chromium/third_party/libpng/pngget.c

/* pngget.c - retrieval of values from info struct
 *
 * Copyright (c) 2018-2024 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
 *
 */

#include "pngpriv.h"

#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

png_uint_32 PNGAPI
png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_uint_32 flag)
{ … }

size_t PNGAPI
png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

#ifdef PNG_INFO_IMAGE_SUPPORTED
png_bytepp PNGAPI
png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }
#endif

#ifdef PNG_EASY_ACCESS_SUPPORTED
/* Easy access to info, added in libpng-0.99 */
png_uint_32 PNGAPI
png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_uint_32 PNGAPI
png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_byte PNGAPI
png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_byte PNGAPI
png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_byte PNGAPI
png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_byte PNGAPI
png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_byte PNGAPI
png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_uint_32 PNGAPI
png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
   info_ptr)
{ … }

png_uint_32 PNGAPI
png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
    info_ptr)
{ … }

png_uint_32 PNGAPI
png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

#ifdef PNG_FLOATING_POINT_SUPPORTED
float PNGAPI
png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
   info_ptr)
{ … }
#endif

#ifdef PNG_FIXED_POINT_SUPPORTED
png_fixed_point PNGAPI
png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
    png_const_inforp info_ptr)
{ … }
#endif

png_int_32 PNGAPI
png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_int_32 PNGAPI
png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_int_32 PNGAPI
png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

png_int_32 PNGAPI
png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
static png_uint_32
ppi_from_ppm(png_uint_32 ppm)
{
#if 0
   /* The conversion is *(2.54/100), in binary (32 digits):
    * .00000110100000001001110101001001
    */
   png_uint_32 t1001, t1101;
   ppm >>= 1;                  /* .1 */
   t1001 = ppm + (ppm >> 3);   /* .1001 */
   t1101 = t1001 + (ppm >> 1); /* .1101 */
   ppm >>= 20;                 /* .000000000000000000001 */
   t1101 += t1101 >> 15;       /* .1101000000000001101 */
   t1001 >>= 11;               /* .000000000001001 */
   t1001 += t1001 >> 12;       /* .000000000001001000000001001 */
   ppm += t1001;               /* .000000000001001000001001001 */
   ppm += t1101;               /* .110100000001001110101001001 */
   return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
#else
   /* The argument is a PNG unsigned integer, so it is not permitted
    * to be bigger than 2^31.
    */
   png_fixed_point result;
   if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
       5000) != 0)
      return (png_uint_32)result;

   /* Overflow. */
   return 0;
#endif
}

png_uint_32 PNGAPI
png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
{
   return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
}

png_uint_32 PNGAPI
png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
{
   return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
}

png_uint_32 PNGAPI
png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
{
   return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
}

#ifdef PNG_FIXED_POINT_SUPPORTED
static png_fixed_point
png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
{
   /* Convert from meters * 1,000,000 to inches * 100,000, meters to
    * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
    * Notice that this can overflow - a warning is output and 0 is
    * returned.
    */
   return png_muldiv_warn(png_ptr, microns, 500, 127);
}

png_fixed_point PNGAPI
png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
    png_const_inforp info_ptr)
{
   return png_fixed_inches_from_microns(png_ptr,
       png_get_x_offset_microns(png_ptr, info_ptr));
}
#endif

#ifdef PNG_FIXED_POINT_SUPPORTED
png_fixed_point PNGAPI
png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
    png_const_inforp info_ptr)
{
   return png_fixed_inches_from_microns(png_ptr,
       png_get_y_offset_microns(png_ptr, info_ptr));
}
#endif

#ifdef PNG_FLOATING_POINT_SUPPORTED
float PNGAPI
png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
{
   /* To avoid the overflow do the conversion directly in floating
    * point.
    */
   return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
}
#endif

#ifdef PNG_FLOATING_POINT_SUPPORTED
float PNGAPI
png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
{
   /* To avoid the overflow do the conversion directly in floating
    * point.
    */
   return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
}
#endif

#ifdef PNG_pHYs_SUPPORTED
png_uint_32 PNGAPI
png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
{
   png_uint_32 retval = 0;

   png_debug1(1, "in %s retrieval function", "pHYs");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_pHYs) != 0)
   {
      if (res_x != NULL)
      {
         *res_x = info_ptr->x_pixels_per_unit;
         retval |= PNG_INFO_pHYs;
      }

      if (res_y != NULL)
      {
         *res_y = info_ptr->y_pixels_per_unit;
         retval |= PNG_INFO_pHYs;
      }

      if (unit_type != NULL)
      {
         *unit_type = (int)info_ptr->phys_unit_type;
         retval |= PNG_INFO_pHYs;

         if (*unit_type == 1)
         {
            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
         }
      }
   }

   return retval;
}
#endif /* pHYs */
#endif /* INCH_CONVERSIONS */

/* png_get_channels really belongs in here, too, but it's been around longer */

#endif /* EASY_ACCESS */


png_byte PNGAPI
png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }

#ifdef PNG_READ_SUPPORTED
png_const_bytep PNGAPI
png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
{ … }
#endif

