diff options
Diffstat (limited to 'platform/default/png_reader.cpp')
-rw-r--r-- | platform/default/png_reader.cpp | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/platform/default/png_reader.cpp b/platform/default/png_reader.cpp new file mode 100644 index 0000000000..1780ecf23c --- /dev/null +++ b/platform/default/png_reader.cpp @@ -0,0 +1,279 @@ +#include "mbgl/util/image_reader.hpp" +#include <iostream> +extern "C" +{ +#include <png.h> +} +// boost +#pragma GCC diagnostic push +//#pragma GCC diagnostic ignored "-Wunused-local-typedef" +#include <boost/iostreams/device/file.hpp> +#include <boost/iostreams/device/array.hpp> +#include <boost/iostreams/stream.hpp> +#pragma GCC diagnostic pop + +// stl +#include <cstring> +#include <memory> + +namespace mbgl { namespace util { + +template <typename T> +class png_reader : public image_reader +{ + using source_type = T; + using input_stream = boost::iostreams::stream<source_type>; + + struct png_struct_guard + { + png_struct_guard(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) + : p_(png_ptr_ptr), + i_(info_ptr_ptr) {} + + ~png_struct_guard() + { + png_destroy_read_struct(p_,i_,0); + } + png_structpp p_; + png_infopp i_; + }; + +private: + + source_type source_; + input_stream stream_; + unsigned width_; + unsigned height_; + int bit_depth_; + int color_type_; + bool has_alpha_; +public: + explicit png_reader(std::string const& file_name); + png_reader(char const* data, std::size_t size); + ~png_reader(); + unsigned width() const; + unsigned height() const; + inline bool has_alpha() const { return has_alpha_; } + bool premultiplied_alpha() const { return false; } //http://www.libpng.org/pub/png/spec/1.1/PNG-Rationale.html + void read(unsigned x,unsigned y, unsigned width, unsigned height, char * image); +private: + void init(); + static void png_read_data(png_structp png_ptr, png_bytep data, png_size_t length); +}; + +namespace +{ + +image_reader* create_png_reader(std::string const& file) +{ + return new png_reader<boost::iostreams::file_source>(file); +} + +image_reader* create_png_reader2(char const * data, std::size_t size) +{ + return new png_reader<boost::iostreams::array_source>(data, size); +} + +const bool registered = register_image_reader("png",create_png_reader); +const bool registered2 = register_image_reader("png", create_png_reader2); +} + + +void user_error_fn(png_structp /*png_ptr*/, png_const_charp error_msg) +{ + throw image_reader_exception(std::string("failed to read invalid png: '") + error_msg + "'"); +} + +void user_warning_fn(png_structp /*png_ptr*/, png_const_charp warning_msg) +{ + fprintf(stderr, "ImageReader (PNG): %s\n", warning_msg); + +} + +template <typename T> +void png_reader<T>::png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + input_stream * fin = reinterpret_cast<input_stream*>(png_get_io_ptr(png_ptr)); + fin->read(reinterpret_cast<char*>(data), length); + std::streamsize read_count = fin->gcount(); + if (read_count < 0 || static_cast<png_size_t>(read_count) != length) + { + png_error(png_ptr, "Read Error"); + } +} + +template <typename T> +png_reader<T>::png_reader(std::string const& file_name) + : source_(file_name,std::ios_base::in | std::ios_base::binary), + stream_(source_), + width_(0), + height_(0), + bit_depth_(0), + color_type_(0), + has_alpha_(false) +{ + if (!source_.is_open()) throw image_reader_exception("PNG reader: cannot open file '"+ file_name + "'"); + if (!stream_) throw image_reader_exception("PNG reader: cannot open file '"+ file_name + "'"); + init(); +} + +template <typename T> +png_reader<T>::png_reader(char const* data, std::size_t size) + : source_(data,size), + stream_(source_), + width_(0), + height_(0), + bit_depth_(0), + color_type_(0), + has_alpha_(false) +{ + + if (!stream_) throw image_reader_exception("PNG reader: cannot open image stream"); + init(); +} + + +template <typename T> +png_reader<T>::~png_reader() {} + + +template <typename T> +void png_reader<T>::init() +{ + png_byte header[8]; + std::memset(header,0,8); + stream_.read(reinterpret_cast<char*>(header),8); + if ( stream_.gcount() != 8) + { + throw image_reader_exception("PNG reader: Could not read image"); + } + int is_png=!png_sig_cmp(header,0,8); + if (!is_png) + { + throw image_reader_exception("File or stream is not a png"); + } + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING,0,0,0); + + if (!png_ptr) + { + throw image_reader_exception("failed to allocate png_ptr"); + } + + // catch errors in a custom way to avoid the need for setjmp + png_set_error_fn(png_ptr, png_get_error_ptr(png_ptr), user_error_fn, user_warning_fn); + + png_infop info_ptr; + png_struct_guard sguard(&png_ptr,&info_ptr); + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) throw image_reader_exception("failed to create info_ptr"); + + png_set_read_fn(png_ptr, (png_voidp)&stream_, png_read_data); + + png_set_sig_bytes(png_ptr,8); + png_read_info(png_ptr, info_ptr); + + png_uint_32 width, height; + png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth_, &color_type_,0,0,0); + has_alpha_ = (color_type_ & PNG_COLOR_MASK_ALPHA) || png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS); + width_=width; + height_=height; + + //MAPNIK_LOG_DEBUG(png_reader) << "png_reader: bit_depth=" << bit_depth_ << ",color_type=" << color_type_; +} + +template <typename T> +unsigned png_reader<T>::width() const +{ + return width_; +} + +template <typename T> +unsigned png_reader<T>::height() const +{ + return height_; +} + +template <typename T> +void png_reader<T>::read(unsigned x0, unsigned y0, unsigned width, unsigned height, char * image) +{ + stream_.clear(); + stream_.seekg(0, std::ios_base::beg); + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING,0,0,0); + + if (!png_ptr) + { + throw image_reader_exception("failed to allocate png_ptr"); + } + + // catch errors in a custom way to avoid the need for setjmp + png_set_error_fn(png_ptr, png_get_error_ptr(png_ptr), user_error_fn, user_warning_fn); + + png_infop info_ptr; + png_struct_guard sguard(&png_ptr,&info_ptr); + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) throw image_reader_exception("failed to create info_ptr"); + + png_set_read_fn(png_ptr, (png_voidp)&stream_, png_read_data); + png_read_info(png_ptr, info_ptr); + + if (color_type_ == PNG_COLOR_TYPE_PALETTE) + png_set_expand(png_ptr); + if (color_type_ == PNG_COLOR_TYPE_GRAY && bit_depth_ < 8) + png_set_expand(png_ptr); + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) + png_set_expand(png_ptr); + if (bit_depth_ == 16) + png_set_strip_16(png_ptr); + if (color_type_ == PNG_COLOR_TYPE_GRAY || + color_type_ == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + + // quick hack -- only work in >=libpng 1.2.7 + png_set_add_alpha(png_ptr,0xff,PNG_FILLER_AFTER); //rgba + + double gamma; + if (png_get_gAMA(png_ptr, info_ptr, &gamma)) + png_set_gamma(png_ptr, 2.2, gamma); + + if (x0 == 0 && y0 == 0 && width >= width_ && height >= height_) + { + if (png_get_interlace_type(png_ptr,info_ptr) == PNG_INTERLACE_ADAM7) + { + png_set_interlace_handling(png_ptr); // FIXME: libpng bug? + // according to docs png_read_image + // "..automatically handles interlacing, + // so you don't need to call png_set_interlace_handling()" + } + png_read_update_info(png_ptr, info_ptr); + // we can read whole image at once + // alloc row pointers + const std::unique_ptr<png_bytep[]> rows(new png_bytep[height_]); + for (unsigned row = 0; row < height_; ++row) + rows[row] = (png_bytep)image + row * width_ ; + png_read_image(png_ptr, rows.get()); + } + else + { + png_read_update_info(png_ptr, info_ptr); + //unsigned w=std::min(width, width_ - x0); + unsigned h=std::min(height, height_ - y0); + unsigned rowbytes=png_get_rowbytes(png_ptr, info_ptr); + const std::unique_ptr<png_byte[]> row(new png_byte[rowbytes]); + //START read image rows + for (unsigned i = 0; i < height_; ++i) + { + png_read_row(png_ptr,row.get(),0); + if (i >= y0 && i < (y0 + h)) + { +////image.setRow(i-y0,reinterpret_cast<unsigned*>(&row[x0 * 4]),w); + //std::copy(image, buf + size, pData_ + i * width); + } + } + //END + } + png_read_end(png_ptr,0); +} +}} |