46 lines
1.4 KiB
C++
46 lines
1.4 KiB
C++
#include <mbgl/util/image.hpp>
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#include <mbgl/util/string.hpp>
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#include <mbgl/util/premultiply.hpp>
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namespace mbgl {
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#if !defined(__ANDROID__) && !defined(__APPLE__)
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PremultipliedImage decodeWebP(const uint8_t*, size_t);
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#endif // !defined(__ANDROID__) && !defined(__APPLE__)
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PremultipliedImage decodePNG(const uint8_t*, size_t);
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PremultipliedImage decodeJPEG(const uint8_t*, size_t);
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PremultipliedImage decodeImage(const std::string& string) {
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const auto* data = reinterpret_cast<const uint8_t*>(string.data());
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const size_t size = string.size();
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#if !defined(__ANDROID__) && !defined(__APPLE__)
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if (size >= 12) {
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uint32_t riff_magic = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
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uint32_t webp_magic = (data[8] << 24) | (data[9] << 16) | (data[10] << 8) | data[11];
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if (riff_magic == 0x52494646 && webp_magic == 0x57454250) {
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return decodeWebP(data, size);
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}
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}
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#endif // !defined(__ANDROID__) && !defined(__APPLE__)
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if (size >= 4) {
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uint32_t magic = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
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if (magic == 0x89504E47U) {
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return decodePNG(data, size);
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}
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}
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if (size >= 2) {
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uint16_t magic = ((data[0] << 8) | data[1]) & 0xffff;
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if (magic == 0xFFD8) {
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return decodeJPEG(data, size);
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}
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}
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throw std::runtime_error("unsupported image type");
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}
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} // namespace mbgl
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