我正在尝试使用Fill Flood算法为应用制作多维数据集绘画工具。
这是算法的代码：
public class QueueLinearFloodFiller {
protected Bitmap image = null;
protected int[] tolerance = new int[] { 0, 0, 0 };
protected int width = 0;
protected int height = 0;
protected int[] pixels = null;
protected int fillColor = 0;
protected int[] startColor = new int[] { 0, 0, 0 };
protected boolean[] pixelsChecked;
protected Queue<FloodFillRange> ranges;
// Construct using an image and a copy will be made to fill into,
// Construct with BufferedImage and flood fill will write directly to
// provided BufferedImage
public QueueLinearFloodFiller(Bitmap img) {
copyImage(img);
}
public QueueLinearFloodFiller(Bitmap img, int targetColor, int newColor) {
useImage(img);
setFillColor(newColor);
setTargetColor(targetColor);
}
public void setTargetColor(int targetColor) {
startColor[0] = Color.red(targetColor);
startColor[1] = Color.green(targetColor);
startColor[2] = Color.blue(targetColor);
}
public int getFillColor() {
return fillColor;
}
public void setFillColor(int value) {
fillColor = value;
}
public int[] getTolerance() {
return tolerance;
}
public void setTolerance(int[] value) {
tolerance = value;
}
public void setTolerance(int value) {
tolerance = new int[] { value, value, value };
}
public Bitmap getImage() {
return image;
}
public void copyImage(Bitmap img) {
// Copy data from provided Image to a BufferedImage to write flood fill
// to, use getImage to retrieve
// cache data in member variables to decrease overhead of property calls
width = img.getWidth();
height = img.getHeight();
image = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(image);
canvas.drawBitmap(img, 0, 0, null);
pixels = new int[width * height];
image.getPixels(pixels, 0, width, 1, 1, width - 1, height - 1);
}
public void useImage(Bitmap img) {
// Use a pre-existing provided BufferedImage and write directly to it
// cache data in member variables to decrease overhead of property calls
width = img.getWidth();
height = img.getHeight();
image = img;
pixels = new int[width * height];
image.getPixels(pixels, 0, width, 1, 1, width - 1, height - 1);
}
protected void prepare() {
// Called before starting flood-fill
pixelsChecked = new boolean[pixels.length];
ranges = new LinkedList<>();
}
// Fills the specified point on the bitmap with the currently selected fill
// color.
// int x, int y: The starting coords for the fill
public void floodFill(int x, int y) {
// Setup
prepare();
if (startColor[0] == 0) {
// ***Get starting color.
int startPixel = pixels[(width * y) + x];
startColor[0] = (startPixel >> 16) & 0xff;
startColor[1] = (startPixel >> 8) & 0xff;
startColor[2] = startPixel & 0xff;
}
// ***Do first call to floodfill.
LinearFill(x, y);
// ***Call floodfill routine while floodfill ranges still exist on the
// queue
FloodFillRange range;
while (ranges.size() > 0) {
// **Get Next Range Off the Queue
range = ranges.remove();
// **Check Above and Below Each Pixel in the Floodfill Range
int downPxIdx = (width * (range.Y + 1)) + range.startX;
int upPxIdx = (width * (range.Y - 1)) + range.startX;
int upY = range.Y - 1;// so we can pass the y coord by ref
int downY = range.Y + 1;
for (int i = range.startX; i <= range.endX; i++) {
// *Start Fill Upwards
// if we're not above the top of the bitmap and the pixel above
// this one is within the color tolerance
if (range.Y > 0 && (!pixelsChecked[upPxIdx])
&& CheckPixel(upPxIdx))
LinearFill(i, upY);
// *Start Fill Downwards
// if we're not below the bottom of the bitmap and the pixel
// below this one is within the color tolerance
if (range.Y < (height - 1) && (!pixelsChecked[downPxIdx])
&& CheckPixel(downPxIdx))
LinearFill(i, downY);
downPxIdx++;
upPxIdx++;
}
}
image.setPixels(pixels, 0, width, 1, 1, width - 1, height - 1);
}
// Finds the furthermost left and right boundaries of the fill area
// on a given y coordinate, starting from a given x coordinate, filling as
// it goes.
// Adds the resulting horizontal range to the queue of floodfill ranges,
// to be processed in the main loop.
