Twist

数据结构

字节索引	类型	字段含义
0-7	float64	X 轴线速度
8-15	float64	Y 轴线速度
16-23	float64	Z 轴线速度
24-31	float64	X 轴角速度
32-39	float64	Y 轴角速度
40-47	float64	Z 轴角速度

Twist 固定为 48 字节

示例

C++ 示例

struct Vector3 {
  double x;
  double y;
  double z;
};

struct Twist {
  Vector3 linear;
  Vector3 angular;
};

Rust 示例

#[repr(C)]
#[derive(Clone, Copy, Debug, Default)]
pub struct Vector3 {
    pub x: f64,
    pub y: f64,
    pub z: f64,
}

#[repr(C)]
#[derive(Clone, Copy, Debug, Default)]
pub struct Twist {
    pub linear: Vector3,
    pub angular: Vector3,
}

const _: () = {
    assert!(core::mem::size_of::<Vector3>() == 24);
    assert!(core::mem::size_of::<Twist>() == 48);
    assert!(core::mem::align_of::<Twist>() == 8);
};

Dart 示例

import 'dart:typed_data';

final class TwistView {
  static const int byteLength = 48;

  final ByteData data;

  TwistView(ByteBuffer buffer, [int offsetInBytes = 0])
      : data = ByteData.view(buffer, offsetInBytes, byteLength);

  double get linearX => data.getFloat64(0, Endian.little);
  set linearX(double value) => data.setFloat64(0, value, Endian.little);

  double get linearY => data.getFloat64(8, Endian.little);
  set linearY(double value) => data.setFloat64(8, value, Endian.little);

  double get linearZ => data.getFloat64(16, Endian.little);
  set linearZ(double value) => data.setFloat64(16, value, Endian.little);

  double get angularX => data.getFloat64(24, Endian.little);
  set angularX(double value) => data.setFloat64(24, value, Endian.little);

  double get angularY => data.getFloat64(32, Endian.little);
  set angularY(double value) => data.setFloat64(32, value, Endian.little);

  double get angularZ => data.getFloat64(40, Endian.little);
  set angularZ(double value) => data.setFloat64(40, value, Endian.little);
}

Java 示例

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.DoubleBuffer;

public final class TwistView {
  public static final int BYTE_LENGTH = Double.BYTES * 6;

  private final DoubleBuffer values;

  public TwistView(ByteBuffer buffer, int offset) {
    if (offset < 0 || offset + BYTE_LENGTH > buffer.capacity()) {
      throw new IndexOutOfBoundsException("Twist payload requires 48 bytes");
    }
    this.values = buffer.order(ByteOrder.LITTLE_ENDIAN)
        .slice(offset, BYTE_LENGTH)
        .asDoubleBuffer();
  }

  public double linearX() { return values.get(0); }
  public void linearX(double value) { values.put(0, value); }

  public double linearY() { return values.get(1); }
  public void linearY(double value) { values.put(1, value); }

  public double linearZ() { return values.get(2); }
  public void linearZ(double value) { values.put(2, value); }

  public double angularX() { return values.get(3); }
  public void angularX(double value) { values.put(3, value); }

  public double angularY() { return values.get(4); }
  public void angularY(double value) { values.put(4, value); }

  public double angularZ() { return values.get(5); }
  public void angularZ(double value) { values.put(5, value); }
}