ladybird/Userland/Libraries/LibGfx/TGALoader.cpp
Nico Weber 307712b398 LibGfx: Add a method to ImageDecoderPlugin for reading ICC data
This probably won't be the final API for getting color spaces
from images, since some formats just store an "is sRGB?" flag
instead of a full profile. Instead, once everything works,
we probably want to give every Bitmap a pointer to some
color space abstraction.

But we can always change this later, once things are further along
and better understood.
2023-01-27 17:26:48 +00:00

368 lines
11 KiB
C++

/*
* Copyright (c) 2022, Tom Needham <06needhamt@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Span.h>
#include <AK/StdLibExtraDetails.h>
#include <AK/String.h>
#include <LibGfx/TGALoader.h>
namespace Gfx {
enum TGADataType : u8 {
None = 0,
UncompressedColorMapped = 1,
UncompressedRGB = 2,
UncompressedBlackAndWhite = 3,
RunLengthEncodedColorMapped = 9,
RunLengthEncodedRGB = 10,
CompressedBlackAndWhite = 11,
CompressedColorMapped = 32,
CompressedColorMappedFourPass = 33
};
struct [[gnu::packed]] TGAHeader {
u8 id_length;
u8 color_map_type;
TGADataType data_type_code;
i16 color_map_origin;
i16 color_map_length;
u8 color_map_depth;
i16 x_origin;
i16 y_origin;
u16 width;
u16 height;
u8 bits_per_pixel;
u8 image_descriptor;
};
static_assert(sizeof(TGAHeader) == 18);
union [[gnu::packed]] TGAPixel {
struct TGAColor {
u8 blue;
u8 green;
u8 red;
u8 alpha;
} components;
u32 data;
};
struct TGAPixelPacket {
bool raw;
u8 pixels_count;
};
static_assert(AssertSize<TGAPixel, 4>());
class TGAReader {
public:
TGAReader(ReadonlyBytes data)
: m_data(move(data))
{
}
TGAReader(ReadonlyBytes data, size_t index)
: m_data(move(data))
, m_index(index)
{
}
ALWAYS_INLINE u8 read_u8()
{
u8 value = m_data[m_index];
m_index++;
return value;
}
ALWAYS_INLINE i8 read_i8()
{
return static_cast<i8>(read_u8());
}
ALWAYS_INLINE u16 read_u16()
{
return read_u8() | read_u8() << 8;
}
ALWAYS_INLINE i16 read_i16()
{
return read_i8() | read_i8() << 8;
}
ALWAYS_INLINE u32 read_u32()
{
return read_u16() | read_u16() << 16;
}
ALWAYS_INLINE i32 read_i32()
{
return read_i16() | read_i16() << 16;
}
ALWAYS_INLINE TGAPixelPacket read_packet_type()
{
auto pixel_packet_type = read_u8();
auto pixel_packet = TGAPixelPacket();
pixel_packet.raw = !(pixel_packet_type & 0x80);
pixel_packet.pixels_count = (pixel_packet_type & 0x7f);
// NOTE: Run-length-encoded/Raw pixel packets cannot encode zero pixels,
// so value 0 stands for 1 pixel, 1 stands for 2, etc...
