finderpattern.java

qrcode的java开源版本

		}
		canvas.println("originPoint is: " + originPoint);
		Point remotePoint = new Point();

		//with origin that the center of Left-Up Finder Pattern, determine other two patterns center.
		//then calculate symbols angle
		if (originPoint.getY() <= remoteLine.getP1().getY() & //1st or 2nd quadant
				originPoint.getY() <= remoteLine.getP2().getY())
			if (remoteLine.getP1().getX() < remoteLine.getP2().getX())
				remotePoint = remoteLine.getP2();
			else
				remotePoint = remoteLine.getP1();
		else if (originPoint.getX() >= remoteLine.getP1().getX() & //2nd or 3rd quadant
				originPoint.getX() >= remoteLine.getP2().getX())
			if (remoteLine.getP1().getY() < remoteLine.getP2().getY())
				remotePoint = remoteLine.getP2();
			else
				remotePoint = remoteLine.getP1();
		else if (originPoint.getY() >= remoteLine.getP1().getY() & //3rd or 4th quadant
				originPoint.getY() >= remoteLine.getP2().getY())
			if (remoteLine.getP1().getX() < remoteLine.getP2().getX())
				remotePoint = remoteLine.getP1();
			else
				remotePoint = remoteLine.getP2();
		else //1st or 4th quadrant
			if (remoteLine.getP1().getY() < remoteLine.getP2().getY())
				remotePoint = remoteLine.getP1();
			else
				remotePoint = remoteLine.getP2();
		
		int r = new Line(originPoint, remotePoint).getLength();
		//canvas.println(Integer.toString(((remotePoint.getX() - originPoint.getX()) << QRCodeImageReader.DECIMAL_POINT)));
		int angle[] = new int[2];
		angle[0] = ((remotePoint.getY() - originPoint.getY()) << QRCodeImageReader.DECIMAL_POINT) / r; //Sin
		angle[1] = ((remotePoint.getX() - originPoint.getX()) << (QRCodeImageReader.DECIMAL_POINT)) / r; //Cos
		
		return angle;
	}
	
	static Point[] getCenter(Line[] crossLines) 
			throws FinderPatternNotFoundException {
		Vector centers = new Vector();
		for (int i = 0; i < crossLines.length - 1; i++) {
			Line compareLine = crossLines[i];
			for (int j = i + 1; j < crossLines.length; j++) {
				Line comparedLine = crossLines[j];
				if (Line.isCross(compareLine, comparedLine)) {
					int x = 0;
					int y = 0;
					if (compareLine.isHorizontal()) {
						x = compareLine.getCenter().getX();
						y = comparedLine.getCenter().getY();		
					}
					else {
						x = comparedLine.getCenter().getX();
						y = compareLine.getCenter().getY();
					}
					centers.addElement(new Point(x,y));
				}
			}
		}
		
		Point[] foundPoints = new Point[centers.size()];
		
		for (int i = 0; i < foundPoints.length; i++) {
			foundPoints[i] = (Point)centers.elementAt(i);
			//System.out.println(foundPoints[i]);
		}
		//System.out.println(foundPoints.length);
		
		if (foundPoints.length == 3) {
			canvas.drawPolygon(foundPoints, Color.RED);	
			return foundPoints;
		}
		else
			throw new FinderPatternNotFoundException("Invalid number of Finder Pattern detected");
	}

	//sort center of finder patterns as Left-Up: points[0], Right-Up: points[1], Left-Down: points[2].
	static Point[] sort(Point[] centers, int[] angle) {

		Point[] sortedCenters = new Point[3];
		
		int quadant = getURQuadant(angle);
		switch (quadant) {
		case 1:
			sortedCenters[1] = getPointAtSide(centers, Point.RIGHT, Point.BOTTOM);
			sortedCenters[2] = getPointAtSide(centers, Point.BOTTOM, Point.LEFT);
			break;
		case 2:
			sortedCenters[1] = getPointAtSide(centers, Point.BOTTOM, Point.LEFT);
			sortedCenters[2] = getPointAtSide(centers, Point.TOP, Point.LEFT);
			break;
		case 3:
			sortedCenters[1] = getPointAtSide(centers, Point.LEFT, Point.TOP);			
			sortedCenters[2] = getPointAtSide(centers, Point.RIGHT, Point.TOP);
			break;
		case 4:
			sortedCenters[1] = getPointAtSide(centers, Point.TOP, Point.RIGHT);
			sortedCenters[2] = getPointAtSide(centers, Point.BOTTOM, Point.RIGHT);
			break;
		}

		//last of centers is Left-Up patterns one
		for (int i = 0; i < centers.length; i++) {
			if (!centers[i].equals(sortedCenters[1]) && 
					!centers[i].equals(sortedCenters[2])) {
				sortedCenters[0] = centers[i];
			}
		}

		return sortedCenters;
	}
	
	static int getURQuadant(int[] angle) {
		int sin = angle[0];
		int cos = angle[1];
		if (sin >= 0 && cos > 0)
			return 1;
		else if (sin > 0 && cos <= 0)
			return 2;
		else if (sin <= 0 && cos < 0)
			return 3;
		else if (sin < 0 && cos >= 0)
			return 4;
		
		return 0;
	}
	
	static Point getPointAtSide(Point[] points, int side1, int side2) {
		Point sidePoint = new Point();
		int x = ((side1 == Point.RIGHT || side2 == Point.RIGHT) ? 0 : Integer.MAX_VALUE);
		int y = ((side1 == Point.BOTTOM || side2 == Point.BOTTOM) ? 0 : Integer.MAX_VALUE);
		sidePoint = new Point(x, y);
			
