如何在 Surface 视图中的图像上实现洪水填充算法？我已经在 Activity 中成功使用了这个算法。//这是我的课程，我尝试在图像的特定区域填充颜色 public class DrawCanvas extends SurfaceView implements Callback {
Bean bean;
Draw d;
String tag;
private Paint paint;
private Path path;
Bitmap mBitmap;
ProgressDialog pd;
final Point p1 = new Point();
Canvas canvas;
private static final float TOUCH_TOLERANCE = 4;
float mX,mY;
public DrawCanvas(Context context)
{
super(context);
}
public DrawCanvas(Context context, AttributeSet attrs)
{
super(context, attrs);
this.paint = new Paint();
this.paint.setAntiAlias(true);
pd= new ProgressDialog(context);
this.paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(5f);
this.path = new Path();
getHolder().addCallback(this);
setFocusable(true);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
{
}
@Override
public void surfaceCreated(SurfaceHolder holder)
{
try
{
canvas = holder.lockCanvas(null);
synchronized (holder)
{
onDraw(canvas);
}
}
catch (Exception e)
{
e.printStackTrace();
} finally
{
if (canvas != null)
{
holder.unlockCanvasAndPost(canvas);
}
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder)
{
}
@Override
public void onDraw(Canvas canvas)
{
//super.onDraw(canvas);
this.canvas=canvas;
mBitmap = BitmapFactory.decodeResource(getResources(),R.drawable.c);
this.paint.setColor(Color.GREEN);
canvas.drawBitmap(mBitmap, 0, 0,paint);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{ System.out.println("touch");
float x = event.getX();
float y = event.getY();
switch(event.getAction())
{
case MotionEvent.ACTION_DOWN:
//final Point p1 = new Point();
p1.x=(int) x;
p1.y=(int) y;
final int sourceColor= mBitmap.getPixel((int)x,(int) y);
final int targetColor = paint.getColor();
new TheTask(mBitmap, p1, sourceColor, targetColor).execute();
invalidate();
}
return true;
}
public void clear() {
path.reset();
invalidate();
}
public int getCurrentPaintColor()
{
return paint.getColor();
}
class TheTask extends AsyncTask<Void, Integer, Void> {
Bitmap bmp;
Point pt;
int replacementColor,targetColor;
public TheTask(Bitmap bm,Point p, int sc, int tc)
{
this.bmp=bm;
this.pt=p;
this.replacementColor=tc;
this.targetColor=sc;
pd.setMessage("Filling....");
pd.show();
}
protected void onPreExecute() {
pd.show();
}
protected void onProgressUpdate(Integer... values) {
}
protected Void doInBackground(Void... params)
{
System.out.println("in flood fill");
FloodFill f= new FloodFill();
f.floodFill(bmp,pt,targetColor,replacementColor);
return null;
}
protected void onPostExecute(Void result) {
pd.dismiss();
invalidate();
}
}
public class FloodFill
{
public void floodFill(Bitmap image, Point node, int targetColor,int replacementColor)
{ System.out.println("in class floodfill");
int width = image.getWidth();
int height = image.getHeight();
int target = targetColor;
int replacement = replacementColor;
System.out.println("target color"+targetColor+"replacement"+replacementColor);
if (target != replacement) {
Queue<Point> queue = new LinkedList<Point>();
do {
int x = node.x;
int y = node.y;
while (x > 0 && image.getPixel(x - 1, y) == target) {
x--;
}
boolean spanUp = false;
boolean spanDown = false;
while (x < width && image.getPixel(x, y) == target) {
image.setPixel(x, y, replacement);
if (!spanUp && y > 0
&& image.getPixel(x, y - 1) == target) {
queue.add(new Point(x, y - 1));
spanUp = true;
} else if (spanUp && y > 0
&& image.getPixel(x, y - 1) != target) {
spanUp = false;
}
if (!spanDown && y < height - 1
&& image.getPixel(x, y + 1) == target) {
queue.add(new Point(x, y + 1));
spanDown = true;
} else if (spanDown && y < height - 1
&& image.getPixel(x, y + 1) != target) {
spanDown = false;
}
x++;
}
} while ((node = queue.poll()) != null);
}
}
}
}