banan-os/userspace/libraries/LibImage/Image.cpp

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#include <BAN/ScopeGuard.h>
#include <BAN/String.h>
#include <LibImage/Image.h>
#include <LibImage/Netbpm.h>
#include <LibImage/PNG.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/mman.h>
namespace LibImage
{
BAN::ErrorOr<BAN::UniqPtr<Image>> Image::load_from_file(BAN::StringView path)
{
int fd = -1;
if (path.data()[path.size()] == '\0')
{
fd = open(path.data(), O_RDONLY);
}
else
{
BAN::String path_str;
TRY(path_str.append(path));
fd = open(path_str.data(), O_RDONLY);
}
if (fd == -1)
{
fprintf(stddbg, "open: %s\n", strerror(errno));
return BAN::Error::from_errno(errno);
}
BAN::ScopeGuard guard_file_close([fd] { close(fd); });
struct stat st;
if (fstat(fd, &st) == -1)
{
fprintf(stddbg, "fstat: %s\n", strerror(errno));
return BAN::Error::from_errno(errno);
}
void* addr = mmap(nullptr, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (addr == MAP_FAILED)
{
fprintf(stddbg, "mmap: %s\n", strerror(errno));
return BAN::Error::from_errno(errno);
}
BAN::ScopeGuard guard_munmap([&] { munmap(addr, st.st_size); });
auto image_data_span = BAN::ConstByteSpan(reinterpret_cast<uint8_t*>(addr), st.st_size);
if (probe_netbpm(image_data_span))
return TRY(load_netbpm(image_data_span));
if (probe_png(image_data_span))
return TRY(load_png(image_data_span));
fprintf(stderr, "unrecognized image format\n");
return BAN::Error::from_errno(ENOTSUP);
}
struct FloatingColor
{
double r, g, b, a;
constexpr FloatingColor() {}
constexpr FloatingColor(double r, double g, double b, double a)
: r(r), g(g), b(b), a(a)
{}
constexpr FloatingColor(Image::Color c)
: r(c.r), g(c.g), b(c.b), a(c.a)
{}
constexpr FloatingColor operator*(double value) const
{
return FloatingColor(r * value, g * value, b * value, a * value);
}
constexpr FloatingColor operator+(FloatingColor other) const
{
return FloatingColor(r + other.r, g + other.g, b + other.b, a + other.a);
}
constexpr Image::Color as_color() const
{
return Image::Color {
.r = static_cast<uint8_t>(BAN::Math::clamp<double>(r, 0.0, 255.0)),
.g = static_cast<uint8_t>(BAN::Math::clamp<double>(g, 0.0, 255.0)),
.b = static_cast<uint8_t>(BAN::Math::clamp<double>(b, 0.0, 255.0)),
.a = static_cast<uint8_t>(BAN::Math::clamp<double>(a, 0.0, 255.0)),
};
}
};
BAN::ErrorOr<BAN::UniqPtr<Image>> Image::resize(uint64_t new_width, uint64_t new_height, ResizeAlgorithm algorithm)
{
if (!validate_size(new_width, new_height))
return BAN::Error::from_errno(EOVERFLOW);
const double ratio_x = (double)width() / new_width;
const double ratio_y = (double)height() / new_height;
const auto get_clamped_color =
[this](int64_t x, int64_t y)
{
x = BAN::Math::clamp<int64_t>(x, 0, width() - 1);
y = BAN::Math::clamp<int64_t>(y, 0, height() - 1);
return get_color(x, y);
};
switch (algorithm)
{
case ResizeAlgorithm::Nearest:
{
BAN::Vector<Color> nearest_bitmap;
TRY(nearest_bitmap.resize(new_width * new_height));
for (uint64_t y = 0; y < new_height; y++)
for (uint64_t x = 0; x < new_width; x++)
nearest_bitmap[y * new_width + x] = get_clamped_color(x * ratio_x, y * ratio_y);
return TRY(BAN::UniqPtr<Image>::create(new_width, new_height, BAN::move(nearest_bitmap)));
}
case ResizeAlgorithm::Linear:
{
BAN::Vector<Color> bilinear_bitmap;
TRY(bilinear_bitmap.resize(new_width * new_height));
for (uint64_t y = 0; y < new_height; y++)
{
for (uint64_t x = 0; x < new_width; x++)
{
const double src_x = x * ratio_x;
const double src_y = y * ratio_y;
const double weight_x = src_x - floor(src_x);
const double weight_y = src_y - floor(src_y);
const Color avg_t = Color::average(
get_clamped_color(src_x + 0.0, src_y),
get_clamped_color(src_x + 1.0, src_y),
weight_x
);
const Color avg_b = Color::average(
get_clamped_color(src_x + 0.0, src_y + 1.0),
get_clamped_color(src_x + 0.0, src_y + 1.0),
weight_x
);
bilinear_bitmap[y * new_width + x] = Color::average(avg_t, avg_b, weight_y);
}
}
return TRY(BAN::UniqPtr<Image>::create(new_width, new_height, BAN::move(bilinear_bitmap)));
}
case ResizeAlgorithm::Cubic:
{
BAN::Vector<Color> bicubic_bitmap;
TRY(bicubic_bitmap.resize(new_width * new_height));
constexpr auto cubic_interpolate =
[](FloatingColor p[4], double x)
{
const auto a = (p[0] * -0.5) + (p[1] * 1.5) + (p[2] * -1.5) + (p[3] * 0.5);
const auto b = p[0] + (p[1] * -2.5) + (p[2] * 2.0) + (p[3] * -0.5);
const auto c = (p[0] * -0.5) + (p[2] * 0.5);
const auto d = p[1];
return (a * x * x * x) + (b * x * x) + (c * x) + d;
};
for (uint64_t y = 0; y < new_height; y++)
{
for (uint64_t x = 0; x < new_width; x++)
{
const double src_x = x * ratio_x;
const double src_y = y * ratio_y;
const double weight_x = src_x - floor(src_x);
const double weight_y = src_y - floor(src_y);
FloatingColor values[4];
for (int64_t m = -1; m <= 2; m++)
{
FloatingColor p[4];
p[0] = get_clamped_color(src_x - 1.0, src_y + m);
p[1] = get_clamped_color(src_x + 0.0, src_y + m);
p[2] = get_clamped_color(src_x + 1.0, src_y + m);
p[3] = get_clamped_color(src_x + 2.0, src_y + m);
values[m + 1] = cubic_interpolate(p, weight_x);
}
bicubic_bitmap[y * new_width + x] = cubic_interpolate(values, weight_y).as_color();
}
}
return TRY(BAN::UniqPtr<Image>::create(new_width, new_height, BAN::move(bicubic_bitmap)));
}
}
return BAN::Error::from_errno(EINVAL);
}
}