Java2D why when scrolling moves the cursor relative to the grid node?

Good day, trying to draw a grid and bind the cursor to the nodes of this grid. Inherited a class from JPanel, drew a grid on it, processed a mouse, asked the whole case a large size and put it in the JScrollPane for scrolling. And everything seems to be normal, but I noticed that if you move the scrollbar to the right, that is, to move the panel inside the window, then the cursor (my painted cross) stops to stand exactly in the grid nodes. If you move the scrollbars to the zero position (that is, the horizontal one is completely to the left, and the vertical one is fully upward viewport.x = 0 and viewport.y = 0) then everything works fine. Initially, I sinned not taking into account the viewport position, but it seems to be no, I translate the coordinates from window to world and back again in a timely manner, and subtracting the viewport position does not give anything. Tell me, what could be the error, but already broke his head?

 public class DrawArea extends JPanel implements MouseListener, 
                                                 MouseMotionListener, 
                                                 MouseWheelListener { 


private int aDPI = 300; /** По умолчанию панель будет размером с лист А4 */ private Dimension aSize = TR_Utils.mmsToPixels(TR_Utils.A4_PAGE_SIZE_MM, aDPI); private Dimension operateAreaSize = new Dimension(aSize); /** Коэффициент зумирования */ private double scaleFactor = 5.0; /** Размер сетки(в пикселах), если включена */ private int aGridSize = TR_Utils.mmsToPixels(0.01, aDPI); private int operateGridSize = aGridSize; /** Позиция курсора - позиция от которой рисуем(в логических, мировых координатах) */ private Point crossHairPosition = new Point(0, 0); /** Привязывать ли курсор к сетке */ private boolean snapCursorToGrid = true; /** Включаем выключаем сетку */ private boolean isGridEnabled = true; /** Крест по центру экрана, если надо */ private boolean isCrossEnabled = true; /** Сглаживание, если требуется */ private boolean isAnlialiasingEnabled = false; /** Включен режим рисования(рисуется курсор для * рисования на панели, иначе простой указатель) */ private boolean isDrawMode = true; private boolean isShowCrossHair = isDrawMode; /** Включен ли режим просмотра для панели. * В этом режиме запрещено редактировать или что-либо рисовать на панели, * события мыши и клавиатуры игнорируются, изображение на панели * панорамируется(если необходимо) */ private boolean isViewMode = false; /** Координата, на которой нажали кнопку */ private Point mousePressedPos; //GridSize s = new GridSize(15, SizeMeasureUnits.MIL); private AffineTransform at = new AffineTransform(); public DrawArea() { setPreferredSize(operateAreaSize); System.out.println("Size w: " + aSize.width + " h: " + aSize.height); addMouseMotionListener(this); addMouseListener(this); addMouseWheelListener(this); validate(); } @Override public Dimension getPreferredSize() { return new Dimension(operateAreaSize); } public void setCenterInViewport() { Container parent = getParent(); if (parent instanceof JViewport) { JViewport port = (JViewport)parent; Rectangle viewRect = port.getViewRect(); int width = getWidth(); int height = getHeight(); viewRect.x = (width - viewRect.width) / 2 - viewRect.x; viewRect.y = (height - viewRect.height) / 2 - viewRect.y; port.scrollRectToVisible(viewRect); } } /** Находит ближайший узел сетки для установки курсора. * curX, curY - координаты курсора в мировых координатах */ private Point getNearestGridPosition(int curX, int curY) { int cellx = (int)Math.round(curX / operateGridSize); int celly = (int)Math.round(curY / operateGridSize); int x = cellx * operateGridSize; int y = celly * operateGridSize; System.out.println("Grid