How to find how many pixel long a line is

Question

I am drawing lines using drawLine method in Java. I know beginning and end points of lines.

1. How can I measure the length of lines as pixels?
2. If I am working on a BufferedImage whose width and height are determined by Dimension(500,500), do the points which determine the start and the end of a line correspond to the pixels? Then will calculating only the distance of two points be sufficient for measuring the pixel length of line?

Answer 1

BufferedImage以整数形式工作;笛卡尔空间。所以每个像素对应一个点。

如果您有积分，请使用distance formula确定长度。

int distance = (int) Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));

如果您使用Point2D课程作为积分，有多种方法可以让您更轻松地确定距离。

• double distance(double px, double py)
  • 返回此Point2D到指定点的距离。
• static double distance(double x1, double y1, double x2, double y2)
  • 返回两点之间的距离。
• double distance(Point2D pt)
  • 返回从此Point2D到指定Point2D的距离。
• double distanceSq(double px, double py)
  • 返回从此Point2D到指定点的距离的平方。
• static double distanceSq(double x1, double y1, double x2, double y2)
  • 返回两点之间距离的平方。
• double distanceSq(Point2D pt)
  • 返回从此Point2D到指定Point2D的距离的平方。