Files
analogue_synth/www/bootstrap.js
Matt Spencer c8ef3df460 Add audio nodes to the patch bay
Also make the patch bay responsive.
2026-03-26 08:47:47 +00:00

137 lines
5.4 KiB
JavaScript

/**
* bootstrap.js — ES module entry point.
*
* Initialises the WASM module, wires canvas elements to Rust-exported types,
* keeps canvas drawing buffers in sync with their CSS size, and provides a
* draggable resize handle for the patch bay panel.
*/
import init, {
AudioEngine,
OscilloscopeView,
SpectrumView,
PatchBay,
SynthParams,
} from "./pkg/synth_visualiser.js";
// ── Canvas buffer sizing ──────────────────────────────────────────────────────
// A <canvas> has two independent sizes:
// - CSS display size (width/height CSS properties) — how large it appears
// - Drawing buffer (width/height HTML attributes) — actual pixel resolution
//
// We must keep them in sync; if the buffer is smaller than the display size the
// browser stretches it and everything looks blurry / oversized.
function fitCanvas(canvas) {
const w = Math.round(canvas.clientWidth);
const h = Math.round(canvas.clientHeight);
if (w > 0 && h > 0 && (canvas.width !== w || canvas.height !== h)) {
canvas.width = w;
canvas.height = h;
}
}
// ── Resize handle ─────────────────────────────────────────────────────────────
function initResizeHandle() {
const handle = document.getElementById("resize-handle");
const panel = document.getElementById("patchbay-panel");
let dragging = false;
let startY = 0;
let startH = 0;
handle.addEventListener("pointerdown", e => {
dragging = true;
startY = e.clientY;
startH = panel.offsetHeight;
handle.setPointerCapture(e.pointerId);
handle.classList.add("active");
});
handle.addEventListener("pointermove", e => {
if (!dragging) return;
// Dragging up (negative dy) increases the panel height
const dy = e.clientY - startY;
const h = Math.max(80, startH - dy);
panel.style.height = h + "px";
});
handle.addEventListener("pointerup", () => { dragging = false; handle.classList.remove("active"); });
handle.addEventListener("pointercancel",() => { dragging = false; handle.classList.remove("active"); });
}
// ── Bootstrap ─────────────────────────────────────────────────────────────────
const loader = document.getElementById("loader");
const status = document.getElementById("status");
const srLabel = document.getElementById("sample-rate");
const frameTime = document.getElementById("frame-time");
async function bootstrap() {
initResizeHandle();
try {
await init();
const engine = new AudioEngine();
await engine.attach();
const analyser = engine.analyser_node();
const oscilloscope = new OscilloscopeView("oscilloscope-canvas", analyser);
const spectrum = new SpectrumView("spectrum-canvas", analyser);
const patchbay = new PatchBay("patchbay-canvas");
// Fit all canvas buffers to their current CSS layout size before we
// ask Rust for canvas.width() to position the default modules.
const pbCanvas = document.getElementById("patchbay-canvas");
const oscCanvas = document.getElementById("oscilloscope-canvas");
const specCanvas = document.getElementById("spectrum-canvas");
const allCanvases = [oscCanvas, specCanvas, pbCanvas];
allCanvases.forEach(fitCanvas);
// Seed a default patch using the now-correct canvas width.
const cw = pbCanvas.width || pbCanvas.clientWidth || 800;
patchbay.add_module("vco", cw * 0.12, 80);
patchbay.add_module("adsr", cw * 0.32, 80);
patchbay.add_module("svf", cw * 0.55, 80);
patchbay.add_module("vca", cw * 0.76, 80);
// Keep canvas buffers in sync whenever the panel is resized.
const ro = new ResizeObserver(() => allCanvases.forEach(fitCanvas));
allCanvases.forEach(c => ro.observe(c));
// Patch bay pointer events
pbCanvas.addEventListener("pointerdown", e => patchbay.on_pointer_down(e.offsetX, e.offsetY));
pbCanvas.addEventListener("pointermove", e => patchbay.on_pointer_move(e.offsetX, e.offsetY));
pbCanvas.addEventListener("pointerup", e => patchbay.on_pointer_up(e.offsetX, e.offsetY));
pbCanvas.addEventListener("dblclick", e => patchbay.on_double_click(e.offsetX, e.offsetY));
const params = new SynthParams();
engine.set_params(params.to_json());
srLabel.textContent = `SR: ${engine.sample_rate()} Hz`;
status.textContent = "Running";
engine.start();
let last = performance.now();
function frame(now) {
oscilloscope.draw();
spectrum.draw();
patchbay.draw();
frameTime.textContent = `frame: ${(now - last).toFixed(1)} ms`;
last = now;
requestAnimationFrame(frame);
}
requestAnimationFrame(frame);
loader.classList.add("hidden");
} catch (err) {
console.error("[bootstrap] Fatal:", err);
loader.textContent = `Error: ${err.message ?? err}`;
}
}
bootstrap();