我正在制作类似油漆的应用，但我遇到了麻烦。
我知道我已经重新绘制了每个帧的所有对象，但这反过来会使许多对象可见时性能进一步降低。
我还注意到只清除了一次背景，然后在绘画处于活动状态时添加要绘制到表面的对象，使得屏幕几乎闪烁到引发癫痫的程度。
那么无论绘制多少个物体，使绘画应用程序100％平滑的最佳方法是什么？
癫痫诱导代码：
public void run()
{
while (running)
{
if (!holder.getSurface().isValid())
continue;
if (drawObjectsToAdd.size() == 0)
continue;
drawing = true;
Canvas c = holder.lockCanvas();
if (redrawBackground)
{
c.drawARGB(255, 255, 255, 255);
redrawBackground = false;
}
drawObjects.addAll(drawObjectsToAdd);
drawObjectsToAdd.clear();
for (DrawObject draw : drawObjects)
{
draw.Draw(c, paint);
}
holder.unlockCanvasAndPost(c);
drawing = false;
}
}
这会在线程外部添加一个新对象，但它会让屏幕闪烁太多让我感到头疼 - 而且我只重绘了一次背景。
起初平滑但过了一段时间变得迟钝，可能是因为最后必须添加数百个数百个对象：
public void run()
{
while (running)
{
if (!holder.getSurface().isValid())
continue;
if (drawObjectsToAdd.size() > 0)
{
drawObjects.addAll(drawObjectsToAdd);
drawObjectsToAdd.clear();
redraw = true;
}
if (clear)
{
drawObjectsToAdd.clear();
drawObjects.clear();
redraw = true;
clear = false;
}
if (!redraw)
continue;
drawing = true;
Canvas c = holder.lockCanvas();
c.drawARGB(255, 255, 255, 255);
for (DrawObject draw : drawObjects)
{
try
{
draw.Draw(c, paint);
}
catch (Exception ex) { }
}
holder.unlockCanvasAndPost(c);
drawing = false;
redraw = false;
}
}
我，至少对于这个应用程序想要存储所有添加的对象，所以只要它一直平滑，它并不重要。最好添加一个圆圈 - 它会在表面上渲染一个新的位图，而不是每帧重绘大量的对象 - 而是存储它们但不添加已绘制的对象。
更新
我想要的伪代码：
If no background is drawn
Draw background color
If new items have been added
Draw only new items to the background
Store new items in objects list
这样，我们只会绘制一次背景。添加新项目时，仅将该项目绘制到现有曲面。当对象增加时，遍历每个项目将大大降低性能，并且使用起来不会令人愉快。
更新2：
private void Draw()
{
while (running)
{
if (!holder.getSurface().isValid())
continue;
if (picture == null)
{
picture = new Picture();
Canvas c = picture.beginRecording(getWidth(), getHeight());
c.drawARGB(255, 255, 255, 255);
picture.endRecording();
}
if (drawObjectsToAdd.size() > 0)
{
drawObjects.addAll(drawObjectsToAdd);
drawObjectsToAdd.clear();
Canvas c = picture.beginRecording(getWidth(), getHeight());
for (DrawObject draw : drawObjects)
{
draw.Draw(c, paint);
}
picture.endRecording();
drawObjects.clear();
}
Canvas c2 = holder.lockCanvas();
c2.drawPicture(picture);
holder.unlockCanvasAndPost(c2);
}
}
Update 2 中的最后一个方法会让它呈现所有的行，例如＆＃34; Snake游戏＆＃34;添加圈子时。看起来像一条动人的蛇在背景上，其中一些圆圈消失了一帧而其他人不在下一个。如果我跳过重绘每一帧，它将改变这些可见的圆圈中的哪一个。
答案 0 :(得分：1)
那个Picture实现怎么样？将MAX_DRAWERS增加到一个合理的值，看看它是如何工作的
class SV extends SurfaceView implements SurfaceHolder.Callback, Runnable {
private static final int MAX_DRAWERS = 8;
private boolean mRunning = true;
private List<Picture> mPictures = new LinkedList<Picture>();
private List<Drawer> mDrawers = new LinkedList<Drawer>();
private Paint mPaint;
public SV(Context context) {
super(context);
mPaint = new Paint();
mPaint.setColor(0xffffff00);
getHolder().addCallback(this);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
new Thread(this).start();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public synchronized void surfaceDestroyed(SurfaceHolder holder) {
mRunning = false;
notify();
}
@Override
public synchronized boolean onTouchEvent(MotionEvent event) {
Drawer drawer = new Drawer(event.getX(), event.getY());
mDrawers.add(drawer);
if (mDrawers.size() > MAX_DRAWERS) {
Picture picture = new Picture();
Canvas canvas = picture.beginRecording(getWidth(), getHeight());
mPaint.setAlpha(0xbb);
for (Drawer dr : mDrawers) {
dr.draw(canvas, mPaint);
}
picture.endRecording();
mPaint.setAlpha(0xff);
mPictures.add(picture);
mDrawers.clear();
Log.d(TAG, "onTouchEvent new Picture");
}
notify();
return false;
}
@Override
public synchronized void run() {
SurfaceHolder holder = getHolder();
while (mRunning) {
// Log.d(TAG, "run wait...");
try {
wait();
} catch (InterruptedException e) {
}
if (mRunning) {
// Log.d(TAG, "run woke up");
Canvas canvas = holder.lockCanvas();
canvas.drawColor(0xff0000ff);
for (Picture picture : mPictures) {
picture.draw(canvas);
}
for (Drawer drawer : mDrawers) {
drawer.draw(canvas, mPaint);
}
holder.unlockCanvasAndPost(canvas);
}
}
Log.d(TAG, "run bye bye");
}
class Drawer {
private float x;
private float y;
public Drawer(float x, float y) {
this.x = x;
this.y = y;
}
public void draw(Canvas canvas, Paint paint) {
canvas.drawCircle(x, y, 8, paint);
}
}
}
答案 1 :(得分：0)
您可以在每个帧中生成对象列表，只是在绘制后将其丢弃。为什么？生成一次绘制对象列表，然后绘制它们。
你的绘图线程所需的一切......
public void run() {
while (running)
{
Canvas c = holder.lockCanvas();
c.drawARGB(255, 255, 255, 255);
for (DrawObject draw : drawObjects)
{
try
{
draw.Draw(c, paint);
}
catch (Exception ex) { }
}
holder.unlockCanvasAndPost(c);
}
}