如何在 Java libGDX 中为我的游戏正确添加足迹

Question

I am trying to add footprints to my game so when the player walks over snow or sand etc it produces little footprints which fade out. This code below almost works. What happens is that it constantly makes new footprints when the player walks so I get a long row of an indistinguishable mesh of footprints which update with each gamecycle.

What I believe I need is a delay between new footprints but I am not sure how to properly do that. Does anyone have any suggestions?

if(player.overlaps(snow))
          { 
             if(player.getSpeed() != 0)
             {
             FootPrint footPrint = new  FootPrint(0,0, mainStage);
             hero.toFront();
             footPrint.setPosition(player.getX(), player.getY());
             footPrint.addAction(Actions.fadeOut(5.0f));   
             footPrint.addAction(Actions.after(Actions.removeActor()));
              }
         }

Answer 1

You can add FootprintIntervalCounter instance and call it in your alghorithm. The naive implementation is:

public class FootprintIntervalCounter {

    private long lastRenderTimeMillis;
    private long interval;
    private boolean renderingCompletionFlag;

    public boolean isFootprintNeeded() {
        if (!renderingCompletionFlag) {
            return false;
        }
        long currentTime = System.currentTimeMillis();
        boolean isNeeded = (currentTime - lastRenderTimeMillis) > interval;
        if (isNeeded) {
            renderingCompletionFlag = false;
        }
        return renderingCompletionFlag;
    }
    
    public void afterFootprintIsRendered(long renderTimeMillis) {
        renderingCompletionFlag = true;
        lastRenderTimeMillis = renderTimeMillis;
    }
}