Update distance unit to LAMMPS setting

cpp/lammpsweb/lammpsweb.cpp

@@ -366,6 +366,13 @@ std::string LAMMPSWeb::getLastCommand() {
   return lastCommand;
 }
 
+std::string LAMMPSWeb::getUnits() {
+  if (!m_lmp || !m_lmp->update) {
+    return "";
+  }
+  return std::string(m_lmp->update->unit_style);
+}
+
 
 int LAMMPSWeb::getTimesteps() {
   if (!m_lmp) {

cpp/lammpsweb/lammpsweb.h

@@ -59,6 +59,7 @@ class LAMMPSWeb
   Fix getFix(std::string name);
   std::vector<std::string> getVariableNames();
   Variable getVariable(std::string name);
+  std::string getUnits();
   long getMemoryUsage();
 
   // Pointer getters
@@ -121,6 +122,7 @@ EMSCRIPTEN_BINDINGS(LAMMPSWeb)
     .function("getFixNames", &LAMMPSWeb::getFixNames)
     .function("getVariable", &LAMMPSWeb::getVariable)
     .function("getVariableNames", &LAMMPSWeb::getVariableNames)
+    .function("getUnits", &LAMMPSWeb::getUnits)
     .function("syncComputes", &LAMMPSWeb::syncComputes)
     .function("syncFixes", &LAMMPSWeb::syncFixes)
     .function("syncVariables", &LAMMPSWeb::syncVariables)

src/components/SelectedAtomsInfo.tsx

@@ -1,6 +1,7 @@
 import { Button } from "antd";
 import { Particles } from "omovi";
 import { useMemo } from "react";
+import { useLammpsUnits } from "../hooks/useLammpsUnits";
 
 interface SelectedAtomsInfoProps {
   selectedAtoms: Set<number>;
@@ -48,6 +49,8 @@ const SelectedAtomsInfo = ({
   particles,
   onClearSelection,
 }: SelectedAtomsInfoProps) => {
+  const distanceUnit = useLammpsUnits();
+
   if (selectedAtoms.size === 0) {
     return null;
   }
@@ -117,7 +120,7 @@ const SelectedAtomsInfo = ({
             Geometry
           </div>
           <div style={{ fontFamily: "monospace", fontSize: "11px" }}>
-            Distance: {calculateDistance(atomData[0].position, atomData[1].position).toFixed(3)} Å
+            Distance: {calculateDistance(atomData[0].position, atomData[1].position).toFixed(3)} {distanceUnit}
           </div>
         </div>
       )}
@@ -130,15 +133,15 @@ const SelectedAtomsInfo = ({
           </div>
           <div style={{ fontFamily: "monospace", fontSize: "11px" }}>
             d({atomData[0].atomId}-{atomData[1].atomId}):{" "}
-            {calculateDistance(atomData[0].position, atomData[1].position).toFixed(3)} Å
+            {calculateDistance(atomData[0].position, atomData[1].position).toFixed(3)} {distanceUnit}
           </div>
           <div style={{ fontFamily: "monospace", fontSize: "11px" }}>
             d({atomData[1].atomId}-{atomData[2].atomId}):{" "}
-            {calculateDistance(atomData[1].position, atomData[2].position).toFixed(3)} Å
+            {calculateDistance(atomData[1].position, atomData[2].position).toFixed(3)} {distanceUnit}
           </div>
           <div style={{ fontFamily: "monospace", fontSize: "11px" }}>
             d({atomData[0].atomId}-{atomData[2].atomId}):{" "}
-            {calculateDistance(atomData[0].position, atomData[2].position).toFixed(3)} Å
+            {calculateDistance(atomData[0].position, atomData[2].position).toFixed(3)} {distanceUnit}
           </div>
           <div style={{ marginTop: "5px" }}>
             <div style={{ fontFamily: "monospace", fontSize: "11px" }}>

src/hooks/useLammpsUnits.ts

@@ -0,0 +1,20 @@
+import { useMemo } from "react";
+import { useStoreState } from "./index";
+import { getDistanceUnitSymbol } from "../utils/parsers";
+
+/**
+ * Hook to get the distance unit symbol based on the current LAMMPS unit system
+ * @returns The distance unit symbol (e.g., "Å", "σ", "m", "cm", etc.)
+ */
+export const useLammpsUnits = (): string => {
+  const lammps = useStoreState((state) => state.simulation.lammps);
+
+  return useMemo(() => {
+    if (!lammps) {
+      return "Å"; // Default to Angstroms if LAMMPS is not available
+    }
+
+    const unitStyle = lammps.getUnits();
+    return getDistanceUnitSymbol(unitStyle);
+  }, [lammps]);
+};

src/types.ts

@@ -17,6 +17,7 @@ export type LammpsWeb = {
   getFixNames: () => CPPArray<string>;
   getVariable: (name: string) => LMPModifier;
   getVariableNames: () => CPPArray<string>;
+  getUnits: () => string;
   syncComputes: () => void;
   syncFixes: () => void;
   syncVariables: () => void;

src/utils/parsers.ts

@@ -88,3 +88,35 @@ export const parseAtomSizeAndColor = (line: string) => {
   }
 };
 
+/**
+ * Gets the distance unit symbol for a given LAMMPS unit style
+ * @param unitStyle The LAMMPS unit style (e.g., "real", "metal", "lj", "si", etc.)
+ * @returns The distance unit symbol string
+ */
+export const getDistanceUnitSymbol = (unitStyle: string | undefined): string => {
+  if (!unitStyle) {
+    return "Å"; // Default to Angstroms if unit style is not found
+  }
+
+  const style = unitStyle.toLowerCase();
+  switch (style) {
+    case "lj":
+      return "σ";
+    case "real":
+    case "metal":
+      return "Å";
+    case "si":
+      return "m";
+    case "cgs":
+      return "cm";
+    case "electron":
+      return "a₀";
+    case "micro":
+      return "μm";
+    case "nano":
+      return "nm";
+    default:
+      return "Å"; // Default to Angstroms for unknown unit styles
+  }
+};
+