#ifdef PNG_bKGD_SUPPORTED
png_uint_32 PNGAPI
png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
    png_color_16p *background)
{
   png_debug1(1, "in %s retrieval function", "bKGD");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
       background != NULL)
   {
      *background = &(info_ptr->background);
      return PNG_INFO_bKGD;
   }

   return 0;
}
#endif

#ifdef PNG_cHRM_SUPPORTED
/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
 * same time to correct the rgb grayscale coefficient defaults obtained from the
 * cHRM chunk in 1.5.4
 */
#  ifdef PNG_FLOATING_POINT_SUPPORTED
png_uint_32 PNGAPI
png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *white_x, double *white_y, double *red_x, double *red_y,
    double *green_x, double *green_y, double *blue_x, double *blue_y)
{ … }

png_uint_32 PNGAPI
png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *red_X, double *red_Y, double *red_Z, double *green_X,
    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
    double *blue_Z)
{ … }
#  endif

#  ifdef PNG_FIXED_POINT_SUPPORTED
png_uint_32 PNGAPI
png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
    png_fixed_point *int_blue_Z)
{ … }

png_uint_32 PNGAPI
png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
    png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
    png_fixed_point *blue_x, png_fixed_point *blue_y)
{ … }
#  endif
#endif

#ifdef PNG_gAMA_SUPPORTED
#  ifdef PNG_FIXED_POINT_SUPPORTED
png_uint_32 PNGAPI
png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_fixed_point *file_gamma)
{ … }
#  endif

#  ifdef PNG_FLOATING_POINT_SUPPORTED
png_uint_32 PNGAPI
png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *file_gamma)
{ … }
#  endif
#endif

#ifdef PNG_sRGB_SUPPORTED
png_uint_32 PNGAPI
png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
    int *file_srgb_intent)
{ … }
#endif

#ifdef PNG_iCCP_SUPPORTED
png_uint_32 PNGAPI
png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
    png_charpp name, int *compression_type,
    png_bytepp profile, png_uint_32 *proflen)
{ … }
#endif

#ifdef PNG_sPLT_SUPPORTED
int PNGAPI
png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
    png_sPLT_tpp spalettes)
{
   png_debug1(1, "in %s retrieval function", "sPLT");

   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
   {
      *spalettes = info_ptr->splt_palettes;
      return info_ptr->splt_palettes_num;
   }

   return 0;
}
#endif

#ifdef PNG_eXIf_SUPPORTED
png_uint_32 PNGAPI
png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
    png_bytep *exif)
{ … }

png_uint_32 PNGAPI
png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_uint_32 *num_exif, png_bytep *exif)
{ … }
#endif

#ifdef PNG_hIST_SUPPORTED
png_uint_32 PNGAPI
png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
    png_uint_16p *hist)
{
   png_debug1(1, "in %s retrieval function", "hIST");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
   {
      *hist = info_ptr->hist;
      return PNG_INFO_hIST;
   }

   return 0;
}
#endif

png_uint_32 PNGAPI
png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_uint_32 *width, png_uint_32 *height, int *bit_depth,
    int *color_type, int *interlace_type, int *compression_type,
    int *filter_type)
{ … }

#ifdef PNG_oFFs_SUPPORTED
png_uint_32 PNGAPI
png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
{
   png_debug1(1, "in %s retrieval function", "oFFs");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
       offset_x != NULL && offset_y != NULL && unit_type != NULL)
   {
      *offset_x = info_ptr->x_offset;
      *offset_y = info_ptr->y_offset;
      *unit_type = (int)info_ptr->offset_unit_type;
      return PNG_INFO_oFFs;
   }

   return 0;
}
#endif

#ifdef PNG_pCAL_SUPPORTED
png_uint_32 PNGAPI
png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
    png_charp *units, png_charpp *params)
{
   png_debug1(1, "in %s retrieval function", "pCAL");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
       purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
       nparams != NULL && units != NULL && params != NULL)
   {
      *purpose = info_ptr->pcal_purpose;
      *X0 = info_ptr->pcal_X0;
      *X1 = info_ptr->pcal_X1;
      *type = (int)info_ptr->pcal_type;
      *nparams = (int)info_ptr->pcal_nparams;
      *units = info_ptr->pcal_units;
      *params = info_ptr->pcal_params;
      return PNG_INFO_pCAL;
   }

   return 0;
}
#endif

#ifdef PNG_sCAL_SUPPORTED
#  ifdef PNG_FIXED_POINT_SUPPORTED
#    if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
         defined(PNG_FLOATING_POINT_SUPPORTED)
png_uint_32 PNGAPI
png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    int *unit, png_fixed_point *width, png_fixed_point *height)
{
   png_debug1(1, "in %s retrieval function", "sCAL");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_sCAL) != 0)
   {
      *unit = info_ptr->scal_unit;
      /*TODO: make this work without FP support; the API is currently eliminated
       * if neither floating point APIs nor internal floating point arithmetic
       * are enabled.
       */
      *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
      *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
          "sCAL height");
      return PNG_INFO_sCAL;
   }

