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LibGfx: Factorize handling of miscellaneous and tables segments

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Miscellaneous and tables segments can also be placed between scans,
placing this code in a function will allow us to avoid duplication when
we get there.
This commit is contained in:
Lucas CHOLLET 2023-02-19 20:28:39 -05:00 • committed by Andreas Kling
parent 90573652fd
commit f1aa189027
1 changed files with 54 additions and 27 deletions
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81
Userland/Libraries/LibGfx/JPEGLoader.cpp
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@ -1099,6 +1099,55 @@ static ErrorOr<void> compose_bitmap(JPEGLoadingContext& context, Vector<Macroblo
return {};
}
static bool is_app_marker(Marker const marker)
{
return marker >= JPEG_APPN0 && marker <= JPEG_APPNF;
}
static bool is_miscellaneous_or_table_marker(Marker const marker)
{
// B.6 - Summary
// See: Figure B.17 – Flow of marker segment
bool const is_misc = marker == JPEG_COM || marker == JPEG_DRI || is_app_marker(marker);
bool const is_table = marker == JPEG_DQT || marker == JPEG_DAC || marker == JPEG_DHT;
return is_misc || is_table;
}
static ErrorOr<void> handle_miscellaneous_or_table(AK::SeekableStream& stream, JPEGLoadingContext& context, Marker const marker)
{
if (is_app_marker(marker)) {
TRY(read_app_marker(stream, context, marker - JPEG_APPN0));
return {};
}
switch (marker) {
case JPEG_COM:
case JPEG_DAC:
dbgln_if(JPEG_DEBUG, "TODO: implement marker \"{:x}\"", marker);
if (auto result = skip_segment(stream); result.is_error()) {
dbgln_if(JPEG_DEBUG, "{}: Error skipping marker: {:x}!", TRY(stream.tell()), marker);
return result.release_error();
}
break;
case JPEG_DHT:
TRY(read_huffman_table(stream, context));
break;
case JPEG_DQT:
TRY(read_quantization_table(stream, context));
break;
case JPEG_DRI:
TRY(read_restart_interval(stream, context));
break;
default:
dbgln("Unexpected marker: {:x}", marker);
VERIFY_NOT_REACHED();
}
return {};
}
static ErrorOr<void> parse_header(AK::SeekableStream& stream, JPEGLoadingContext& context)
{
auto marker = TRY(read_marker_at_cursor(stream));
@ -1109,6 +1158,11 @@ static ErrorOr<void> parse_header(AK::SeekableStream& stream, JPEGLoadingContext
for (;;) {
marker = TRY(read_marker_at_cursor(stream));
if (is_miscellaneous_or_table_marker(marker)) {
TRY(handle_miscellaneous_or_table(stream, context, marker));
continue;
}
// Set frame type if the marker marks a new frame.
if (is_frame_marker(marker))
context.frame.type = static_cast<StartOfFrame::FrameType>(marker & 0xF);
@ -1127,37 +1181,10 @@ static ErrorOr<void> parse_header(AK::SeekableStream& stream, JPEGLoadingContext
case JPEG_EOI:
dbgln_if(JPEG_DEBUG, "{}: Unexpected marker {:x}!", TRY(stream.tell()), marker);
return Error::from_string_literal("Unexpected marker");
case JPEG_APPN0:
case JPEG_APPN1:
case JPEG_APPN2:
case JPEG_APPN3:
case JPEG_APPN4:
case JPEG_APPN5:
case JPEG_APPN6:
case JPEG_APPN7:
case JPEG_APPN8:
case JPEG_APPN9:
case JPEG_APPNA:
case JPEG_APPNB:
case JPEG_APPNC:
case JPEG_APPND:
case JPEG_APPNE:
case JPEG_APPNF:
TRY(read_app_marker(stream, context, marker - JPEG_APPN0));
break;
case JPEG_SOF0:
TRY(read_start_of_frame(stream, context));
context.state = JPEGLoadingContext::FrameDecoded;
break;
case JPEG_DQT:
TRY(read_quantization_table(stream, context));
break;
case JPEG_DRI:
TRY(read_restart_interval(stream, context));
break;
case JPEG_DHT:
TRY(read_huffman_table(stream, context));
break;
case JPEG_SOS:
return read_start_of_scan(stream, context);
default: