    /* 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 */