Android

private static final int WIDTH = 20;
    private static final int HEIGHT = 20;
    private static final int COUNT = (WIDTH + 1) * (HEIGHT + 1);
 
    private final Bitmap mBitmap;
    private final float[] mVerts = new float[COUNT * 2];
    private final float[] mOrig = new float[COUNT * 2];
 
    private final Matrix mMatrix = new Matrix();
    private final Matrix mInverse = new Matrix();
    private float[] matrixInverse;
    private int mLastWarpX = -9999; // don't match a touch coordinate
    private int mLastWarpY;
 
    private static void setXY(float[] array, int index, float x, float y) {
        array[(index * 2)] = x;
        array[(index * 2) + 1] = y;
    }
 
    public Warp(Bitmap imgBitmap, float i, float j, Canvas myCanvas) {
        mBitmap = imgBitmap;
        float w = mBitmap.getWidth();
        float h = mBitmap.getHeight();
        // construct our mesh
        int index = 0;
        for (int y = 0; y <= HEIGHT; y++) {
            float fy = h * y / HEIGHT;
            for (int x = 0; x <= WIDTH; x++) {
                float fx = w * x / WIDTH;
                setXY(mVerts, index, fx, fy);
                setXY(mOrig, index, fx, fy);
                index++;
            }
        }
 
        // mMatrix.setTranslate(10, 10);
        mMatrix.invert(mInverse);
 
        float[] pt = {i, j};
        mInverse.mapPoints(pt);
        int x = (int) pt[0];
        int y = (int) pt[1];
        if (mLastWarpX != x || mLastWarpY != y) {
            mLastWarpX = x;
            mLastWarpY = y;
            draw(pt[0], pt[1], myCanvas);
 
        }
 
    }
 
    private void draw(float cx, float cy, Canvas canvas) {
 
        final float K = 10000;
        float[] src = mOrig;
        float[] dst = mVerts;
        for (int i = 0; i < COUNT * 2; i += 2) {
            float x = src[i + 0];
            float y = src[i + 1];
            float dx = cx - x;
            float dy = cy - y;
            float dd = dx * dx + dy * dy;
            float d = dd/2;//(float) Math.sqrt(dd);
            float pull = K / (dd + 0.000001f);
 
            pull /= (d + 0.000001f);
            //   android.util.Log.d("skia", "index " + i + " dist=" + d + " pull=" + pull);

            if (pull >= 1) {
                dst[i + 0] = cx;
                dst[i + 1] = cy;
            } else {
                dst[i + 0] = x + dx * pull;
                dst[i + 1] = y + dy * pull;
            }
        }
 
        canvas.drawColor(0xFFCCCCCC);
        canvas.concat(mMatrix);
        canvas.drawBitmapMesh(mBitmap, WIDTH, HEIGHT, mVerts, 0,
                null, 0, null);
 

    }