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Implement writing png pixmaps

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This commit is contained in:
Nikita Lisitsa 2023-06-06 13:21:50 +03:00
parent 769b5786ae
commit 93e5691d8a
2 changed files with 109 additions and 55 deletions
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2
libs/gfx/include/psemek/gfx/pixmap.hpp
View file

@ -27,6 +27,8 @@ namespace psemek::gfx
pixmap_rgba read_png(io::istream && is);
pixmap_monochrome read_png_monochrome(io::istream && is);
void write_png(pixmap_rgba const & p, io::ostream && os);
template <typename Pixel, std::size_t N>
auto to_srgb(util::array<Pixel, N> pm, float g = 1.f / 2.2f)
{

162
libs/gfx/source/png.cpp
View file

@ -8,76 +8,123 @@
namespace psemek::gfx
{
template <typename Pixel>
basic_pixmap<Pixel> read_png_impl(io::istream & is, bool monochrome)
namespace
{
png_error_ptr error = [](png_structp, png_const_charp str)
template <typename Pixel>
basic_pixmap<Pixel> read_png_impl(io::istream & is, bool monochrome)
{
throw std::runtime_error(str);
};
png_error_ptr error = [](png_structp, png_const_charp str)
{
throw std::runtime_error(str);
};
png_error_ptr warn = [](png_structp, png_const_charp str)
png_error_ptr warn = [](png_structp, png_const_charp str)
{
log::warning() << str;
};
auto png = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, error, warn);
if (!png) throw std::runtime_error("png_create_read_struct returned null");
png_set_error_fn(png, nullptr, error, warn);
png_infop info = nullptr;
png_infop end_info = nullptr;
[[maybe_unused]] auto png_dtor = util::at_scope_exit([&]{
png_destroy_read_struct(&png, &info, &end_info);
});
info = png_create_info_struct(png);
if (!info) throw std::runtime_error("png_create_info_struct returned null");
end_info = png_create_info_struct(png);
if (!end_info) throw std::runtime_error("png_create_info_struct returned null");
png_rw_ptr read = [](png_structp png, png_bytep ptr, size_t count){
reinterpret_cast<io::istream *>(png_get_io_ptr(png))->read(reinterpret_cast<char *>(ptr), count);
};
png_set_read_fn(png, &is, read);
png_read_info(png, info);
auto const width = png_get_image_width(png, info);
auto const height = png_get_image_height(png, info);
auto const color_type = png_get_color_type(png, info);
auto const bit_depth = png_get_bit_depth(png, info);
if (bit_depth == 16)
png_set_strip_16(png);
if (monochrome && color_type != PNG_COLOR_TYPE_GRAY)
throw std::runtime_error("invalid color type for monochrome PNG");
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand_gray_1_2_4_to_8(png);
if (color_type == PNG_COLOR_TYPE_RGB)
png_set_add_alpha(png, 0xff, PNG_FILLER_AFTER);
png_read_update_info(png, info);
basic_pixmap<Pixel> result({width, height});
auto const row_bytes = png_get_rowbytes(png, info);
if (row_bytes != width * sizeof(Pixel))
throw std::runtime_error("PNG row bytes mismatch");
for (std::uint32_t i = 0; i < height; ++i)
png_read_row(png, reinterpret_cast<png_bytep>(result.data() + i * width), nullptr);
return result;
}
void write_png_impl(pixmap_rgba const & p, io::ostream & os)
{
log::warning() << str;
};
png_error_ptr error = [](png_structp, png_const_charp str)
{
throw std::runtime_error(str);
};
auto png = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, error, warn);
if (!png) throw std::runtime_error("png_create_read_struct returned null");
png_error_ptr warn = [](png_structp, png_const_charp str)
{
log::warning() << str;
};
png_set_error_fn(png, nullptr, error, warn);
auto png = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, error, warn);
if (!png) throw std::runtime_error("png_create_write_struct returned null");
png_infop info = nullptr;
png_infop end_info = nullptr;
png_set_error_fn(png, nullptr, error, warn);
[[maybe_unused]] auto png_dtor = util::at_scope_exit([&]{
png_destroy_read_struct(&png, &info, &end_info);
});
png_infop info = nullptr;
info = png_create_info_struct(png);
if (!info) throw std::runtime_error("png_create_info_struct returned null");
[[maybe_unused]] auto png_dtor = util::at_scope_exit([&]{
png_destroy_write_struct(&png, &info);
});
end_info = png_create_info_struct(png);
if (!end_info) throw std::runtime_error("png_create_info_struct returned null");
info = png_create_info_struct(png);
if (!info) throw std::runtime_error("png_create_info_struct returned null");
png_rw_ptr read = [](png_structp png, png_bytep ptr, size_t count){
reinterpret_cast<io::istream *>(png_get_io_ptr(png))->read(reinterpret_cast<char *>(ptr), count);
};
png_set_read_fn(png, &is, read);
png_rw_ptr write = [](png_structp png, png_bytep ptr, size_t count){
reinterpret_cast<io::ostream *>(png_get_io_ptr(png))->write(reinterpret_cast<char const *>(ptr), count);
};
png_flush_ptr flush = [](png_structp png){
reinterpret_cast<io::ostream *>(png_get_io_ptr(png))->flush();
};
png_set_write_fn(png, &os, write, flush);
png_read_info(png, info);
png_set_IHDR(png, info, p.width(), p.height(), 8, PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
auto const width = png_get_image_width(png, info);
auto const height = png_get_image_height(png, info);
auto const color_type = png_get_color_type(png, info);
auto const bit_depth = png_get_bit_depth(png, info);
png_write_info(png, info);
if (bit_depth == 16)
png_set_strip_16(png);
for (std::uint32_t i = 0; i < p.height(); ++i)
png_write_row(png, reinterpret_cast<png_byte const *>(p.data() + p.width() * i));
}
if (monochrome && color_type != PNG_COLOR_TYPE_GRAY)
throw std::runtime_error("invalid color type for monochrome PNG");
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand_gray_1_2_4_to_8(png);
if (color_type == PNG_COLOR_TYPE_RGB)
png_set_add_alpha(png, 0xff, PNG_FILLER_AFTER);
png_read_update_info(png, info);
basic_pixmap<Pixel> result({width, height});
auto const row_bytes = png_get_rowbytes(png, info);
if (row_bytes != width * sizeof(Pixel))
throw std::runtime_error("PNG row bytes mismatch");
for (std::uint32_t i = 0; i < height; ++i)
png_read_row(png, reinterpret_cast<png_bytep>(result.data() + i * width), nullptr);
return result;
}
pixmap_rgba read_png(io::istream && is)
@ -90,4 +137,9 @@ namespace psemek::gfx
return read_png_impl<std::uint8_t>(is, true);
}
void write_png(pixmap_rgba const & p, io::ostream && os)
{
write_png_impl(p, os);
}
}