ladybird/Userland/Libraries/LibGfx/ImageFormats/ILBMLoader.cpp

475 lines
16 KiB
C++

/*
* Copyright (c) 2023, Nicolas Ramz <nicolas.ramz@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/ByteReader.h>
#include <AK/Debug.h>
#include <AK/Endian.h>
#include <AK/FixedArray.h>
#include <AK/IntegralMath.h>
#include <LibCompress/PackBitsDecoder.h>
#include <LibGfx/FourCC.h>
#include <LibGfx/ImageFormats/ILBMLoader.h>
namespace Gfx {
struct IFFHeader {
FourCC form;
BigEndian<u32> file_size;
FourCC format;
};
static_assert(AssertSize<IFFHeader, 12>());
struct Chunk {
FourCC type;
ReadonlyBytes data;
};
enum class CompressionType : u8 {
None = 0,
ByteRun = 1,
__Count
};
enum class MaskType : u8 {
None = 0,
HasMask = 1,
HasTransparentColor = 2,
HasLasso = 3,
__Count
};
enum class ViewportMode : u32 {
EHB = 0x80,
HAM = 0x800
};
enum class Format : u8 {
// Amiga interleaved format
ILBM = 0,
// PC-DeluxePaint chunky format
PBM = 1
};
AK_ENUM_BITWISE_OPERATORS(ViewportMode);
struct ChunkHeader {
FourCC chunk_type;
BigEndian<u32> chunk_size;
};
struct BMHDHeader {
BigEndian<u16> width;
BigEndian<u16> height;
BigEndian<i16> x;
BigEndian<i16> y;
u8 planes;
MaskType mask;
CompressionType compression;
u8 pad;
BigEndian<u16> transparent_color;
u8 x_aspect;
u8 y_aspect;
BigEndian<u16> page_width;
BigEndian<u16> page_height;
};
static_assert(sizeof(BMHDHeader) == 20);
struct ILBMLoadingContext {
enum class State {
NotDecoded = 0,
HeaderDecoded,
BitmapDecoded
};
State state { State::NotDecoded };
ReadonlyBytes data;
// points to current chunk
ReadonlyBytes chunks_cursor;
// max number of bytes per plane row
u16 pitch;
ViewportMode viewport_mode;
Vector<Color> color_table;
// number of bits needed to describe current palette
u8 cmap_bits;
RefPtr<Gfx::Bitmap> bitmap;
BMHDHeader bm_header;
Format format;
};
static ErrorOr<void> decode_iff_ilbm_header(ILBMLoadingContext& context)
{
if (context.state >= ILBMLoadingContext::State::HeaderDecoded)
return {};
if (context.data.size() < sizeof(IFFHeader))
return Error::from_string_literal("Missing IFF header");
auto& header = *bit_cast<IFFHeader const*>(context.data.data());
if (header.form != FourCC("FORM") || (header.format != FourCC("ILBM") && header.format != FourCC("PBM ")))
return Error::from_string_literal("Invalid IFF-ILBM header");
context.format = header.format == FourCC("ILBM") ? Format::ILBM : Format::PBM;
return {};
}
static ErrorOr<Vector<Color>> decode_cmap_chunk(Chunk cmap_chunk)
{
size_t const size = cmap_chunk.data.size() / 3;
Vector<Color> color_table;
TRY(color_table.try_ensure_capacity(size));
for (size_t i = 0; i < size; ++i) {
color_table.unchecked_append(Color(cmap_chunk.data[i * 3], cmap_chunk.data[(i * 3) + 1], cmap_chunk.data[(i * 3) + 2]));
}
return color_table;
}
static ErrorOr<RefPtr<Gfx::Bitmap>> chunky_to_bitmap(ILBMLoadingContext& context, ByteBuffer const& chunky)
{
auto const width = context.bm_header.width;
auto const height = context.bm_header.height;
RefPtr<Gfx::Bitmap> bitmap = TRY(Bitmap::create(BitmapFormat::BGRA8888, { width, height }));
dbgln_if(ILBM_DEBUG, "created Bitmap {}x{}", width, height);
// - For 24bit pictures: the chunky buffer contains 3 bytes (R,G,B) per pixel
// - For indexed colored pictures: chunky buffer contains a single byte per pixel
u8 pixel_size = AK::max(1, context.bm_header.planes / 8);
for (int row = 0; row < height; ++row) {
// Keep color: in HAM mode, current color
// may be based on previous color instead of coming from
// the palette.
Color color = Color::Black;
for (int col = 0; col < width; col++) {
size_t index = (width * row * pixel_size) + (col * pixel_size);
if (context.bm_header.planes == 24) {
color = Color(chunky[index], chunky[index + 1], chunky[index + 2]);
} else if (chunky[index] < context.color_table.size()) {
color = context.color_table[chunky[index]];
if (context.bm_header.mask == MaskType::HasTransparentColor && chunky[index] == context.bm_header.transparent_color)
color = color.with_alpha(0);
} else if (has_flag(context.viewport_mode, ViewportMode::HAM)) {
// Get the control bit which will tell use how current pixel should be calculated
u8 control = (chunky[index] >> context.cmap_bits) & 0x3;
// Since we only have (cmap_bits - 2) bits to define the component,
// we need to pad it to 8 bits.
u8 component = (chunky[index] % context.color_table.size()) << (8 - context.cmap_bits);
if (control == 1) {
color.set_blue(component);
} else if (control == 2) {
color.set_red(component);
} else {
color.set_green(component);
}
} else {
return Error::from_string_literal("Color map index out of bounds but HAM bit not set");
}
bitmap->set_pixel(col, row, color);
}
}
dbgln_if(ILBM_DEBUG, "filled Bitmap");
return bitmap;
}
static ErrorOr<ByteBuffer> planar_to_chunky(ReadonlyBytes bitplanes, ILBMLoadingContext& context)
{
dbgln_if(ILBM_DEBUG, "planar_to_chunky");
u16 pitch = context.pitch;
u16 width = context.bm_header.width;
u16 height = context.bm_header.height;
u8 planes = context.bm_header.planes;
size_t buffer_size = static_cast<size_t>(width) * height;
// If planes number is 24 we'll store R,G,B components so buffer needs to be 3 times width*height
// otherwise we'll store a single 8bit index to the CMAP.
if (planes == 24)
buffer_size *= 3;
auto chunky = TRY(ByteBuffer::create_zeroed(buffer_size));
u8 const pixel_size = AK::max(1, planes / 8);
for (u16 y = 0; y < height; y++) {
size_t scanline = static_cast<size_t>(y) * width;
for (u8 p = 0; p < planes; p++) {
u8 const plane_mask = 1 << (p % 8);
size_t offset_base = (pitch * planes * y) + (p * pitch);
if (offset_base + pitch > bitplanes.size())
return Error::from_string_literal("Malformed bitplane data");
for (u16 i = 0; i < pitch; i++) {
u8 bit = bitplanes[offset_base + i];
u8 rgb_shift = p / 8;
// Only throw an error if we would actually attempt to write
// outside of the chunky buffer. Some apps like PPaint produce
// malformed bitplane data but files are still accepted by most readers.
if (bit && scanline + ((pitch - 1) * 8) + 7 >= chunky.size())
return Error::from_string_literal("Malformed bitplane data");
for (u8 b = 0; b < 8; b++) {
u8 mask = 1 << (7 - b);
// get current plane
if (bit & mask) {
u16 x = (i * 8) + b;
chunky[(scanline * pixel_size) + (x * pixel_size) + rgb_shift] |= plane_mask;
}
}
}
}
}
dbgln_if(ILBM_DEBUG, "planar_to_chunky: end");
return chunky;
}
static ErrorOr<ByteBuffer> uncompress_byte_run(ReadonlyBytes data, ILBMLoadingContext& context)
{
auto length = data.size();
dbgln_if(ILBM_DEBUG, "uncompress_byte_run pitch={} size={}", context.pitch, data.size());
size_t plane_data_size = context.pitch * context.bm_header.height * context.bm_header.planes;
// The maximum run length of this compression method is 127 bytes, so the uncompressed size
// cannot be more than 127 times the size of the chunk we are decompressing.