		for (int i = 0; i < points.length; i++) {
			switch (side1) {
			case Point.RIGHT:
				if (sidePoint.getX() < points[i].getX()) {
					sidePoint = points[i];
				}
				else if (sidePoint.getX() == points[i].getX()) {
					if (side2 == Point.BOTTOM) {
						if (sidePoint.getY() < points[i].getY()) {
							sidePoint = points[i];
						}
					}
					else {
						if (sidePoint.getY() > points[i].getY()) {
							sidePoint = points[i];
						}
					}
				}
				break;
			case Point.BOTTOM:
				if (sidePoint.getY() < points[i].getY()) {
					sidePoint = points[i];
				}
				else if (sidePoint.getY() == points[i].getY()) {
					if (side2 == Point.RIGHT) {
						if (sidePoint.getX() < points[i].getX()) {
							sidePoint = points[i];
						}
					}
					else {
						if (sidePoint.getX() > points[i].getX()) {
							sidePoint = points[i];
						}
					}
				}
				break;
			case Point.LEFT:
				if (sidePoint.getX() > points[i].getX()) {
					sidePoint = points[i];
				}
				else if (sidePoint.getX() == points[i].getX()) {
					if (side2 == Point.BOTTOM) {
						if (sidePoint.getY() < points[i].getY()) {
							sidePoint = points[i];
						}
					}
					else {
						if (sidePoint.getY() > points[i].getY()) {
							sidePoint = points[i];
						}
					}
				}
				break;
			case Point.TOP:
				if (sidePoint.getY() > points[i].getY()) {
					sidePoint = points[i];
				}
				else if (sidePoint.getY() == points[i].getY()) {
					if (side2 == Point.RIGHT) {
						if (sidePoint.getX() < points[i].getX()) {
							sidePoint = points[i];
						}
					}
					else {
						if (sidePoint.getX() > points[i].getX()) {
							sidePoint = points[i];
						}
					}
				}
				break;
			}
		}
		return sidePoint;
	}
	
	static int[] getWidth(boolean[][] image, Point[] centers,  int[] sincos) 
		throws ArrayIndexOutOfBoundsException {

		int[] width = new int[3];
		
		for (int i = 0; i < 3; i++) {
			boolean flag = false;
			int lx, rx;
			int y = centers[i].getY();
			for (lx = centers[i].getX(); lx >= 0; lx--) {
				if (image[lx][y] == QRCodeImageReader.POINT_DARK &&
						image [lx - 1][y] == QRCodeImageReader.POINT_LIGHT) {
					if (flag == false) flag = true;
					else break;
				}
			}
			flag = false;
			for (rx = centers[i].getX(); rx < image.length; rx++) {
				if (image[rx][y] == QRCodeImageReader.POINT_DARK &&
						image[rx + 1][y] == QRCodeImageReader.POINT_LIGHT)  {
					if (flag == false) flag = true;
					else break;
				}
			}
			width[i] = (rx - lx + 1);
		}
		return width;
	}
	
	static int calcRoughVersion(Point[] center, int[] width) {
		final int dp = QRCodeImageReader.DECIMAL_POINT;
		int lengthAdditionalLine = (new Line(center[UL], center[UR]).getLength()) << dp ;
		int avarageWidth = ((width[UL] + width[UR]) << dp) / 14;
		int roughVersion = ((lengthAdditionalLine / avarageWidth) - 10) / 4;
		if (((lengthAdditionalLine / avarageWidth) - 10) % 4 >= 2) {
			roughVersion++;
		}

		return roughVersion;

		
	}
	
	static int calcExactVersion(Point[] centers, int[] angle, int[] moduleSize, boolean[][] image) 
	throws InvalidVersionInfoException, InvalidVersionException {
		boolean[] versionInformation = new boolean[18];
		Point[] points = new Point[18];
		Point target;
		Axis axis = new Axis(angle, moduleSize[UR]); //UR
		axis.setOrigin(centers[UR]);

		for (int y = 0; y < 6; y++) {
			for (int x = 0; x < 3; x++) {
				target = axis.translate(x - 7, y - 3);
				versionInformation[x + y * 3] = image[target.getX()][target.getY()];
				points[x + y * 3] = target;
			}
		}
		canvas.drawPoints(points, Color.RED);
		
		int exactVersion = 0;
		try {
			exactVersion = checkVersionInfo(versionInformation);
		} catch (InvalidVersionInfoException e) {
			canvas.println("Version info error. now retry with other place one.");
			axis.setOrigin(centers[DL]);
			axis.setModulePitch(moduleSize[DL]); //DL
			
			for (int x = 0; x < 6; x++) {
				for (int y = 0; y < 3; y++) {
					target = axis.translate(x - 3, y - 7);
					versionInformation[y + x * 3] = image[target.getX()][target.getY()];
					points[x + y * 3] = target;
				}
			}
			canvas.drawPoints(points, Color.RED);
			
			try {
				exactVersion = checkVersionInfo(versionInformation);
			} catch (VersionInformationException e2) {
				throw e2;
			}
		}
		return exactVersion;
	}
	
	static int checkVersionInfo(boolean[] target)
			throws InvalidVersionInfoException{
		// note that this method includes BCH 18-6 Error Correction
		// see page 67 on JIS-X-0510(2004) 
		int errorCount = 0, versionBase;
		for (versionBase = 0; versionBase < VersionInfoBit.length; versionBase++) {
			errorCount = 0;
			for (int j = 0; j < 18; j++) {
				if (target[j] ^ (VersionInfoBit[versionBase] >> j) % 2 == 1)
					errorCount++;
			}
			if (errorCount <= 3) break;
		}
		if (errorCount <= 3)
			return 7 + versionBase;
		else
			throw new InvalidVersionInfoException("Too many errors in version information");
	}
}