text: /* pngget.c - retrieval of values from info struct
   *
   * Last changed in libpng 1.6.1 [March 28, 2013]
   * Copyright (c) 1998-2013 Glenn Randers-Pehrson
   * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   * (Version 0.88 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)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return(info_ptr->valid & flag);
  
     return(0);
  }
  
  png_size_t PNGAPI
  png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return(info_ptr->rowbytes);
  
     return(0);
  }
  
  #ifdef PNG_INFO_IMAGE_SUPPORTED
  png_bytepp PNGAPI
  png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return(info_ptr->row_pointers);
  
     return(0);
  }
  #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)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->width;
  
     return (0);
  }
  
  png_uint_32 PNGAPI
  png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->height;
  
     return (0);
  }
  
  png_byte PNGAPI
  png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->bit_depth;
  
     return (0);
  }
  
  png_byte PNGAPI
  png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->color_type;
  
     return (0);
  }
  
  png_byte PNGAPI
  png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->filter_type;
  
     return (0);
  }
  
  png_byte PNGAPI
  png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->interlace_type;
  
     return (0);
  }
  
  png_byte PNGAPI
  png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return info_ptr->compression_type;
  
     return (0);
  }
  
  png_uint_32 PNGAPI
  png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
     info_ptr)
  {
  #ifdef PNG_pHYs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
        {
           png_debug1(1, "in %s retrieval function",
               "png_get_x_pixels_per_meter");
  
           if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
              return (info_ptr->x_pixels_per_unit);
        }
  #endif
  
     return (0);
  }
  
  png_uint_32 PNGAPI
  png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
      info_ptr)
  {
  #ifdef PNG_pHYs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
     {
        png_debug1(1, "in %s retrieval function",
            "png_get_y_pixels_per_meter");
  
        if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
           return (info_ptr->y_pixels_per_unit);
     }
  #endif
  
     return (0);
  }
  
  png_uint_32 PNGAPI
  png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
  #ifdef PNG_pHYs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
  
        if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
            info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
           return (info_ptr->x_pixels_per_unit);
     }
  #endif
  
     return (0);
  }
  
  #ifdef PNG_FLOATING_POINT_SUPPORTED
  float PNGAPI
  png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
     info_ptr)
  {
  #ifdef PNG_READ_pHYs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
  
        if (info_ptr->x_pixels_per_unit != 0)
           return ((float)((float)info_ptr->y_pixels_per_unit
               /(float)info_ptr->x_pixels_per_unit));
     }
  #else
     PNG_UNUSED(png_ptr)
     PNG_UNUSED(info_ptr)
  #endif
  
     return ((float)0.0);
  }
  #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)
  {
  #ifdef PNG_READ_pHYs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
         && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
         && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
         && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
     {
        png_fixed_point res;
  
        png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
  
        /* The following casts work because a PNG 4 byte integer only has a valid
         * range of 0..2^31-1; otherwise the cast might overflow.
         */
        if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
            (png_int_32)info_ptr->x_pixels_per_unit))
           return res;
     }
  #else
     PNG_UNUSED(png_ptr)
     PNG_UNUSED(info_ptr)
  #endif
  
     return 0;
  }
  #endif
  
  png_int_32 PNGAPI
  png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
  #ifdef PNG_oFFs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
  
        if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
           return (info_ptr->x_offset);
     }
  #endif
  
     return (0);
  }
  
  png_int_32 PNGAPI
  png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
  #ifdef PNG_oFFs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
  
        if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
           return (info_ptr->y_offset);
     }
  #endif
  
     return (0);
  }
  
  png_int_32 PNGAPI
  png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
  #ifdef PNG_oFFs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
  
        if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
           return (info_ptr->x_offset);
     }
  #endif
  
     return (0);
  }
  
  png_int_32 PNGAPI
  png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
  #ifdef PNG_oFFs_SUPPORTED
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
     {
        png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
  
        if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
           return (info_ptr->y_offset);
     }
  #endif
  
     return (0);
  }
  
  #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))
        return 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 metres * 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;
  
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
     {
        png_debug1(1, "in %s retrieval function", "pHYs");
  
        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 /* PNG_pHYs_SUPPORTED */
  #endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
  
  /* png_get_channels really belongs in here, too, but it's been around longer */
  
  #endif  /* PNG_EASY_ACCESS_SUPPORTED */
  
  
  png_byte PNGAPI
  png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return(info_ptr->channels);
  
     return (0);
  }
  
  #ifdef PNG_READ_SUPPORTED
  png_const_bytep PNGAPI
  png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
  {
     if (png_ptr != NULL && info_ptr != NULL)
        return(info_ptr->signature);
  
     return (NULL);
  }
  #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)
  {
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
         && background != NULL)
     {
        png_debug1(1, "in %s retrieval function", "bKGD");
  
