用于翻转（镜面反射）MovieClip 的错误矩阵

Question

我目前正在使用 AS3 开发一个不错的小型 2D 游戏引擎。您甚至可以通过 XML 加载不同的 Flash 影片剪辑以实现不同的动画。其中一项功能还允许您在执行特定操作时翻转动画。这样你就可以有 1 个左右动画（像往常一样）。我的矩阵变换工作正常；然而，我认为我来回翻转事情的逻辑是不正确的。结果是在错误的时间播放错误的动画。我决定根据移动物体的速度而不是按键来播放动画，因为我涉及到物理元素。

以下是游戏当前状态的链接：http://parrisstudios.com/Game_Design/gameEngineDemo/< /a>

问题主要是动画在不正确的时间播放，或者在应该播放的时候没有播放。

这是我的翻转代码（让我知道你们的想法）： ps：方向变量是角色最后面对的方向（本例中为左或右，稍后在代码中描述）

private function drawJumpMode():void {
        var change:Boolean = false;
        //decide whether to swap graphics or continue playing

        if (Math.abs(particleGroup.particles[0].velocity.y) < epsilon && Math.abs(particleGroup.particles[0].velocity.x) < epsilon && direction == "right") {
            if (lastClipAction != "stillRight"){ 
                lastClipAction = "stillRight";
                change = true;
            }
        }
        else if (Math.abs(particleGroup.particles[0].velocity.y) < epsilon && Math.abs(particleGroup.particles[0].velocity.x) < epsilon && direction == "left") {
            if (lastClipAction != "stillLeft"){ 
                lastClipAction = "stillLeft";
                change = true;
            }
        }
        else if (particleGroup.particles[0].velocity.y > 0 && Math.abs(particleGroup.particles[0].velocity.x) < epsilon) {
            if (lastClipAction != "down"){ 
                lastClipAction = "down";
                change = true;
            }
        }
        else if (particleGroup.particles[0].velocity.y < 0 && Math.abs(particleGroup.particles[0].velocity.x) < epsilon) {
            if (lastClipAction != "up"){ 
                lastClipAction = "up";
                change = true;
            }
        }
        else if (particleGroup.particles[0].velocity.x > 0) {
            if (lastClipAction != "right") {
                lastClipAction = "right";
                direction = "right";
                change = true;              
            }
        }
        else if (particleGroup.particles[0].velocity.x < 0) {
            if (lastClipAction != "left"){ 
                lastClipAction = "left";
                direction = "left";
                change = true;
            }
        }

        //If the movie clip has changed, swap the old one back into the all clips library and get the new one.
        if (change) {
            //set flip to false whenever there is a change in movie clip
            flipped = false;
            //if the movie clip was flipped before, this should flip it
                            //back to normal
            flip();
                            //remove movie clip from the scene
            game.removeChild(playingMovieClip);
                            //check it back into the movie clip library
            allClips.addChild(playingMovieClip);
                            //add the movie clip into the scene
            playingMovieClip = MovieClip(allClips.getChildByName(actionToClip[lastClipAction + "Name"]));
            game.addChild(playingMovieClip);
        }

        //Flip if needed
        flip();

        //set it to true so that it won't be constantly flipped.
        flipped = true;

        //set movie clip to be center over the main particle
        playingMovieClip.x = particleGroup.particles[0].center.x;
        playingMovieClip.y = particleGroup.particles[0].center.y;
    }
private function flip():void {
        //If a transformation is required, then do so
        if (actionToClip[lastClipAction + "H"]=="1" && !flipped){
            flipHorizontal(playingMovieClip);
        }
        if (actionToClip[lastClipAction + "V"]=="1" && !flipped){
            flipVertical(playingMovieClip);
        }
    }

Answer 1

我相信有问题的代码就在这里。

            //If the movie clip has changed, swap the old one back into the all clips library and get the new one.
            if (change) {
                    //set flip to false whenever there is a change in movie clip
                    flipped = false;
                    //if the movie clip was flipped before, this should flip it
                        //back to normal
                    flip();
                        //remove movie clip from the scene
                    game.removeChild(playingMovieClip);
                        //check it back into the movie clip library
                    allClips.addChild(playingMovieClip);
                        //add the movie clip into the scene
                    playingMovieClip = MovieClip(allClips.getChildByName(actionToClip[lastClipAction + "Name"]));
                    game.addChild(playingMovieClip);
            }

            //Flip if needed
            flip();

问题是你在这里做了两次翻转。如果您实际上正在更改更改中的剪辑，则此功能可以找到。例如，如果您从右侧跑步变为右侧站立。当你从右跑转到左跑时就会出错。由于它们是刚刚翻转的同一个剪辑，因此在这种情况下您最终会翻转两次。这会导致月球漫步行为:-)。

我建议清理这个逻辑并提供一种重置翻转的方法。不要翻转回原始方向，而是重置回原来的方向，这样您就可以保证剪辑的状态。