private void initField() {
		width = MainWindow.getInstance().getWidth();
		height = MainWindow.getInstance().getHeight();
		int maxX = 0;
		int maxY = 0;

		switch (currentModus) {
		case MODUS_3x3:
			maxX = 3;
			maxY = 3;
			break;
		case MODUS_4x3:
			maxX = 4;
			maxY = 3;
			break;
		case MODUS_5x4:
			maxX = 5;
			maxY = 4;
			break;
		}

		int maxRadius_x = width / (maxX + 2) / 2;
		int maxRadius_y = height / (maxY + 1) / 2;

		int radius = Math.min(maxRadius_x, maxRadius_y);

		circles.clear();
		for (int dx = 0; dx < maxX; dx++) {
			for (int dy = 0; dy < maxY; dy++) {
				double x = (dx * width + 0.5 * width) / maxX;
				double y = (dy * height + 0.5 * height) / maxY;

				circles.add(new HitCircle((int) x, (int) y, radius));
			}
		}
	}