33 lines
974 B
C++
33 lines
974 B
C++
#include <mbgl/util/image.hpp>
|
|
#include <mbgl/util/string.hpp>
|
|
#include <mbgl/util/premultiply.hpp>
|
|
|
|
namespace mbgl {
|
|
|
|
PremultipliedImage decodePNG(const uint8_t*, size_t);
|
|
PremultipliedImage decodeJPEG(const uint8_t*, size_t);
|
|
|
|
PremultipliedImage decodeImage(const std::string& string) {
|
|
const auto* data = reinterpret_cast<const uint8_t*>(string.data());
|
|
const size_t size = string.size();
|
|
|
|
if (size >= 4) {
|
|
uint32_t magic = (static_cast<uint32_t>(data[0]) << 24) | (static_cast<uint32_t>(data[1]) << 16) |
|
|
(static_cast<uint32_t>(data[2]) << 8) | static_cast<uint32_t>(data[3]);
|
|
if (magic == 0x89504E47U) {
|
|
return decodePNG(data, size);
|
|
}
|
|
}
|
|
|
|
if (size >= 2) {
|
|
uint16_t magic = ((data[0] << 8) | data[1]) & 0xffff;
|
|
if (magic == 0xFFD8) {
|
|
return decodeJPEG(data, size);
|
|
}
|
|
}
|
|
|
|
throw std::runtime_error("unsupported image type");
|
|
}
|
|
|
|
} // namespace mbgl
|