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LibGfx: Commonize functions in P*MLoader class implementations

Problem:
- Functions are duplicated in [PBM,PGM,PPM]Loader class
  implementations. They are functionally equivalent. This does not
  follow the DRY (Don't Repeat Yourself) principle.

Solution:
- Factor out the common functions into a separate file.
- Refactor common code to generic functions.
- Change `PPM_DEBUG` macro to be `PORTABLE_IMAGE_LOADER_DEBUG` to work
  with all the supported types. This requires adding the image type to
  the debug log messages for easier debugging.
This commit is contained in:
Lenny Maiorani 2020-12-20 10:19:03 -07:00 committed by Andreas Kling
parent 6fac1abac4
commit a95d230a3e
6 changed files with 367 additions and 685 deletions

View file

@ -25,6 +25,7 @@
*/
#include "PBMLoader.h"
#include "PortableImageLoaderCommon.h"
#include "Streamer.h"
#include <AK/Endian.h>
#include <AK/LexicalPath.h>
@ -37,8 +38,8 @@ namespace Gfx {
struct PBMLoadingContext {
enum Type {
Unknown,
P1_ASCII,
P4_RAWBITS
ASCII,
RAWBITS
};
enum State {
@ -51,6 +52,10 @@ struct PBMLoadingContext {
Decoded
};
static constexpr auto ascii_magic_number = '1';
static constexpr auto binary_magic_number = '4';
static constexpr auto image_type = "PBM";
Type type { Type::Unknown };
State state { State::NotDecoded };
const u8* data { nullptr };
@ -60,138 +65,12 @@ struct PBMLoadingContext {
RefPtr<Gfx::Bitmap> bitmap;
};
static int read_number(Streamer& streamer)
{
u8 byte;
StringBuilder sb;
while (streamer.read(byte)) {
if (byte == ' ' || byte == '\t' || byte == '\n' || byte == '\r') {
streamer.step_back();
break;
}
sb.append(byte);
}
return sb.to_string().to_uint().value_or(0);
}
static bool read_comment([[maybe_unused]] PBMLoadingContext& context, Streamer& streamer)
{
bool exist = false;
u8 byte;
while (streamer.read(byte)) {
switch (byte) {
case '#': {
exist = true;
break;
}
case '\t':
case '\n': {
return exist;
}
default:
break;
}
}
return exist;
}
static bool read_magic_number(PBMLoadingContext& context, Streamer& streamer)
{
if (context.state >= PBMLoadingContext::MagicNumber)
return true;
if (!context.data || context.data_size < 2) {
context.state = PBMLoadingContext::State::Error;
dbg() << "There is no enough data.";
return false;
}
u8 magic_number[2];
if (!streamer.read_bytes(magic_number, 2)) {
context.state = PBMLoadingContext::State::Error;
dbg() << "We can't read magic number.";
return false;
}
if (magic_number[0] == 'P' && magic_number[1] == '1') {
context.type = PBMLoadingContext::P1_ASCII;
context.state = PBMLoadingContext::MagicNumber;
return true;
}
if (magic_number[0] == 'P' && magic_number[1] == '4') {
context.type = PBMLoadingContext::P4_RAWBITS;
context.state = PBMLoadingContext::MagicNumber;
return true;
}
context.state = PBMLoadingContext::State::Error;
dbg() << "Magic number is not valid." << (char)magic_number[0] << (char)magic_number[1];
return false;
}
static bool read_white_space(PBMLoadingContext& context, Streamer& streamer)
{
bool exist = false;
u8 byte;
while (streamer.read(byte)) {
switch (byte) {
case ' ':
case '\t':
case '\n':
case '\r': {
exist = true;
break;
}
case '#': {
streamer.step_back();
read_comment(context, streamer);
break;
}
default: {
streamer.step_back();
return exist;
}
}
}
return exist;
}
static bool read_width(PBMLoadingContext& context, Streamer& streamer)
{
context.width = read_number(streamer);
if (context.width == 0) {
return false;
}
context.state = PBMLoadingContext::Width;
