Release God's Eye View as open source

src/data/cockpitContactDot.js

@@ -0,0 +1,44 @@
+/**
+ * Lazily create the shared white contact pip used by aircraft layers while the
+ * first-person cockpit is active. Cesium multiplies this white texture by the
+ * billboard color, so civilian and military owners retain their provenance
+ * colors without maintaining separate image assets.
+ *
+ * @returns {string} One stable data-URL identity shared by every billboard.
+ */
+export function cockpitContactDotImage() {
+  if (cockpitContactDotImage._dataUrl) return cockpitContactDotImage._dataUrl;
+
+  const canvas = document.createElement('canvas');
+  canvas.width = 16;
+  canvas.height = 16;
+  const ctx = canvas.getContext('2d');
+  ctx.clearRect(0, 0, 16, 16);
+
+  // Match the visor's fine-line symbology: a restrained luminous ring with a
+  // crisp center fix, rather than a solid map-marker blob. The layer tint
+  // supplies civilian cyan-white or military amber provenance.
+  ctx.save();
+  ctx.shadowBlur = 2.5;
+  ctx.shadowColor = 'rgba(255, 255, 255, 0.55)';
+  ctx.beginPath();
+  ctx.arc(8, 8, 4.25, 0, Math.PI * 2);
+  ctx.lineWidth = 1.25;
+  ctx.strokeStyle = 'rgba(255, 255, 255, 0.82)';
+  ctx.stroke();
+  ctx.shadowBlur = 1.5;
+  ctx.beginPath();
+  ctx.arc(8, 8, 1.55, 0, Math.PI * 2);
+  ctx.fillStyle = 'rgba(255, 255, 255, 0.98)';
+  ctx.fill();
+  ctx.restore();
+
+  // Billboard.image assigns a fresh texture-atlas id to non-string sources.
+  // Returning the same canvas for hundreds of contacts therefore still made
+  // Cesium upload/repack hundreds of identical textures at cockpit entry.
+  // A stable URL is keyed once and shared by the entire fleet.
+  cockpitContactDotImage._dataUrl = canvas.toDataURL('image/png');
+  return cockpitContactDotImage._dataUrl;
+}
+
+cockpitContactDotImage._dataUrl = null;