pixel_packet.pixels_count++;
return pixel_packet;
}
ALWAYS_INLINE TGAPixel read_pixel(u8 bits_per_pixel)
{
auto pixel = TGAPixel();
switch (bits_per_pixel) {
case 24:
pixel.components.blue = read_u8();
pixel.components.green = read_u8();
pixel.components.red = read_u8();
pixel.components.alpha = 0xFF;
return pixel;
case 32:
pixel.components.blue = read_u8();
pixel.components.green = read_u8();
pixel.components.red = read_u8();
pixel.components.alpha = read_u8();
return pixel;
default:
VERIFY_NOT_REACHED();
}
}
size_t index() const
{
return m_index;
}
ReadonlyBytes data() const
{
return m_data;
}
private:
ReadonlyBytes m_data;
size_t m_index { 0 };
};
struct TGALoadingContext {
TGAHeader header;
OwnPtr<TGAReader> reader = { nullptr };
RefPtr<Gfx::Bitmap> bitmap;
};
TGAImageDecoderPlugin::TGAImageDecoderPlugin(u8 const* file_data, size_t file_size)
{
m_context = make<TGALoadingContext>();
m_context->reader = make<TGAReader>(ReadonlyBytes { file_data, file_size });
}
TGAImageDecoderPlugin::~TGAImageDecoderPlugin() = default;
IntSize TGAImageDecoderPlugin::size()
{
return IntSize { m_context->header.width, m_context->header.height };
}
void TGAImageDecoderPlugin::set_volatile()
{
if (m_context->bitmap)
m_context->bitmap->set_volatile();
}
bool TGAImageDecoderPlugin::set_nonvolatile(bool& was_purged)
{
if (!m_context->bitmap)
return false;
return m_context->bitmap->set_nonvolatile(was_purged);
}
bool TGAImageDecoderPlugin::decode_tga_header()
{
auto& reader = m_context->reader;
if (reader->data().size() < sizeof(TGAHeader))
return false;
m_context->header = TGAHeader();
m_context->header.id_length = reader->read_u8();
m_context->header.color_map_type = reader->read_u8();
m_context->header.data_type_code = static_cast<TGADataType>(reader->read_u8());
m_context->header.color_map_origin = reader->read_i16();
m_context->header.color_map_length = reader->read_i16();
m_context->header.color_map_depth = reader->read_u8();
m_context->header.x_origin = reader->read_i16();
m_context->header.y_origin = reader->read_i16();
m_context->header.width = reader->read_u16();
m_context->header.height = reader->read_u16();
m_context->header.bits_per_pixel = reader->read_u8();
m_context->header.image_descriptor = reader->read_u8();
auto bytes_remaining = reader->data().size() - reader->index();
if (m_context->header.data_type_code == TGADataType::UncompressedRGB && bytes_remaining < (m_context->header.width * m_context->header.height * (m_context->header.bits_per_pixel / 8)))
return false;
if (m_context->header.bits_per_pixel < 8 || m_context->header.bits_per_pixel > 32)
return false;
return true;
}
bool TGAImageDecoderPlugin::initialize()
{
return decode_tga_header();
}
ErrorOr<bool> TGAImageDecoderPlugin::validate_before_create(ReadonlyBytes data)
{
if (data.size() < sizeof(TGAHeader))
return false;
TGAHeader const& header = *reinterpret_cast<TGAHeader const*>(data.data());
if (header.data_type_code == TGADataType::UncompressedRGB && data.size() < (header.width * header.height * (header.bits_per_pixel / 8)))
return false;
if (header.bits_per_pixel < 8 || header.bits_per_pixel > 32)
return false;
return true;
}
ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> TGAImageDecoderPlugin::create(ReadonlyBytes data)
{
return adopt_nonnull_own_or_enomem(new (nothrow) TGAImageDecoderPlugin(data.data(), data.size()));
}
bool TGAImageDecoderPlugin::is_animated()
{
return false;
}
size_t TGAImageDecoderPlugin::loop_count()
{
return 0;
}
size_t TGAImageDecoderPlugin::frame_count()
{
return 1;
}
ErrorOr<ImageFrameDescriptor> TGAImageDecoderPlugin::frame(size_t index)
{
auto bits_per_pixel = m_context->header.bits_per_pixel;
auto color_map = m_context->header.color_map_type;
auto data_type = m_context->header.data_type_code;
auto width = m_context->header.width;
auto height = m_context->header.height;
auto x_origin = m_context->header.x_origin;
auto y_origin = m_context->header.y_origin;
if (index != 0)
return Error::from_string_literal("TGAImageDecoderPlugin: frame index must be 0");
if (color_map > 1)
return Error::from_string_literal("TGAImageDecoderPlugin: Invalid color map type");
if (m_context->bitmap) {
return ImageFrameDescriptor { m_context->bitmap, 0 };
} else {
// NOTE: Just to be on the safe side, if m_context->bitmap is nullptr, then
// just re-construct the reader object. This will ensure that if the bitmap
// was set as volatile and therefore it is gone, we can always re-generate it
// with a new call to this method!