        *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)
  {
     /* Quiet API change: this code used to only return the end points if a cHRM
      * chunk was present, but the end points can also come from iCCP or sRGB
      * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
      * the png_set_ APIs merely check that set end points are mutually
      * consistent.
      */
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
     {
        png_debug1(1, "in %s retrieval function", "cHRM");
  
        if (white_x != NULL)
           *white_x = png_float(png_ptr,
              info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
        if (white_y != NULL)
           *white_y = png_float(png_ptr,
              info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
        if (red_x != NULL)
           *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
              "cHRM red X");
        if (red_y != NULL)
           *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
              "cHRM red Y");
        if (green_x != NULL)
           *green_x = png_float(png_ptr,
              info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
        if (green_y != NULL)
           *green_y = png_float(png_ptr,
              info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
        if (blue_x != NULL)
           *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
              "cHRM blue X");
        if (blue_y != NULL)
           *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
              "cHRM blue Y");
        return (PNG_INFO_cHRM);
     }
  
     return (0);
  }
  
  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)
  {
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
     {
        png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
  
        if (red_X != NULL)
           *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
              "cHRM red X");
        if (red_Y != NULL)
           *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
              "cHRM red Y");
        if (red_Z != NULL)
           *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
              "cHRM red Z");
        if (green_X != NULL)
           *green_X = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
        if (green_Y != NULL)
           *green_Y = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
        if (green_Z != NULL)
           *green_Z = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
        if (blue_X != NULL)
           *blue_X = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
        if (blue_Y != NULL)
           *blue_Y = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
        if (blue_Z != NULL)
           *blue_Z = png_float(png_ptr,
              info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
        return (PNG_INFO_cHRM);
     }
  
     return (0);
  }
  #  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)
  {
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
     {
        png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
  
        if (int_red_X != NULL)
           *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
        if (int_red_Y != NULL)
           *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
        if (int_red_Z != NULL)
           *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
        if (int_green_X != NULL)
           *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
        if (int_green_Y != NULL)
           *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
        if (int_green_Z != NULL)
           *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
        if (int_blue_X != NULL)
           *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
        if (int_blue_Y != NULL)
           *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
        if (int_blue_Z != NULL)
           *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
        return (PNG_INFO_cHRM);
     }
  
     return (0);
  }
  
  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)
  {
     png_debug1(1, "in %s retrieval function", "cHRM");
  
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
     {
        if (white_x != NULL)
           *white_x = info_ptr->colorspace.end_points_xy.whitex;
        if (white_y != NULL)
           *white_y = info_ptr->colorspace.end_points_xy.whitey;
        if (red_x != NULL)
           *red_x = info_ptr->colorspace.end_points_xy.redx;
        if (red_y != NULL)
           *red_y = info_ptr->colorspace.end_points_xy.redy;
        if (green_x != NULL)
           *green_x = info_ptr->colorspace.end_points_xy.greenx;
        if (green_y != NULL)
           *green_y = info_ptr->colorspace.end_points_xy.greeny;
        if (blue_x != NULL)
           *blue_x = info_ptr->colorspace.end_points_xy.bluex;
        if (blue_y != NULL)
           *blue_y = info_ptr->colorspace.end_points_xy.bluey;
        return (PNG_INFO_cHRM);
     }
  
     return (0);
  }
  #  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)
  {
     png_debug1(1, "in %s retrieval function", "gAMA");
  
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
        file_gamma != NULL)
     {
        *file_gamma = info_ptr->colorspace.gamma;
        return (PNG_INFO_gAMA);
     }
  
     return (0);
  }
  #  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)
  {
     png_debug1(1, "in %s retrieval function", "gAMA(float)");
  
     if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
        file_gamma != NULL)
     {
        *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
           "png_get_gAMA");
        return (PNG_INFO_gAMA);
     }
  
     return (0);
  }
  #  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)
  {
     png_debug1(1, "in %s retrieval function", "sRGB");
  
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
         && file_srgb_intent != NULL)
     {
        *file_srgb_intent = info_ptr->colorspace.rendering_intent;
        return (PNG_INFO_sRGB);
     }
  
     return (0);
  }
  #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)
  {
     png_debug1(1, "in %s retrieval function", "iCCP");
  
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
         && name != NULL && compression_type != NULL && profile != NULL &&
  		 proflen != NULL)
     {
        *name = info_ptr->iccp_name;
        *profile = info_ptr->iccp_profile;
        *proflen = png_get_uint_32(info_ptr->iccp_profile);
        /* This is somewhat irrelevant since the profile data returned has
         * actually been uncompressed.
         */
        *compression_type = PNG_COMPRESSION_TYPE_BASE;
        return (PNG_INFO_iCCP);
     }
  
     return (0);
  }
  #endif
  
  #ifdef PNG_sPLT_SUPPORTED
  int PNGAPI
  png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
      png_sPLT_tpp spalettes)
  {
     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_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)
         && 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)
  {
     png_debug1(1, "in %s retrieval function", "IHDR");
  
     if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
         height == NULL || bit_depth == NULL || color_type == NULL)
        return (0);
  
