Add the ability to Import a PathWeaver Waypoint file

wpimath/src/main/java/edu/wpi/first/wpilibj/waypoint/WaypointUtil.java

@@ -0,0 +1,123 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj.waypoint;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+import edu.wpi.first.wpilibj.geometry.Pose2d;
+import edu.wpi.first.wpilibj.geometry.Rotation2d;
+import edu.wpi.first.wpilibj.geometry.Translation2d;
+import edu.wpi.first.wpilibj.spline.Spline.ControlVector;
+import edu.wpi.first.wpilibj.trajectory.Trajectory;
+import edu.wpi.first.wpilibj.trajectory.TrajectoryConfig;
+import edu.wpi.first.wpilibj.trajectory.TrajectoryGenerator;
+import edu.wpi.first.wpilibj.trajectory.TrajectoryGenerator.ControlVectorList;
+
+public final class WaypointUtil {
+  private WaypointUtil() {
+    throw new UnsupportedOperationException("This is a utility class!");
+  }
+
+  /**
+   * Imports Path object and creates a trajectory with that info.
+   *
+   * @param filepath Full path to the file
+   * @param config TrajectoryConfig that sets the contraints for the Trajectory to be generated
+   *
+   * @return Trajectory created from the waypoints in the file.
+   */
+  public static Trajectory importPathToCubicTrajectory(String filepath, TrajectoryConfig config) throws IOException {
+    try (FileReader fr = new FileReader(new File(filepath));
+      BufferedReader reader = new BufferedReader(fr)) {
+
+      var interiorWaypoints = new ArrayList<Translation2d>();
+      Pose2d start = new Pose2d();
+      Pose2d end = new Pose2d();
+      int loop = 0;
+      String line;
+      String lastline = "";
+
+      while ((line = reader.readLine()) != null) {
+        if (loop == 0) {
+          if (!line.equals("X,Y,Tangent X,Tangent Y,Fixed Theta,Reversed,Name")) {
+            throw new RuntimeException("this isn’t a PathWeaver csv file");
+          }  
+        }
+        else if (loop == 1) {
+          start = createPoseWaypoint(line);
+        }
+        else if (loop == 2) {
+          ; // skip the second line because we are logging the lastline and at 2 lastline is start
+        }
+        else {
+          interiorWaypoints.add(createTranslationWaypoint(lastline));
+        }
+        lastline = line;
+        loop++;
+      }
+      end = createPoseWaypoint(lastline);
+
+      return TrajectoryGenerator.generateTrajectory(
+            start,
+            interiorWaypoints,
+            end,
+            config);
+    }
+  }
+
+  /**
+   * Imports Path object and creates a trajectory with that info.
+   *
+   * @param filepath Full path to the file
+   * @param config TrajectoryConfig that sets the contraints for the Trajectory to be generated
+   *
+   * @return Trajectory created from the waypoints in the file.
+   */
+  public static Trajectory importPathToQuinticTrajectory(String filepath, TrajectoryConfig config) throws IOException {
+    try (FileReader fr = new FileReader(new File(filepath));
+      BufferedReader reader = new BufferedReader(fr)) {
+
+      ControlVectorList controlVectors = new ControlVectorList();
+      int loop = 0;
+      String line;
+
+      while ((line = reader.readLine()) != null) {
+         if (loop == 0) {
+            if (!line.equals("X,Y,Tangent X,Tangent Y,Fixed Theta,Reversed,Name")) {
+              throw new RuntimeException("this isn’t a PathWeaver csv file");
+            }
+         }
+         else {
+            controlVectors.add(createControlVector(line));
+         }
+         loop++;
+      }
+      return TrajectoryGenerator.generateTrajectory(controlVectors,            
+            config);
+    }
+  }
+
+  private static Pose2d createPoseWaypoint(String input) {
+    String[] arrOfStr = input.split(",", 0);
+    return new Pose2d(new Translation2d(Double.parseDouble(arrOfStr[0]), Double.parseDouble(arrOfStr[1])),
+       new Rotation2d(Double.parseDouble(arrOfStr[2]), Double.parseDouble(arrOfStr[3])));
+  }
+
+  private static Translation2d createTranslationWaypoint(String input) {
+    String[] arrOfStr = input.split(",", 0);
+    return new Translation2d(Double.parseDouble(arrOfStr[0]), Double.parseDouble(arrOfStr[1]));
+  }
+
+  private static ControlVector createControlVector(String input) {
+    String[] arrOfStr = input.split(",", 0);
+    double[] x = new double[] {Double.parseDouble(arrOfStr[0]), Double.parseDouble(arrOfStr[2])};
+    double[] y = new double[] {Double.parseDouble(arrOfStr[1]), Double.parseDouble(arrOfStr[3])};
+    return new ControlVector(x, y);
+  }
+}