VERIFY(m_context->reader);
m_context->reader = make<TGAReader>(m_context->reader->data(), sizeof(TGAHeader));
}
RefPtr<Gfx::Bitmap> bitmap;
switch (bits_per_pixel) {
case 24:
bitmap = TRY(Bitmap::create(BitmapFormat::BGRx8888, { m_context->header.width, m_context->header.height }));
break;
case 32:
bitmap = TRY(Bitmap::create(BitmapFormat::BGRA8888, { m_context->header.width, m_context->header.height }));
break;
default:
// FIXME: Implement other TGA bit depths
return Error::from_string_literal("TGAImageDecoderPlugin: Can only handle 24 and 32 bits per pixel");
}
// FIXME: Try to understand the Image origin (instead of X and Y origin coordinates)
// based on the Image descriptor, Field 5.6, bits 4 and 5.
// NOTE: If Y origin is set to a negative number, just assume the generating software
// meant that we start with Y origin at the top height of the picture.
// At least this is the observed behavior when generating some pictures in GIMP.
if (y_origin < 0)
y_origin = height;
if (y_origin != 0 && y_origin != height)
return Error::from_string_literal("TGAImageDecoderPlugin: Can only handle Y origin which is 0 or the entire height");
if (x_origin != 0 && x_origin != width)
return Error::from_string_literal("TGAImageDecoderPlugin: Can only handle X origin which is 0 or the entire width");
switch (data_type) {
case TGADataType::UncompressedRGB: {
for (int row = 0; row < height; ++row) {
for (int col = 0; col < width; ++col) {
auto pixel = m_context->reader->read_pixel(bits_per_pixel);
auto actual_row = row;
if (y_origin < height)
actual_row = height - 1 - row;
auto actual_col = col;
if (x_origin > width)
actual_col = width - 1 - col;
bitmap->scanline(actual_row)[actual_col] = pixel.data;
}
}
break;
}
case TGADataType::RunLengthEncodedRGB: {
size_t pixel_index = 0;
size_t pixel_count = height * width;
while (pixel_index < pixel_count) {
auto packet_type = m_context->reader->read_packet_type();
VERIFY(packet_type.pixels_count > 0);
TGAPixel pixel = m_context->reader->read_pixel(bits_per_pixel);
auto max_pixel_index = min(pixel_index + packet_type.pixels_count, pixel_count);
for (size_t current_pixel_index = pixel_index; current_pixel_index < max_pixel_index; ++current_pixel_index) {
int row = current_pixel_index / width;
int col = current_pixel_index % width;
auto actual_row = row;
if (y_origin < height)
actual_row = height - 1 - row;
auto actual_col = col;
if (x_origin > width)
actual_col = width - 1 - col;
bitmap->scanline(actual_row)[actual_col] = pixel.data;
if (packet_type.raw && (current_pixel_index + 1) < max_pixel_index)
pixel = m_context->reader->read_pixel(bits_per_pixel);
}
pixel_index += packet_type.pixels_count;
}
break;
}
default:
// FIXME: Implement other TGA data types
return Error::from_string_literal("TGAImageDecoderPlugin: Can currently only handle the UncompressedRGB or CompressedRGB data type");
}
m_context->bitmap = bitmap;
return ImageFrameDescriptor { m_context->bitmap, 0 };
}
ErrorOr<Optional<ReadonlyBytes>> TGAImageDecoderPlugin::icc_data()
{
return OptionalNone {};
}
}