if (plane_data_size > NumericLimits<u32>::max() || ceil_div(plane_data_size, 127ul) > length)
return Error::from_string_literal("Uncompressed data size too large");
auto plane_data = TRY(Compress::PackBits::decode_all(data, plane_data_size));
return plane_data;
}
static ErrorOr<void> extend_ehb_palette(ILBMLoadingContext& context)
{
dbgln_if(ILBM_DEBUG, "need to extend palette");
for (size_t i = 0; i < 32; ++i) {
auto const color = context.color_table[i];
TRY(context.color_table.try_append(color.darkened()));
}
return {};
}
static ErrorOr<void> reduce_ham_palette(ILBMLoadingContext& context)
{
u8 bits = context.cmap_bits;
dbgln_if(ILBM_DEBUG, "reduce palette planes={} bits={}", context.bm_header.planes, context.cmap_bits);
if (bits > context.bm_header.planes) {
dbgln_if(ILBM_DEBUG, "need to reduce palette");
bits -= (bits - context.bm_header.planes) + 2;
// bits shouldn't theorically be less than 4 bits in HAM mode.
if (bits < 4)
return Error::from_string_literal("Error while reducing CMAP for HAM: bits too small");
context.color_table.resize((context.color_table.size() >> bits));
context.cmap_bits = bits;
}
return {};
}
static ErrorOr<void> decode_body_chunk(Chunk body_chunk, ILBMLoadingContext& context)
{
dbgln_if(ILBM_DEBUG, "decode_body_chunk {}", body_chunk.data.size());
ByteBuffer pixel_data;
if (context.bm_header.compression == CompressionType::ByteRun) {
auto plane_data = TRY(uncompress_byte_run(body_chunk.data, context));
if (context.format == Format::ILBM)
pixel_data = TRY(planar_to_chunky(plane_data, context));
else
pixel_data = plane_data;
} else {
if (context.format == Format::ILBM)
pixel_data = TRY(planar_to_chunky(body_chunk.data, context));
else
pixel_data = TRY(ByteBuffer::copy(body_chunk.data.data(), body_chunk.data.size()));
}
// Some files already have 64 colors defined in the palette,
// maybe for upward compatibility with 256 colors software/hardware.
// DPaint 4 & previous files only have 32 colors so the
// palette needs to be extended only for these files.
if (has_flag(context.viewport_mode, ViewportMode::EHB) && context.color_table.size() < 64) {
TRY(extend_ehb_palette(context));
} else if (has_flag(context.viewport_mode, ViewportMode::HAM)) {
TRY(reduce_ham_palette(context));
}
context.bitmap = TRY(chunky_to_bitmap(context, pixel_data));
return {};
}
static ErrorOr<Chunk> decode_iff_chunk_header(ReadonlyBytes chunks)
{
if (chunks.size() < sizeof(ChunkHeader))
return Error::from_string_literal("Not enough data for IFF chunk header");
auto const& header = *bit_cast<ChunkHeader const*>(chunks.data());
if (chunks.size() < sizeof(ChunkHeader) + header.chunk_size)
return Error::from_string_literal("Not enough data for IFF chunk");
return Chunk { header.chunk_type, { chunks.data() + sizeof(ChunkHeader), header.chunk_size } };
}
static ErrorOr<Chunk> decode_iff_advance_chunk(ReadonlyBytes& chunks)
{
auto chunk = TRY(decode_iff_chunk_header(chunks));
chunks = chunks.slice(sizeof(ChunkHeader) + chunk.data.size());
// add padding if needed
if (chunk.data.size() % 2 != 0) {
if (chunks.is_empty())
return Error::from_string_literal("Missing data for padding byte");
if (*chunks.data() != 0)
return Error::from_string_literal("Padding byte is not 0");
chunks = chunks.slice(1);
}
return chunk;
}
static ErrorOr<void> decode_iff_chunks(ILBMLoadingContext& context)
{
auto& chunks = context.chunks_cursor;
dbgln_if(ILBM_DEBUG, "decode_iff_chunks");
while (!chunks.is_empty()) {
auto chunk = TRY(decode_iff_advance_chunk(chunks));
if (chunk.type == FourCC("CMAP")) {
// Some files (HAM mainly) have CMAP chunks larger than the planes they advertise: I'm not sure
// why but we should not return an error in this case.
context.color_table = TRY(decode_cmap_chunk(chunk));
context.cmap_bits = AK::ceil_log2(context.color_table.size());
} else if (chunk.type == FourCC("BODY")) {
if (context.color_table.is_empty() && context.bm_header.planes != 24)
return Error::from_string_literal("Decoding indexed BODY chunk without a color map is not currently supported");
// Apparently 32bit ilbm files exist: but I wasn't able to find any,
// nor is it documented anywhere, so let's make it clear it's not supported.
