QR-Code-scanner: integrate QUIRC library, implement QrDecoder, drop ZBar

src/QR-Code-scanner/Decoder.cpp

@@ -0,0 +1,71 @@
+#include "Decoder.h"
+
+#include <limits>
+
+#include "quirc.h"
+
+QrDecoder::QrDecoder()
+    : m_qr(quirc_new())
+{
+    if (m_qr == nullptr)
+    {
+        throw std::runtime_error("QUIRC: failed to allocate memory");
+    }
+}
+
+QrDecoder::~QrDecoder()
+{
+    quirc_destroy(m_qr);
+}
+
+std::vector<std::string> QrDecoder::decode(const QImage &image)
+{
+    if (image.format() == QImage::Format_Grayscale8)
+    {
+        return decodeGrayscale8(image);
+    }
+    return decodeGrayscale8(image.convertToFormat(QImage::Format_Grayscale8));
+}
+
+std::vector<std::string> QrDecoder::decodeGrayscale8(const QImage &image)
+{
+    if (quirc_resize(m_qr, image.width(), image.height()) < 0)
+    {
+        throw std::runtime_error("QUIRC: failed to allocate video memory");
+    }
+
+    uint8_t *rawImage = quirc_begin(m_qr, nullptr, nullptr);
+    if (rawImage == nullptr)
+    {
+        throw std::runtime_error("QUIRC: failed to get image buffer");
+    }
+#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+    std::copy(image.constBits(), image.constBits() + image.sizeInBytes(), rawImage);
+#else
+    std::copy(image.constBits(), image.constBits() + image.byteCount(), rawImage);
+#endif
+    quirc_end(m_qr);
+
+    const int count = quirc_count(m_qr);
+    if (count < 0)
+    {
+        throw std::runtime_error("QUIRC: failed to get the number of recognized QR-codes");
+    }
+
+    std::vector<std::string> result;
+    result.reserve(static_cast<size_t>(count));
+    for (int index = 0; index < count; ++index)
+    {
+        quirc_code code;
+        quirc_extract(m_qr, index, &code);
+
+        quirc_data data;
+        const quirc_decode_error_t err = quirc_decode(&code, &data);
+        if (err == QUIRC_SUCCESS)
+        {
+            result.emplace_back(&data.payload[0], &data.payload[data.payload_len]);
+        }
+    }
+
+    return result;
+}