Initial public release: DWG/DXF 2D viewer sample

Standalone Vite sample composing acadrust-dwg WASM, dxf-parser, and Viewer2D.

src/viewer2d/aciColors.js

@@ -0,0 +1,63 @@
+/**
+ * AutoCAD Color Index (ACI) → hex RGB integer.
+ * Returns null for BYBLOCK (0) and BYLAYER (256) — caller uses layer/default color.
+ */
+
+function hsl2hex(h, s, l) {
+  const c = (1 - Math.abs(2 * l - 1)) * s;
+  const x = c * (1 - Math.abs(((h / 60) % 2) - 1));
+  const m = l - c / 2;
+  let r, g, b;
+  if      (h <  60) { r = c; g = x; b = 0; }
+  else if (h < 120) { r = x; g = c; b = 0; }
+  else if (h < 180) { r = 0; g = c; b = x; }
+  else if (h < 240) { r = 0; g = x; b = c; }
+  else if (h < 300) { r = x; g = 0; b = c; }
+  else              { r = c; g = 0; b = x; }
+  return Math.round((r + m) * 255) * 65536
+       + Math.round((g + m) * 255) * 256
+       + Math.round((b + m) * 255);
+}
+
+// ACI 0-9: exact fixed colors
+const FIXED = [
+  null,       // 0: BYBLOCK
+  0xFF0000,   // 1: red
+  0xFFFF00,   // 2: yellow
+  0x00FF00,   // 3: green
+  0x00FFFF,   // 4: cyan
+  0x0000FF,   // 5: blue
+  0xFF00FF,   // 6: magenta
+  0xFFFFFF,   // 7: white
+  0x414141,   // 8: dark gray
+  0x808080,   // 9: gray
+];
+
+// ACI 10-249: 24 hue groups × 10 saturation/lightness variants
+const VARIANTS_SL = [
+  [1.00, 0.50],  // 0: full
+  [1.00, 0.28],  // 1: dark
+  [0.65, 0.65],  // 2: light pastel
+  [0.65, 0.38],  // 3: pastel dark
+  [0.35, 0.80],  // 4: pale
+  [0.35, 0.48],  // 5: pale mid
+  [0.18, 0.68],  // 6: faint light
+  [0.18, 0.38],  // 7: faint dark
+  [0.00, 0.55],  // 8: light gray
+  [0.00, 0.30],  // 9: dark gray
+];
+
+export function aciToHex(aci) {
+  if (aci == null || aci === 0 || aci === 256) return null;
+  if (aci <= 9) return FIXED[aci] ?? null;
+  if (aci >= 250 && aci <= 255) {
+    const v = Math.round(40 + (aci - 250) * 43);
+    return v * 65536 + v * 256 + v;
+  }
+  if (aci >= 10 && aci <= 249) {
+    const idx = aci - 10;
+    const [s, l] = VARIANTS_SL[idx % 10];
+    return hsl2hex(Math.floor(idx / 10) * 15, s, l);
+  }
+  return 0xC9D1D9;
+}