示例#1
0
 /** 计算两点间距离,结果取数的级别 */
 private static float calculateDistance(PointBean start, PointBean end) {
   float result = 1;
   float x = Math.abs(start.getX() - end.getX());
   float y = Math.abs(start.getY() - end.getY());
   String dis = (int) Math.sqrt(x * x + y * y) + "";
   int level = dis.trim().length();
   for (int i = 1; i < level; ++i) {
     result *= 10;
   }
   return result;
 }
示例#2
0
  /** 用两个点算他们的中点,完成一次贝塞尔曲线计算 */
  private static void addMidPoint() {
    PointBean one = mScreenPoints.get(0);
    PointBean three = mScreenPoints.get(1);
    PointBean mid =
        new PointBean(((one.getX() + three.getX()) / 2), (one.getY() + three.getY()) / 2);

    if (mBezierPoints.size() == 2) { // 前面已经完成一次中点计算了
      mBezierPoints.add(mid);
      calculateBezier();
      mBezierPoints.clear(); // 计算完之后,要将这一次的中点和屏幕点记下来,给下一个中点完成贝塞尔曲线
      mBezierPoints.add(mid);
      mBezierPoints.add(three);
    } else { // 第一次完成中点计算
      mBezierPoints.add(one); // 第一个点,以线性的贝塞尔曲线连接
      mBezierPoints.add(mid);
      mBezierPoints.add(three);
      calculateBezier();
      releasePoints();
      // 添加点,等下一次用
      mBezierPoints.add(mid);
      mBezierPoints.add(three);
    }
  }
示例#3
0
  /** 计算贝塞尔曲线点 */
  private static void calculateBezier() {
    PointBean mControlPoint; // 贝塞尔控制点
    PointBean mBezierPoint; // 贝塞尔曲线上的点
    PointBean mStartPoint; // 贝塞尔曲线起点
    PointBean mEndPoint; // 贝塞尔曲线终点
    float t = 0.01f; // 默认t取0.01
    float BezierX;
    float BezierY;
    mControlPoint = mBezierPoints.get(1);
    mStartPoint = mBezierPoints.get(0);
    mEndPoint = mBezierPoints.get(2);

    mBezierResult.add(mStartPoint);

    // 先计算两点之间距离,根据距离选择t
    float distance; // 起点和终点两点间距离
    distance = calculateDistance(mStartPoint, mEndPoint);
    t = 1 / distance; // 再根据距离选取t的取值 100->0.01,   10->0.1,   1->1
    float step = t / 2; // 除以2再取多一点的点

    if (t > 0 && t < 1) { // t取值范围
      // 公式 (1-t)^2 * x1 + 2 * t * (1-t) * x0 + t^2 * x2 = x
      for (; t <= 1.0f; t += step) {
        BezierX =
            (float) Math.pow(1 - t, 2) * mBezierPoints.get(0).getX()
                + 2 * t * (1 - t) * mControlPoint.getX()
                + (float) Math.pow(t, 2) * mBezierPoints.get(2).getX();

        BezierY =
            (float) Math.pow(1 - t, 2) * mBezierPoints.get(0).getY()
                + 2 * t * (1 - t) * mControlPoint.getY()
                + (float) Math.pow(t, 2) * mBezierPoints.get(2).getY();

        mBezierPoint = new PointBean(BezierX, BezierY);
        mBezierResult.add(mBezierPoint);
      }
    }

    mBezierResult.add(mEndPoint);

    switch (Constant.CURRENT_USE_TYPE) {
      case Constant.PAINT:
        ObjectUtil.createBezierLine(mBezierResult);
        break;
      case Constant.FIREWORKS:
        // 需要每个点位置刚好接上,不能重叠
        mDeleteLeftPoints = splicePoints(mBezierResult);
        ObjectUtil.createBezierLine(mDeleteLeftPoints);
        break;
      case Constant.WALLPAPER:
        // 需要先除去一些点
        mDeleteLeftPoints = deletePoints(mBezierResult);
        ObjectUtil.createBezierLine(mDeleteLeftPoints);
        break;
      case Constant.MOSAIC:
        ObjectUtil.createBezierLine(mBezierResult);
        break;
      case Constant.ERASER:
        ObjectUtil.createBezierLine(mBezierResult);
        break;
      default:
        break;
    }
  }
示例#4
0
 /**
  * 也是计算两点间距离,但是这个是结果准确的
  *
  * @param start
  * @param end
  * @return
  */
 private static float calculateExactDistance(PointBean start, PointBean end) {
   float x = Math.abs(start.getX() - end.getX());
   float y = Math.abs(start.getY() - end.getY());
   return (float) Math.sqrt((x * x + y * y));
 }