Add option to change error correction level in MultiFormatWriter

README.md

@@ -75,6 +75,8 @@ emmake make
 
 See usage example of exported functions from a demo here: https://nu-book.github.io/zxing-cpp/demo.html.
 
+By default, both encoder and decoder are included. If you don't plan to use either of them, you can disable it to reduce generated code size. To do so, in the line `emconfigure cmake ...` above, pass `-ENABLE_ENCODERS=0` to disable encoders or `-ENABLE_DECODERS=0` to disable decoders.
+
 ### For other platforms
 Wrappers are provided as convenient way to work with native image format. You still can use the library without a wrapper.
 

core/src/MultiFormatWriter.cpp

@@ -20,6 +20,7 @@
 #include "datamatrix/DMWriter.h"
 #include "pdf417/PDFWriter.h"
 #include "qrcode/QRWriter.h"
+#include "qrcode/QRErrorCorrectionLevel.h"
 #include "oned/ODCodabarWriter.h"
 #include "oned/ODCode39Writer.h"
 #include "oned/ODCode93Writer.h"
@@ -34,12 +35,14 @@ namespace ZXing {
 
 namespace {
 
-	template <typename Writer>
-	Writer CreateWriter(CharacterSet encoding)
+	template <typename Writer, typename EccConverter>
+	Writer CreateWriter(CharacterSet encoding, int eccLevel)
 	{
 		Writer writer;
 		if (encoding != CharacterSet::Unknown)
 			writer.setEncoding(encoding);
+		if (eccLevel >= 0 && eccLevel <= 8)
+			writer.setEccPercent(EccConverter()(eccLevel));
 		return writer;
 	}
 
@@ -52,17 +55,45 @@ namespace {
 		return writer;
 	}
 
-	template <typename Writer>
-	Writer CreateWriter(CharacterSet encoding, int margin)
+	template <typename Writer, typename EccConverter>
+	Writer CreateWriter(CharacterSet encoding, int margin, int eccLevel)
 	{
 		Writer writer;
 		if (encoding != CharacterSet::Unknown)
 			writer.setEncoding(encoding);
 		if (margin >= 0)
 			writer.setMargin(margin);
+		if (eccLevel >= 0 && eccLevel <= 8)
+			writer.setErrorCorrectionLevel(EccConverter()(eccLevel));
 		return writer;
 	}
 
+	struct AztecEccConverter {
+		int operator()(int eccLevel) const {
+			// Aztec supports levels 0 to 100 in percentage
+			return eccLevel * 100 / 8;
+		}
+	};
+
+	struct Pdf417EccConverter {
+		int operator()(int eccLevel) const {
+			return eccLevel;
+		}
+	};
+
+	struct QRCodeEccConverter {
+		QRCode::ErrorCorrectionLevel operator()(int eccPercent) const {
+			if (eccPercent <= 1)
+				return QRCode::ErrorCorrectionLevel::Low;
+			else if (eccPercent <= 4)
+				return QRCode::ErrorCorrectionLevel::Medium;
+			else if (eccPercent <= 6)
+				return QRCode::ErrorCorrectionLevel::Quality;
+			else
+				return QRCode::ErrorCorrectionLevel::High;
+		}
+	};
+
 } // anonymous
 
 BitMatrix
@@ -71,13 +102,13 @@ MultiFormatWriter::encode(const std::wstring& contents, int width, int height) c
 	switch (_format)
 	{
 	case BarcodeFormat::AZTEC:
-		return CreateWriter<Aztec::Writer>(_encoding).encode(contents, width, height);
+		return CreateWriter<Aztec::Writer, AztecEccConverter>(_encoding, _eccLevel).encode(contents, width, height);
 	case BarcodeFormat::DATA_MATRIX:
 		return DataMatrix::Writer().encode(contents, width, height);
 	case BarcodeFormat::PDF_417:
-		return CreateWriter<Pdf417::Writer>(_encoding, _margin).encode(contents, width, height);
+		return CreateWriter<Pdf417::Writer, Pdf417EccConverter>(_encoding, _margin, _eccLevel).encode(contents, width, height);
 	case BarcodeFormat::QR_CODE:
-		return CreateWriter<QRCode::Writer>(_encoding, _margin).encode(contents, width, height);
+		return CreateWriter<QRCode::Writer, QRCodeEccConverter>(_encoding, _margin, _eccLevel).encode(contents, width, height);
 	case BarcodeFormat::CODABAR:
 		return CreateWriter<OneD::CodabarWriter>(_margin).encode(contents, width, height);
 	case BarcodeFormat::CODE_39:

core/src/MultiFormatWriter.h

@@ -40,6 +40,14 @@ class MultiFormatWriter
 		return *this;
 	}
 
+	/**
+	* Used for Aztec, PDF417, and QRCode only, [0-8].
+	*/
+	MultiFormatWriter& setEccLevel(int level) {
+		_eccLevel = level;
+		return *this;
+	}
+
 	/**
 	* Used for all 1D formats, PDF417, and QRCode only.
 	*/
@@ -54,6 +62,7 @@ class MultiFormatWriter
 	BarcodeFormat _format;
 	CharacterSet _encoding = CharacterSet::Unknown;
 	int _margin = -1;
+	int _eccLevel = -1;
 };
 
