转换点从坐标系屏幕到x y

Question

将点从坐标系转换为java，

in Java Frame
+ - *|||y

我想要这个

y||+ - - - x

请帮帮我

Answer 1

你可以改变它，让y = Ymax - y

  public void paintControl(PaintEvent e) {
        Canvas canvas = (Canvas) e.widget;
        int maxX = canvas.getSize().x - 20;
        int maxY = canvas.getSize().y - 20;
        e.gc.setForeground(e.display.getSystemColor(SWT.COLOR_BLUE));
        int h = 0;
        int pixelCount = 4;
        e.gc.drawLine(50, maxY, maxX, maxY);
        e.gc.drawLine(50, maxY, 50, 0 + 20);