io.Writer, comment string) error {
|
||||
bw := bufio.NewWriter(w)
|
||||
if comment != "" {
|
||||
fmt.Fprintf(bw, "# %s\n", comment)
|
||||
}
|
||||
fmt.Fprintf(bw, "sfx: %s\nwave: %s\nvolume: %g\n", p.Name, p.Wave, p.Volume)
|
||||
fmt.Fprintf(bw, "attack: %g\nsustain: %g\ndecay: %g\n", p.Attack, p.Sustain, p.Decay)
|
||||
if p.Wave != "noise" {
|
||||
fmt.Fprintf(bw, "freq: %g\n", p.Freq)
|
||||
}
|
||||
if p.FreqSlide != 0 {
|
||||
fmt.Fprintf(bw, "freq-slide: %g\n", p.FreqSlide)
|
||||
}
|
||||
if p.Wave == "square" && p.Duty != 0.5 {
|
||||
fmt.Fprintf(bw, "duty: %g\n", p.Duty)
|
||||
}
|
||||
if p.VibratoDepth > 0 && p.VibratoRate > 0 {
|
||||
fmt.Fprintf(bw, "vibrato-depth: %g\nvibrato-rate: %g\n", p.VibratoDepth, p.VibratoRate)
|
||||
}
|
||||
if p.ArpFactor != 0 {
|
||||
fmt.Fprintf(bw, "arpeggio: %g\narpeggio-time: %g\n", p.ArpFactor, p.ArpTime)
|
||||
}
|
||||
if p.LowPass > 0 {
|
||||
fmt.Fprintf(bw, "lowpass: %g\n", p.LowPass)
|
||||
}
|
||||
if p.HighPass > 0 {
|
||||
fmt.Fprintf(bw, "highpass: %g\n", p.HighPass)
|
||||
}
|
||||
if p.Seed != 1 {
|
||||
fmt.Fprintf(bw, "seed: %d\n", p.Seed)
|
||||
}
|
||||
return bw.Flush()
|
||||
}
|
||||
Reference in New Issue
Block a user