if (context.bm_header.planes != 24 && context.bm_header.planes > 8)
return Error::from_string_literal("Invalid number of bitplanes");
TRY(decode_body_chunk(chunk, context));
context.state = ILBMLoadingContext::State::BitmapDecoded;
} else if (chunk.type == FourCC("CRNG")) {
dbgln_if(ILBM_DEBUG, "Chunk:CRNG");
} else if (chunk.type == FourCC("CAMG")) {
context.viewport_mode = static_cast<ViewportMode>(AK::convert_between_host_and_big_endian(ByteReader::load32(chunk.data.data())));
dbgln_if(ILBM_DEBUG, "Chunk:CAMG, Viewport={}, EHB={}, HAM={}", (u32)context.viewport_mode, has_flag(context.viewport_mode, ViewportMode::EHB), has_flag(context.viewport_mode, ViewportMode::HAM));
}
}
if (context.state != ILBMLoadingContext::State::BitmapDecoded)
return Error::from_string_literal("Missing body chunk");
return {};
}
static ErrorOr<void> decode_bmhd_chunk(ILBMLoadingContext& context)
{
context.chunks_cursor = context.data.slice(sizeof(IFFHeader));
auto first_chunk = TRY(decode_iff_advance_chunk(context.chunks_cursor));
if (first_chunk.type != FourCC("BMHD"))
return Error::from_string_literal("IFFImageDecoderPlugin: Invalid chunk type, expected BMHD");
if (first_chunk.data.size() < sizeof(BMHDHeader))
return Error::from_string_literal("IFFImageDecoderPlugin: Not enough data for header chunk");
context.bm_header = *bit_cast<BMHDHeader const*>(first_chunk.data.data());
if (context.bm_header.mask >= MaskType::__Count)
return Error::from_string_literal("IFFImageDecoderPlugin: Unsupported mask type");
if (context.bm_header.compression >= CompressionType::__Count)
return Error::from_string_literal("IFFImageDecoderPlugin: Unsupported compression type");
context.pitch = ceil_div((u16)context.bm_header.width, (u16)16) * 2;
context.state = ILBMLoadingContext::State::HeaderDecoded;
dbgln_if(ILBM_DEBUG, "IFFImageDecoderPlugin: BMHD: {}x{} ({},{}), p={}, m={}, c={}",
context.bm_header.width,
context.bm_header.height,
context.bm_header.x,
context.bm_header.y,
context.bm_header.planes,
to_underlying(context.bm_header.mask),
to_underlying(context.bm_header.compression));
return {};
}
ILBMImageDecoderPlugin::ILBMImageDecoderPlugin(ReadonlyBytes data, NonnullOwnPtr<ILBMLoadingContext> context)
: m_context(move(context))
{
m_context->data = data;
}
ILBMImageDecoderPlugin::~ILBMImageDecoderPlugin() = default;
IntSize ILBMImageDecoderPlugin::size()
{
return IntSize { m_context->bm_header.width, m_context->bm_header.height };
}
bool ILBMImageDecoderPlugin::sniff(ReadonlyBytes data)
{
ILBMLoadingContext context;
context.data = data;
return !decode_iff_ilbm_header(context).is_error();
}
ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> ILBMImageDecoderPlugin::create(ReadonlyBytes data)
{
auto context = TRY(try_make<ILBMLoadingContext>());
auto plugin = TRY(adopt_nonnull_own_or_enomem(new (nothrow) ILBMImageDecoderPlugin(data, move(context))));
TRY(decode_iff_ilbm_header(*plugin->m_context));
TRY(decode_bmhd_chunk(*plugin->m_context));
return plugin;
}
ErrorOr<ImageFrameDescriptor> ILBMImageDecoderPlugin::frame(size_t index, Optional<IntSize>)
{
if (index > 0)
return Error::from_string_literal("ILBMImageDecoderPlugin: frame index must be 0");
if (m_context->state < ILBMLoadingContext::State::BitmapDecoded)
TRY(decode_iff_chunks(*m_context));
VERIFY(m_context->bitmap);
return ImageFrameDescriptor { m_context->bitmap, 0 };
}
}