// int x, int y: The starting coords
protected void LinearFill(int x, int y) {
// ***Find Left Edge of Color Area
int lFillLoc = x; // the location to check/fill on the left
int pxIdx = (width * y) + x;
while (true) {
// **fill with the color
pixels[pxIdx] = fillColor;
// **indicate that this pixel has already been checked and filled
pixelsChecked[pxIdx] = true;
// **de-increment
lFillLoc--; // de-increment counter
pxIdx--; // de-increment pixel index
// **exit loop if we're at edge of bitmap or color area
if (lFillLoc < 0 || (pixelsChecked[pxIdx]) || !CheckPixel(pxIdx)) {
break;
}
}
lFillLoc++;
// ***Find Right Edge of Color Area
int rFillLoc = x; // the location to check/fill on the left
pxIdx = (width * y) + x;
while (true) {
// **fill with the color
pixels[pxIdx] = fillColor;
// **indicate that this pixel has already been checked and filled
pixelsChecked[pxIdx] = true;
// **increment
rFillLoc++; // increment counter
pxIdx++; // increment pixel index
// **exit loop if we're at edge of bitmap or color area
if (rFillLoc >= width || pixelsChecked[pxIdx] || !CheckPixel(pxIdx)) {
break;
}
}
rFillLoc--;
// add range to queue
FloodFillRange r = new FloodFillRange(lFillLoc, rFillLoc, y);
ranges.offer(r);
}
// Sees if a pixel is within the color tolerance range.
protected boolean CheckPixel(int px) {
int red = (pixels[px] >>> 16) & 0xff;
int green = (pixels[px] >>> 8) & 0xff;
int blue = pixels[px] & 0xff;
return (red >= (startColor[0] - tolerance[0])
&& red <= (startColor[0] + tolerance[0])
&& green >= (startColor[1] - tolerance[1])
&& green <= (startColor[1] + tolerance[1])
&& blue >= (startColor[2] - tolerance[2]) && blue <= (startColor[2] + tolerance[2]));
}
// Represents a linear range to be filled and branched from.
protected class FloodFillRange {
public int startX;
public int endX;
public int Y;
public FloodFillRange(int startX, int endX, int y) {
this.startX = startX;
this.endX = endX;
this.Y = y;
}
}
}
这是我在ImageView上处理触摸事件的部分：
filler.setTolerance(150);
imagen.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
int x = (int)motionEvent.getX();
int y = (int)motionEvent.getY();
filler.prepare();
filler.floodFill(x, y);
imagen.setImageBitmap(filler.getImage());
return false;
}
});
问题是坐标不准确。我的意思是，无论我在哪里触摸图像，它都会在其他部分被绘制，而我却没有。
在将事件坐标发送到填充算法之前，是否需要处理它？我也试过一个全屏图像，这种情况一直在发生。
感谢任何帮助！
答案 0 :(得分：2)
你的情况提醒了我this blog post，因为这可能是他在那里修复的同样问题。他必须考虑位图在放入ImageView之前经历的转换。
不是仅在getX()的{{1}}事件中使用getY()和OnTouchListener，而是分别使用getPointerCoords(event)[0]和getPointerCoords(event)[1]创建此方法：
final float[] getPointerCoords(MotionEvent e)
{
final int index = e.getActionIndex();
final float[] coords = new float[] { e.getX(index), e.getY(index) };
Matrix matrix = new Matrix();
getImageMatrix().invert(matrix); //his drawable view extends ImageView
//so it has access to the getImageMatrix.
matrix.postTranslate(getScrollX(), getScrollY());
matrix.mapPoints(coords);
return coords;
}
请注意，如果确实为您提供了解决方案 - 您可以在方法内的getImageMatrix()变量上使用imagen方法，或将矩阵保存到最终变量中并将其用于OnTouchListener。
另请注意，如果这是问题所在 - 您还应该在设置FillFlood时考虑转换以相应地构建维度（这意味着您之前的尝试导致了一个太大/太小的矩阵与原始位图相比）。
一切为了你（使用这个解决方案的一种方式）：
final Matrix transformationMatrix = new Matrix();
imagen.getImageMatrix().invert(transformationMatrix);
transformationMatrix.postTranslate(imagen.getScrollX(), imagen.getScrollY());
imagen.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
float[] transformedCoords = getPointerCoords(event);
int x = (int)transformedCoords[0];
int y = (int)transformedCoords[1];
filler.prepare();
filler.floodFill(x, y);
imagen.setImageBitmap(filler.getImage());
return false;
}
final float[] getPointerCoords(MotionEvent e) {
final int index = e.getActionIndex();
final float[] coords = new float[] { e.getX(index), e.getY(index) };
transformationMatrix.mapPoints(coords);
return coords;
}
});
希望能解决它。