     *width = info_ptr->width;
     *height = info_ptr->height;
     *bit_depth = info_ptr->bit_depth;
     *color_type = info_ptr->color_type;
  
     if (compression_type != NULL)
        *compression_type = info_ptr->compression_type;
  
     if (filter_type != NULL)
        *filter_type = info_ptr->filter_type;
  
     if (interlace_type != NULL)
        *interlace_type = info_ptr->interlace_type;
  
     /* This is redundant if we can be sure that the info_ptr values were all
      * assigned in png_set_IHDR().  We do the check anyhow in case an
      * application has ignored our advice not to mess with the members
      * of info_ptr directly.
      */
     png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
         info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
         info_ptr->compression_type, info_ptr->filter_type);
  
     return (1);
  }
  
  #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)
         && 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)
         && 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)
  {
     if (png_ptr != NULL && info_ptr != NULL &&
         (info_ptr->valid & PNG_INFO_sCAL))
     {
        *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)
  {
     if (png_ptr != NULL && info_ptr != NULL &&
         (info_ptr->valid & PNG_INFO_sCAL))
     {
        *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)
  {
     if (png_ptr != NULL && info_ptr != NULL &&
         (info_ptr->valid & PNG_INFO_sCAL))
     {
        *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))
     {
        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)
  {
     png_debug1(1, "in %s retrieval function", "PLTE");
  
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
         && palette != NULL)
     {
        *palette = info_ptr->palette;
        *num_palette = info_ptr->num_palette;
        png_debug1(3, "num_palette = %d", *num_palette);
        return (PNG_INFO_PLTE);
     }
  
     return (0);
  }
  
  #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)
  {
     png_debug1(1, "in %s retrieval function", "sBIT");
  
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
         && sig_bit != NULL)
     {
        *sig_bit = &(info_ptr->sig_bit);
        return (PNG_INFO_sBIT);
     }
  
     return (0);
  }
  #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)
  {
     if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
     {
        png_debug1(1, "in 0x%lx retrieval function",
           (unsigned long)png_ptr->chunk_name);
  
        if (text_ptr != NULL)
           *text_ptr = info_ptr->text;
  
        if (num_text != NULL)
           *num_text = info_ptr->num_text;
  
        return info_ptr->num_text;
     }
  
     if (num_text != NULL)
        *num_text = 0;
  
     return(0);
  }
  #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)
         && 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)
  {
     png_uint_32 retval = 0;
     if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
     {
        png_debug1(1, "in %s retrieval function", "tRNS");
  
        if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
        {
           if (trans_alpha != NULL)
           {
              *trans_alpha = info_ptr->trans_alpha;
              retval |= PNG_INFO_tRNS;
           }
  
           if (trans_color != NULL)
              *trans_color = &(info_ptr->trans_color);
        }
  
        else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
        {
           if (trans_color != NULL)
           {
              *trans_color = &(info_ptr->trans_color);
              retval |= PNG_INFO_tRNS;
           }
  
           if (trans_alpha != NULL)
              *trans_alpha = NULL;
        }
  
        if (num_trans != NULL)
        {
           *num_trans = info_ptr->num_trans;
           retval |= PNG_INFO_tRNS;
        }
     }
  
     return (retval);
  }
  #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)
  {
     if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
     {
        *unknowns = info_ptr->unknown_chunks;
        return info_ptr->unknown_chunks_num;
     }
  
     return (0);
  }
  #endif
  
  #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  png_byte PNGAPI
  png_get_rgb_to_gray_status (png_const_structrp png_ptr)
  {
     return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
  }
  #endif
  
  #ifdef PNG_USER_CHUNKS_SUPPORTED
  png_voidp PNGAPI
  png_get_user_chunk_ptr(png_const_structrp png_ptr)
  {
     return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
  }
  #endif
  
  png_size_t PNGAPI
  png_get_compression_buffer_size(png_const_structrp png_ptr)
  {
     if (png_ptr == NULL)
        return 0;
  
  #  ifdef PNG_WRITE_SUPPORTED
        if (png_ptr->mode & PNG_IS_READ_STRUCT)
  #  endif
     {
  #     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
           return png_ptr->IDAT_read_size;
  #     else
           return PNG_IDAT_READ_SIZE;
  #     endif
     }
  
  #  ifdef PNG_WRITE_SUPPORTED
        else
           return png_ptr->zbuffer_size;
  #  endif
  }
  
  #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)
  {
     return (png_ptr ? png_ptr->user_width_max : 0);
  }
  
  png_uint_32 PNGAPI
  png_get_user_height_max (png_const_structrp png_ptr)
  {
     return (png_ptr ? png_ptr->user_height_max : 0);
  }
  
  /* This function was added to libpng 1.4.0 */
  png_uint_32 PNGAPI
  png_get_chunk_cache_max (png_const_structrp png_ptr)
  {
     return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
  }
  
  /* This function was added to libpng 1.4.1 */
  png_alloc_size_t PNGAPI
  png_get_chunk_malloc_max (png_const_structrp png_ptr)
  {
     return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
  }
  #endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
  
  /* 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 /* ?PNG_IO_STATE_SUPPORTED */
  
  #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 /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
  