void ArrayTest::access() {
Array a(7);
for(std::size_t i = 0; i != 7; ++i)
a[i] = i;
CORRADE_COMPARE(a.data(), static_cast<int*>(a));
CORRADE_COMPARE(*(a.begin()+2), 2);
CORRADE_COMPARE(a[4], 4);
CORRADE_COMPARE(a.end()-a.begin(), a.size());
const auto b = Array::from(7, 3, 5, 4);
CORRADE_COMPARE(b.data(), static_cast<const int*>(b));
CORRADE_COMPARE(b[2], 5);
}
std::optional<ImageData2D> JpegImporter::doImage2D(UnsignedInt) {
/* Initialize structures */
jpeg_decompress_struct file;
Containers::Array<JSAMPROW> rows;
Containers::Array<char> data;
/* Fugly error handling stuff */
/** @todo Get rid of this crap */
struct ErrorManager {
jpeg_error_mgr jpegErrorManager;
std::jmp_buf setjmpBuffer;
} errorManager;
file.err = jpeg_std_error(&errorManager.jpegErrorManager);
errorManager.jpegErrorManager.error_exit = [](j_common_ptr info) {
info->err->output_message(info);
std::longjmp(reinterpret_cast<ErrorManager*>(info->err)->setjmpBuffer, 1);
};
if(setjmp(errorManager.setjmpBuffer)) {
Error() << "Trade::JpegImporter::image2D(): error while reading JPEG file";
jpeg_destroy_decompress(&file);
return std::nullopt;
}
/* Open file */
jpeg_create_decompress(&file);
jpeg_mem_src(&file, _in.begin(), _in.size());
/* Read file header, start decompression */
jpeg_read_header(&file, true);
jpeg_start_decompress(&file);
/* Image size and type */
const Vector2i size(file.output_width, file.output_height);
static_assert(BITS_IN_JSAMPLE == 8, "Only 8-bit JPEG is supported");
constexpr PixelType type = PixelType::UnsignedByte;
/* Image format */
PixelFormat format = {};
switch(file.out_color_space) {
case JCS_GRAYSCALE:
CORRADE_INTERNAL_ASSERT(file.out_color_components == 1);
#ifdef MAGNUM_TARGET_GLES2
format = Context::hasCurrent() && Context::current().isExtensionSupported<Extensions::GL::EXT::texture_rg>() ?
PixelFormat::Red : PixelFormat::Luminance;
#else
format = PixelFormat::Red;
#endif
break;
case JCS_RGB:
CORRADE_INTERNAL_ASSERT(file.out_color_components == 3);
format = PixelFormat::RGB;
break;
/** @todo RGBA (only in libjpeg-turbo and probably ignored) */
default:
Error() << "Trade::JpegImporter::image2D(): unsupported color space" << file.out_color_space;
return std::nullopt;
}
/* Initialize data array, align rows to four bytes */
const std::size_t stride = ((size.x()*file.out_color_components*BITS_IN_JSAMPLE/8 + 3)/4)*4;
data = Containers::Array<char>{stride*std::size_t(size.y())};
/* Read image row by row */
rows = Containers::Array<JSAMPROW>{std::size_t(size.y())};
for(Int i = 0; i != size.y(); ++i)
rows[i] = reinterpret_cast<JSAMPROW>(data.data()) + (size.y() - i - 1)*stride;
while(file.output_scanline < file.output_height)
jpeg_read_scanlines(&file, rows + file.output_scanline, file.output_height - file.output_scanline);
/* Cleanup */
jpeg_finish_decompress(&file);
jpeg_destroy_decompress(&file);
/* Always using the default 4-byte alignment */
return Trade::ImageData2D{format, type, size, std::move(data)};
}
Containers::Optional<ImageData2D> JpegImporter::doImage2D(UnsignedInt) {
/* Initialize structures */
jpeg_decompress_struct file;
Containers::Array<char> data;
/* Fugly error handling stuff */
/** @todo Get rid of this crap */
struct ErrorManager {
jpeg_error_mgr jpegErrorManager;
std::jmp_buf setjmpBuffer;
char message[JMSG_LENGTH_MAX]{};
} errorManager;
file.err = jpeg_std_error(&errorManager.jpegErrorManager);
errorManager.jpegErrorManager.error_exit = [](j_common_ptr info) {
auto& errorManager = *reinterpret_cast<ErrorManager*>(info->err);
info->err->format_message(info, errorManager.message);
std::longjmp(errorManager.setjmpBuffer, 1);
};
if(setjmp(errorManager.setjmpBuffer)) {
Error() << "Trade::JpegImporter::image2D(): error:" << errorManager.message;
jpeg_destroy_decompress(&file);
return Containers::NullOpt;
}
/* Open file */
jpeg_create_decompress(&file);
jpeg_mem_src(&file, _in.begin(), _in.size());
/* Read file header, start decompression. On macOS (Travis, with Xcode 7.3)
the compilation fails because "no known conversion from 'bool' to
'boolean' for 2nd argument" (boolean is an enum instead of a typedef to
int there) so doing the conversion implicitly. */
jpeg_read_header(&file, boolean(true));
jpeg_start_decompress(&file);
/* Image size and type */
const Vector2i size(file.output_width, file.output_height);
static_assert(BITS_IN_JSAMPLE == 8, "Only 8-bit JPEG is supported");
/* Image format */
PixelFormat format;
switch(file.out_color_space) {
case JCS_GRAYSCALE:
CORRADE_INTERNAL_ASSERT(file.out_color_components == 1);
format = PixelFormat::R8Unorm;
break;
case JCS_RGB:
CORRADE_INTERNAL_ASSERT(file.out_color_components == 3);
format = PixelFormat::RGB8Unorm;
break;
/** @todo RGBA (only in libjpeg-turbo and probably ignored) */
default:
Error() << "Trade::JpegImporter::image2D(): unsupported color space" << file.out_color_space;
return Containers::NullOpt;
}
/* Initialize data array, align rows to four bytes */
const std::size_t stride = ((size.x()*file.out_color_components*BITS_IN_JSAMPLE/8 + 3)/4)*4;
data = Containers::Array<char>{stride*std::size_t(size.y())};
/* Read image row by row */
while(file.output_scanline < file.output_height) {
JSAMPROW row = reinterpret_cast<JSAMPROW>(data.data() + (size.y() - file.output_scanline - 1)*stride);
jpeg_read_scanlines(&file, &row, 1);
}
/* Cleanup */
jpeg_finish_decompress(&file);
jpeg_destroy_decompress(&file);
/* Always using the default 4-byte alignment */
return Trade::ImageData2D{format, size, std::move(data)};
}