size: " + aGridSize + " ScaleFactor: " + scaleFactor + " operateGridSize: " + operateGridSize); System.out.println("Cursor pos - x: " + curX + " y: " + curY); System.out.println("Cell num - x: " + cellx + " y: " + celly); System.out.println("CrossHairPos - x: " + x + " y: " + y); System.out.println("----------------------------------------"); return new Point(x, y); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g; setBackground(Color.WHITE); /* Prepare draw area */ if(isGridEnabled) { int w = getWidth(); int h = getHeight(); // int gridStep = (int)(gridSize * Math.round(scaleFactor)); // int gridStep = (int) Math.floor(gridSize * scaleFactor); g2d.setColor(new Color(235, 235, 235)); System.out.print("X draw values:"); for(int i = operateGridSize; i < w; i += operateGridSize) { g2d.drawLine(i, 0, i, h); if( i <= w/7) System.out.print(" " + i); } System.out.println(""); for(int j = operateGridSize; j < h; j += operateGridSize) g2d.drawLine(0, j , w, j); } if (isShowCrossHair) { int cs = 12; // размер крестика-курсора в пикселях g2d.setColor(Color.GRAY); /* Координаты курсора в мировых координатах, приведем их к оконным */ int cx = (int)crossHairPosition.getX(); int cy = (int)crossHairPosition.getY(); Point p = SwingUtilities.convertPoint(this, new Point(cx, cy), getParent()); g2d.drawLine(px-cs/2, py, p.x+cs/2, py); g2d.drawLine(px, py-cs/2, px, p.y+cs/2); } g2d.dispose(); } /****** MOUSE EVENTS ******/ @Override public void mouseClicked(MouseEvent me) {} @Override public void mousePressed(MouseEvent me) { mousePressedPos = me.getPoint(); System.out.println("mousePressedPos " + mousePressedPos.x + "/" + mousePressedPos.y); if(SwingUtilities.isMiddleMouseButton(me)) { setCursor(new Cursor(Cursor.MOVE_CURSOR)); isShowCrossHair = false; repaint(); } } @Override public void mouseReleased(MouseEvent me) { setCursor(new Cursor(Cursor.DEFAULT_CURSOR)); isShowCrossHair = true; repaint(); } @Override public void mouseEntered(MouseEvent me) {} @Override public void mouseExited(MouseEvent me) {} @Override public void mouseDragged(MouseEvent me) { if(!isViewMode) { if(SwingUtilities.isMiddleMouseButton(me)) { if(mousePressedPos != null) { JViewport port = (JViewport)getParent(); Rectangle viewRect = port.getViewRect(); int deltaX = mousePressedPos.x - me.getX(); int deltaY = mousePressedPos.y - me.getY(); viewRect.x += deltaX; viewRect.y += deltaY; scrollRectToVisible(viewRect); } } } } @Override public void mouseMoved(MouseEvent me) { if(!isViewMode) { int x = me.getX(); int y = me.getY(); // в мировые координаты Point p = SwingUtilities.convertPoint(getParent(), new Point(x, y), this); JViewport port = (JViewport)getParent(); Point vp = port.getViewPosition(); System.out.println( "cur_wnd.x: " + x + " cur_wnd.y: " + y + " / cur_world.x: " + px + " cur_world.y: " + py + " / viewpos.x: " + vp.x + " viewpos.y: " + vp.y); if(snapCursorToGrid) { // Привязываем курсор к узлам сетки Point np = getNearestGridPosition(px, py); crossHairPosition.setLocation(np.x, np.y); } else { crossHairPosition.setLocation(px, py); } repaint(); } } @Override public void mouseWheelMoved(MouseWheelEvent mwe) { if(!isViewMode) { /* минус для изменения направления движения колесика при маштабировании, так удобнее */ scaleFactor += -(0.05 * mwe.getWheelRotation()); scaleFactor = Math.max(0.05, scaleFactor); scaleFactor = Math.min(scaleFactor, 10); // пересчитываем размер области рисования operateAreaSize.setSize((int)(aSize.width * scaleFactor), (int)(aSize.height * scaleFactor)); System.out.println("scaleFactor: " + scaleFactor); // пересчитываем размер сетки operateGridSize = (int)Math.round(aGridSize * scaleFactor); System.out.println("operateGridSize(px): " + operateGridSize); validate(); repaint(); } } 

}