 } // ZXing

example/generate_png.cpp

@@ -32,10 +32,11 @@ using namespace ZXing;
 
 static void PrintUsage(const char* exePath)
 {
-    std::cout << "Usage: " << exePath << " [-size <width>x<height>] [-margin <margin>] [-encoding <encoding>] <format> <text> <output>" << std::endl
+    std::cout << "Usage: " << exePath << " [-size <width>x<height>] [-margin <margin>] [-encoding <encoding>] [-ecc <level>] <format> <text> <output>" << std::endl
 		<< "    -size      Size of generated image" << std::endl
 		<< "    -margin    Margin around barcode" << std::endl
 		<< "    -encoding  Encoding used to encode input text" << std::endl
+        << "    -ecc       Error correction level, [0-8]"
 		<< std::endl
 		<< "Supported formats are:" << std::endl
 		<< "    AZTEC" << std::endl
@@ -84,7 +85,7 @@ static bool ParseSize(std::string str, int* width, int* height)
 	return false;
 }
 
-static bool ParseOptions(int argc, char* argv[], int* width, int* height, int* margin, std::string* format, std::string* text, std::string* filePath)
+static bool ParseOptions(int argc, char* argv[], int* width, int* height, int* margin, int* eccLevel, std::string* format, std::string* text, std::string* filePath)
 {
 	int nonOptArgCount = 0;
 	for (int i = 1; i < argc; ++i) {
@@ -109,6 +110,15 @@ static bool ParseOptions(int argc, char* argv[], int* width, int* height, int* m
 				return false;
 			}
 		}
+		else if (strcmp(argv[i], "-ecc") == 0) {
+			if (i + 1 < argc) {
+				++i;
+				*eccLevel = std::stoi(argv[i]);
+			}
+			else {
+				return false;
+			}
+		}
 		else if (nonOptArgCount == 0) {
 			*format = ParseFormat(argv[i]);
 			if (format->empty()) {
@@ -142,9 +152,10 @@ int main(int argc, char* argv[])
 
 	int width = 100, height = 100;
 	int margin = 10;
+	int eccLevel = -1;
 	std::string format, text, filePath;
 
-	if (!ParseOptions(argc, argv, &width, &height, &margin, &format, &text, &filePath)) {
+	if (!ParseOptions(argc, argv, &width, &height, &margin, &eccLevel, &format, &text, &filePath)) {
 		PrintUsage(argv[0]);
 		return -1;
 	}
@@ -157,6 +168,8 @@ int main(int argc, char* argv[])
 		MultiFormatWriter writer(barcodeFormat);
 		if (margin >= 0)
 			writer.setMargin(margin);
+		if (eccLevel >= 0)
+			writer.setEccLevel(eccLevel);
 
 		auto matrix = writer.encode(TextUtfEncoding::FromUtf8(text), width, height);
 

wrappers/wasm/BarcodeWriter.cpp

@@ -46,7 +46,7 @@ class WriteResult
     }
 };
 
-WriteResult generateBarcode(std::wstring text, std::string format, std::string encoding, int margin, int width, int height)
+WriteResult generateBarcode(std::wstring text, std::string format, std::string encoding, int margin, int width, int height, int eccLevel)
 {
     using namespace ZXing;
 	try {
@@ -63,6 +63,10 @@ WriteResult generateBarcode(std::wstring text, std::string format, std::string e
             writer.setEncoding(charset);
         }
 
+        if (eccLevel >= 0 && eccLevel <= 8) {
+            writer.setEccLevel(eccLevel);
+        }
+
 		auto matrix = writer.encode(text, width, height);
 
 		std::vector<unsigned char> buffer(matrix.width() * matrix.height(), '\0');

wrappers/wasm/CMakeLists.txt

@@ -2,21 +2,12 @@ cmake_minimum_required (VERSION 3.1.3)
 
 project (ZXingWasm)
 
-set (ENABLE_ENCODERS ON CACHE INTERNAL "Check to include encoders")
-set (ENABLE_DECODERS ON CACHE INTERNAL "Check to include decoders")
+set (ENABLE_ENCODERS ON CACHE BOOL "Check to include encoders")
+set (ENABLE_DECODERS ON CACHE BOOL "Check to include decoders")
 
 add_definitions (-DUNICODE -D_UNICODE)
 
-if (MSVC)
-    add_definitions (-D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS -DNOMINMAX)
-
-    set (CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} /Oi /GS-")
-    set (CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /Oi /GS-")
-else()
-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra")
-    set (CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG")
-    set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -D_DEBUG")
-endif()
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra")
 
 include (CheckCXXCompilerFlag)
 CHECK_CXX_COMPILER_FLAG ("-std=c++11" COMPILER_SUPPORTS_CXX11)
@@ -27,12 +18,25 @@ endif()
 
 add_subdirectory (${CMAKE_CURRENT_SOURCE_DIR}/../../core ${CMAKE_BINARY_DIR}/ZXingCore)
 
+set (SOURCE_FILES lodepng.cpp)
+
+if (ENABLE_DECODERS)
+    set (SOURCE_FILES ${SOURCE_FILES}
+        BarcodeReader.cpp
+    )
+endif()
+
+if (ENABLE_ENCODERS)
+    set (SOURCE_FILES ${SOURCE_FILES}
+        BarcodeWriter.cpp
+    )
+endif()
+
 add_executable (zxing
-    BarcodeReader.cpp
-    BarcodeWriter.cpp
+    ${SOURCE_FILES}
     lodepng.cpp
 )
 
-set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --bind -s DISABLE_EXCEPTION_CATCHING=0")
+set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --bind -Oz -s DISABLE_EXCEPTION_CATCHING=0 -s FILESYSTEM=0")
 
 target_link_libraries (zxing ZXingCore)