   return 0;
}
#    endif /* FLOATING_ARITHMETIC */
#  endif /* FIXED_POINT */
#  ifdef PNG_FLOATING_POINT_SUPPORTED
png_uint_32 PNGAPI
png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
    int *unit, double *width, double *height)
{
   png_debug1(1, "in %s retrieval function", "sCAL(float)");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_sCAL) != 0)
   {
      *unit = info_ptr->scal_unit;
      *width = atof(info_ptr->scal_s_width);
      *height = atof(info_ptr->scal_s_height);
      return PNG_INFO_sCAL;
   }

   return 0;
}
#  endif /* FLOATING POINT */
png_uint_32 PNGAPI
png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
    int *unit, png_charpp width, png_charpp height)
{
   png_debug1(1, "in %s retrieval function", "sCAL(str)");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_sCAL) != 0)
   {
      *unit = info_ptr->scal_unit;
      *width = info_ptr->scal_s_width;
      *height = info_ptr->scal_s_height;
      return PNG_INFO_sCAL;
   }

   return 0;
}
#endif /* sCAL */

#ifdef PNG_pHYs_SUPPORTED
png_uint_32 PNGAPI
png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
{
   png_uint_32 retval = 0;

   png_debug1(1, "in %s retrieval function", "pHYs");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_pHYs) != 0)
   {
      if (res_x != NULL)
      {
         *res_x = info_ptr->x_pixels_per_unit;
         retval |= PNG_INFO_pHYs;
      }

      if (res_y != NULL)
      {
         *res_y = info_ptr->y_pixels_per_unit;
         retval |= PNG_INFO_pHYs;
      }

      if (unit_type != NULL)
      {
         *unit_type = (int)info_ptr->phys_unit_type;
         retval |= PNG_INFO_pHYs;
      }
   }

   return retval;
}
#endif /* pHYs */

png_uint_32 PNGAPI
png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
    png_colorp *palette, int *num_palette)
{ … }

#ifdef PNG_sBIT_SUPPORTED
png_uint_32 PNGAPI
png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
    png_color_8p *sig_bit)
{ … }
#endif

#ifdef PNG_TEXT_SUPPORTED
int PNGAPI
png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
    png_textp *text_ptr, int *num_text)
{ … }
#endif

#ifdef PNG_tIME_SUPPORTED
png_uint_32 PNGAPI
png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
    png_timep *mod_time)
{
   png_debug1(1, "in %s retrieval function", "tIME");

   if (png_ptr != NULL && info_ptr != NULL &&
       (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
   {
      *mod_time = &(info_ptr->mod_time);
      return PNG_INFO_tIME;
   }

   return 0;
}
#endif

#ifdef PNG_tRNS_SUPPORTED
png_uint_32 PNGAPI
png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
    png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
{ … }
#endif

#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
int PNGAPI
png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
    png_unknown_chunkpp unknowns)
{ … }
#endif

#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
png_byte PNGAPI
png_get_rgb_to_gray_status(png_const_structrp png_ptr)
{ … }
#endif

#ifdef PNG_USER_CHUNKS_SUPPORTED
png_voidp PNGAPI
png_get_user_chunk_ptr(png_const_structrp png_ptr)
{ … }
#endif

size_t PNGAPI
png_get_compression_buffer_size(png_const_structrp png_ptr)
{ … }

#ifdef PNG_SET_USER_LIMITS_SUPPORTED
/* These functions were added to libpng 1.2.6 and were enabled
 * by default in libpng-1.4.0 */
png_uint_32 PNGAPI
png_get_user_width_max(png_const_structrp png_ptr)
{ … }

png_uint_32 PNGAPI
png_get_user_height_max(png_const_structrp png_ptr)
{ … }

/* This function was added to libpng 1.4.0 */
png_uint_32 PNGAPI
png_get_chunk_cache_max(png_const_structrp png_ptr)
{ … }

/* This function was added to libpng 1.4.1 */
png_alloc_size_t PNGAPI
png_get_chunk_malloc_max(png_const_structrp png_ptr)
{ … }
#endif /* SET_USER_LIMITS */

/* These functions were added to libpng 1.4.0 */
#ifdef PNG_IO_STATE_SUPPORTED
png_uint_32 PNGAPI
png_get_io_state(png_const_structrp png_ptr)
{
   return png_ptr->io_state;
}

png_uint_32 PNGAPI
png_get_io_chunk_type(png_const_structrp png_ptr)
{
   return png_ptr->chunk_name;
}
#endif /* IO_STATE */

#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
int PNGAPI
png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
{
   if (png_ptr != NULL && info_ptr != NULL)
      return png_ptr->num_palette_max;

   return -1;
}
#  endif
#endif

#endif /* READ || WRITE */