sethLabels/glbarcode/BarcodeCode39.cpp

/*  BarcodeCode39.cpp
 *
 *  Copyright (C) 2013  Jaye Evins <evins@snaught.com>
 *
 *  This file is part of glbarcode++.
 *
 *  glbarcode++ is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  glbarcode++ is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with glbarcode++.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "BarcodeCode39.h"

#include "Constants.h"

#include <cctype>
#include <algorithm>


using namespace glbarcode::Constants;


namespace
{
	/* Code 39 alphabet. Position indicates value. */
	const std::string alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%";

	/* Code 39 symbols. Position must match position in alphabet. */
	const std::string symbols[] = {
		/*        BsBsBsBsB */
		/* 0 */  "NnNwWnWnN",
		/* 1 */  "WnNwNnNnW",
		/* 2 */  "NnWwNnNnW",
		/* 3 */  "WnWwNnNnN",
		/* 4 */  "NnNwWnNnW",
		/* 5 */  "WnNwWnNnN",
		/* 6 */  "NnWwWnNnN",
		/* 7 */  "NnNwNnWnW",
		/* 8 */  "WnNwNnWnN",
		/* 9 */  "NnWwNnWnN",
		/* A */  "WnNnNwNnW",
		/* B */  "NnWnNwNnW",
		/* C */  "WnWnNwNnN",
		/* D */  "NnNnWwNnW",
		/* E */  "WnNnWwNnN",
		/* F */  "NnWnWwNnN",
		/* G */  "NnNnNwWnW",
		/* H */  "WnNnNwWnN",
		/* I */  "NnWnNwWnN",
		/* J */  "NnNnWwWnN",
		/* K */  "WnNnNnNwW",
		/* L */  "NnWnNnNwW",
		/* M */  "WnWnNnNwN",
		/* N */  "NnNnWnNwW",
		/* O */  "WnNnWnNwN",
		/* P */  "NnWnWnNwN",
		/* Q */  "NnNnNnWwW",
		/* R */  "WnNnNnWwN",
		/* S */  "NnWnNnWwN",
		/* T */  "NnNnWnWwN",
		/* U */  "WwNnNnNnW",
		/* V */  "NwWnNnNnW",
		/* W */  "WwWnNnNnN",
		/* X */  "NwNnWnNnW",
		/* Y */  "WwNnWnNnN",
		/* Z */  "NwWnWnNnN",
		/* - */  "NwNnNnWnW",
		/* . */  "WwNnNnWnN",
		/*   */  "NwWnNnWnN",
		/* $ */  "NwNwNwNnN",
		/* / */  "NwNwNnNwN",
		/* + */  "NwNnNwNwN",
		/* % */  "NnNwNwNwN"
	};

	const std::string frameSymbol = "NwNnWnWnN";

	/* Vectorization constants */
	const double MIN_X       = ( 0.0075 *  PTS_PER_INCH );
	const double N           = 2.5;
	const double MIN_I       = MIN_X;
	const double MIN_HEIGHT  = ( 0.19685 *  PTS_PER_INCH );
	const double MIN_QUIET   = ( 10 * MIN_X );

	const double MIN_TEXT_AREA_HEIGHT = 12.0;
	const double MIN_TEXT_SIZE        = 8.0;

}


namespace glbarcode
{

	/*
	 * Static Code39 barcode creation method
	 */
	Barcode* BarcodeCode39::create( )
	{
		return new BarcodeCode39();
	}


	/*
	 * Code39 data validation, implements Barcode1dBase::validate()
	 */
	bool BarcodeCode39::validate( const std::string& rawData )
	{
		for (char r : rawData)
		{
			char c = toupper( r );

			if ( alphabet.find(c) == std::string::npos )
			{
				return false;
			}
		}

		return true;
	}


	/*
	 * Code39 data encoding, implements Barcode1dBase::encode()
	 */
	std::string BarcodeCode39::encode( const std::string& cookedData )
	{
		std::string code;

		/* Left frame symbol */
		code += frameSymbol;
		code += "i";

		int sum = 0;
		for (char c : cookedData)
		{
			size_t cValue = alphabet.find( toupper( c ) );

			code += symbols[cValue];
			code += "i";

			sum += int(cValue);
		}

		if ( checksum() )
		{
			code += symbols[sum % 43];
			code += "i";
		}

		/* Right frame bar */
		code += frameSymbol;

		return code;
	}


	/*
	 * Code39 prepare text for display, implements Barcode1dBase::prepareText()
	 */
	std::string BarcodeCode39::prepareText( const std::string& rawData )
	{
		std::string displayText;

		for (char c : rawData)
		{
			displayText += toupper( c );
		}

		return displayText;
	}


	/*
	 * Code39 vectorization, implements Barcode1dBase::vectorize()
	 */
	void BarcodeCode39::vectorize( const std::string& codedData,
	                               const std::string& displayText,
	                               const std::string& cookedData,
	                               double&            w,
	                               double&            h )
	{

		/* determine width and establish horizontal scale, based on original cooked data */
		auto dataSize = double( cookedData.size() );
		double minL;
		if ( !checksum() )
		{
			minL = (dataSize + 2)*(3*N + 6)*MIN_X + (dataSize + 1)*MIN_I;
		}
		else
		{
			minL = (dataSize + 3)*(3*N + 6)*MIN_X + (dataSize + 2)*MIN_I;
		}
        
		double scale;
		if ( w == 0 )
		{
			scale = 1.0;
		}
		else
		{
			scale = w / (minL + 2*MIN_QUIET);

			if ( scale < 1.0 )
			{
				scale = 1.0;
			}
		}
		double width = minL * scale;

		/* determine text parameters */
		double hTextArea = scale * MIN_TEXT_AREA_HEIGHT;
		double textSize   = scale * MIN_TEXT_SIZE;

		/* determine height of barcode */
		double height = showText() ? h - hTextArea : h;
		height = std::max( height, std::max( 0.15*width, MIN_HEIGHT ) );

		/* determine horizontal quiet zone */
		double xQuiet = std::max( (10 * scale * MIN_X), MIN_QUIET );

		/* Now traverse the code string and draw each bar */
		double x1 = xQuiet;
		for (char c : codedData)
		{
			double lwidth;
				
			switch ( c )
			{

			case 'i':
				/* Inter-character gap */
				x1 += scale * MIN_I;
				break;

			case 'N':
				/* Narrow bar */
				lwidth = scale*MIN_X;
				addLine( x1, 0.0, lwidth, height );
				x1 += scale * MIN_X;
				break;

			case 'W':
				/* Wide bar */
				lwidth = scale*N*MIN_X;
				addLine( x1, 0.0, lwidth, height );
				x1 += scale * N * MIN_X;
				break;

			case 'n':
				/* Narrow space */
				x1 += scale * MIN_X;
				break;

			case 'w':
				/* Wide space */
				x1 += scale * N * MIN_X;
				break;

			default:
				// NOT REACHED
				break;
			}
		}

		if ( showText() )
		{
			std::string starredText = "*" + displayText + "*";
			addText( xQuiet + width/2, height + (hTextArea+0.7*textSize)/2, textSize, starredText );
		}

		/* Overwrite requested size with actual size. */
		w = width + 2*xQuiet;
		h = showText() ? height + hTextArea : height;

	}

}