return true;
}
static bool read_height(PBMLoadingContext& context, Streamer& streamer)
{
context.height = read_number(streamer);
if (context.height == 0) {
return false;
}
context.state = PBMLoadingContext::Height;
return true;
}
static bool read_image_data(PBMLoadingContext& context, Streamer& streamer)
{
u8 byte;
Vector<Gfx::Color> color_data;
if (context.type == PBMLoadingContext::P1_ASCII) {
if (context.type == PBMLoadingContext::ASCII) {
while (streamer.read(byte)) {
if (byte == '0') {
color_data.append(Color::White);
@ -199,7 +78,7 @@ static bool read_image_data(PBMLoadingContext& context, Streamer& streamer)
color_data.append(Color::Black);
}
}
} else if (context.type == PBMLoadingContext::P4_RAWBITS) {
} else if (context.type == PBMLoadingContext::RAWBITS) {
size_t color_index = 0;
while (streamer.read(byte)) {
@ -222,83 +101,24 @@ static bool read_image_data(PBMLoadingContext& context, Streamer& streamer)
}
}
context.bitmap = Bitmap::create_purgeable(BitmapFormat::RGB32, { context.width, context.height });
if (!context.bitmap) {
context.state = PBMLoadingContext::State::Error;
if (!create_bitmap(context)) {
return false;
}
size_t index = 0;
for (int y = 0; y < context.height; ++y) {
for (int x = 0; x < context.width; ++x) {
context.bitmap->set_pixel(x, y, color_data.at(index));
index++;
}
}
set_pixels(context, color_data);
context.state = PBMLoadingContext::State::Bitmap;
return true;
}
static bool decode_pbm(PBMLoadingContext& context)
{
if (context.state >= PBMLoadingContext::State::Decoded)
return true;
Streamer streamer(context.data, context.data_size);
if (!read_magic_number(context, streamer))
return false;
if (!read_white_space(context, streamer))
return false;
if (!read_width(context, streamer))
return false;
if (!read_white_space(context, streamer))
return false;
if (!read_height(context, streamer))
return false;
if (!read_white_space(context, streamer))
return false;
if (!read_image_data(context, streamer))
return false;
context.state = PBMLoadingContext::State::Decoded;
return true;
}
static RefPtr<Gfx::Bitmap> load_pbm_impl(const u8* data, size_t data_size)
{
PBMLoadingContext context;
context.data = data;
context.data_size = data_size;
if (!decode_pbm(context))
return nullptr;
return context.bitmap;
}
RefPtr<Gfx::Bitmap> load_pbm(const StringView& path)
{
MappedFile mapped_file(path);
if (!mapped_file.is_valid()) {
return nullptr;
}
auto bitmap = load_pbm_impl((const u8*)mapped_file.data(), mapped_file.size());
if (bitmap)
bitmap->set_mmap_name(String::format("Gfx::Bitmap [%dx%d] - Decoded PBM: %s", bitmap->width(), bitmap->height(), LexicalPath::canonicalized_path(path).characters()));
return bitmap;
return load<PBMLoadingContext>(path);
}
RefPtr<Gfx::Bitmap> load_pbm_from_memory(const u8* data, size_t length)
{
auto bitmap = load_pbm_impl(data, length);
auto bitmap = load_impl<PBMLoadingContext>(data, length);
if (bitmap)
bitmap->set_mmap_name(String::format("Gfx::Bitmap [%dx%d] - Decoded PBM: <memory>", bitmap->width(), bitmap->height()));
return bitmap;
@ -321,7 +141,7 @@ IntSize PBMImageDecoderPlugin::size()
return {};
if (m_context->state < PBMLoadingContext::State::Decoded) {
bool success = decode_pbm(*m_context);
bool success = decode(*m_context);
if (!success)
return {};
}
@ -335,7 +155,7 @@ RefPtr<Gfx::Bitmap> PBMImageDecoderPlugin::bitmap()
return nullptr;
if (m_context->state < PBMLoadingContext::State::Decoded) {
bool success = decode_pbm(*m_context);
bool success = decode(*m_context);
if (!success)
return nullptr;
}