www.pudn.com > Image_png.rar > pngget.c

 
/* pngget.c - retrieval of values from info struct 
 * 
 * libpng 1.0.1 
 * For conditions of distribution and use, see copyright notice in png.h 
 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. 
 * Copyright (c) 1996, 1997 Andreas Dilger 
 * Copyright (c) 1998, Glenn Randers-Pehrson 
 * March 15, 1998 
 */ 
 
#define PNG_INTERNAL 
#include "png.h" 
 
png_uint_32 
png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
      return(info_ptr->valid & flag); 
   else 
      return(0); 
} 
 
png_uint_32 
png_get_rowbytes(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
      return(info_ptr->rowbytes); 
   else 
      return(0); 
} 
 
#ifdef PNG_EASY_ACCESS_SUPPORTED 
/* easy access to info, added in libpng-0.99 */ 
png_uint_32 
png_get_image_width(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->width; 
   } 
   return (0); 
} 
 
png_uint_32 
png_get_image_height(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->height; 
   } 
   return (0); 
} 
 
png_byte 
png_get_bit_depth(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->bit_depth; 
   } 
   return (0); 
} 
 
png_byte 
png_get_color_type(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->color_type; 
   } 
   return (0); 
} 
 
png_byte 
png_get_filter_type(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->filter_type; 
   } 
   return (0); 
} 
 
png_byte 
png_get_interlace_type(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->interlace_type; 
   } 
   return (0); 
} 
 
png_byte 
png_get_compression_type(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
   { 
      return info_ptr->compression_type; 
   } 
   return (0); 
} 
 
png_uint_32 
png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter"); 
      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER) 
          return (0); 
      else return (info_ptr->x_pixels_per_unit); 
   } 
   else 
#endif 
   return (0); 
} 
 
png_uint_32 
png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter"); 
      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER) 
          return (0); 
      else return (info_ptr->y_pixels_per_unit); 
   } 
   else 
#endif 
   return (0); 
} 
 
png_uint_32 
png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "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 (0); 
      else return (info_ptr->x_pixels_per_unit); 
   } 
   else 
#endif 
   return (0); 
} 
 
float 
png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr) 
   { 
#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio"); 
      if (info_ptr->x_pixels_per_unit == 0) 
         return ((float)0.0); 
      else 
         return ((float)info_ptr->y_pixels_per_unit 
            /(float)info_ptr->x_pixels_per_unit); 
   } 
   else 
#endif 
      return ((float)0.0); 
} 
 
png_uint_32 
png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns"); 
      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER) 
          return (0); 
      else return (info_ptr->x_offset); 
   } 
   else 
#endif 
   return (0); 
} 
 
png_uint_32 
png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns"); 
      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER) 
          return (0); 
      else return (info_ptr->y_offset); 
   } 
   else 
#endif 
   return (0); 
} 
 
png_uint_32 
png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns"); 
      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL) 
          return (0); 
      else return (info_ptr->x_offset); 
   } 
   else 
#endif 
   return (0); 
} 
 
png_uint_32 
png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr) 
{ 
#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns"); 
      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL) 
          return (0); 
      else return (info_ptr->y_offset); 
   } 
   else 
#endif 
   return (0); 
} 
 
#ifdef PNG_INCH_CONVERSIONS 
png_uint_32 
png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) 
{ 
   return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr) 
     *.03937 +.5) 
} 
 
png_uint_32 
png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) 
{ 
   return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr) 
     *.03937 +.5) 
} 
 
png_uint_32 
png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) 
{ 
   return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr) 
     *.03937 +.5) 
} 
 
float 
png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr) 
{ 
   return ((float)png_get_x_offset_microns(png_ptr, info_ptr) 
     *.03937/1000000. +.5) 
} 
 
float 
png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr) 
{ 
   return ((float)png_get_y_offset_microns(png_ptr, info_ptr) 
     *.03937/1000000. +.5) 
} 
 
#if defined(PNG_READ_pHYs_SUPPORTED) 
png_uint_32 
png_get_pHYs_dpi(png_structp png_ptr, png_infop 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\n", "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 * 39.37 + .50); 
            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50); 
         } 
      } 
   } 
   return (retval); 
} 
#endif 
 
#endif  /* PNG_INCH_CONVERSIONS */ 
 
/* png_get_channels really belongs in here, too, but it's been around longer */ 
#endif  /* PNG_EASY_ACCESS_SUPPORTED */ 
 
png_byte 
png_get_channels(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
      return(info_ptr->channels); 
   else 
      return (0); 
} 
 
png_bytep 
png_get_signature(png_structp png_ptr, png_infop info_ptr) 
{ 
   if (png_ptr != NULL && info_ptr != NULL) 
      return(info_ptr->signature); 
   else 
      return (NULL); 
} 
 
#if defined(PNG_READ_bKGD_SUPPORTED) 
png_uint_32 
png_get_bKGD(png_structp png_ptr, png_infop 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\n", "bKGD"); 
      *background = &(info_ptr->background); 
      return (PNG_INFO_bKGD); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_cHRM_SUPPORTED) 
png_uint_32 
png_get_cHRM(png_structp png_ptr, png_infop 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) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) 
   { 
      png_debug1(1, "in %s retrieval function\n", "cHRM"); 
      if (white_x != NULL) 
         *white_x = (double)info_ptr->x_white; 
      if (white_y != NULL) 
         *white_y = (double)info_ptr->y_white; 
      if (red_x != NULL) 
         *red_x = (double)info_ptr->x_red; 
      if (red_y != NULL) 
         *red_y = (double)info_ptr->y_red; 
      if (green_x != NULL) 
         *green_x = (double)info_ptr->x_green; 
      if (green_y != NULL) 
         *green_y = (double)info_ptr->y_green; 
      if (blue_x != NULL) 
         *blue_x = (double)info_ptr->x_blue; 
      if (blue_y != NULL) 
         *blue_y = (double)info_ptr->y_blue; 
      return (PNG_INFO_cHRM); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_gAMA_SUPPORTED) 
png_uint_32 
png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) 
      && file_gamma != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "gAMA"); 
      *file_gamma = (double)info_ptr->gamma; 
      return (PNG_INFO_gAMA); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_sRGB_SUPPORTED) 
png_uint_32 
png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB) 
      && file_srgb_intent != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "sRGB"); 
      *file_srgb_intent = (int)info_ptr->srgb_intent; 
      return (PNG_INFO_sRGB); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_hIST_SUPPORTED) 
png_uint_32 
png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) 
      && hist != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "hIST"); 
      *hist = info_ptr->hist; 
      return (PNG_INFO_hIST); 
   } 
   return (0); 
} 
#endif 
 
png_uint_32 
png_get_IHDR(png_structp png_ptr, png_infop 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) 
    
{ 
   if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL && 
      bit_depth != NULL && color_type != NULL) 
   { 
      int pixel_depth, channels; 
      png_uint_32 rowbytes_per_pixel; 
 
      png_debug1(1, "in %s retrieval function\n", "IHDR"); 
      *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; 
 
      /* check for potential overflow of rowbytes */ 
      if (*color_type == PNG_COLOR_TYPE_PALETTE) 
         channels = 1; 
      else if (*color_type & PNG_COLOR_MASK_COLOR) 
         channels = 3; 
      else 
         channels = 1; 
      if (*color_type & PNG_COLOR_MASK_ALPHA) 
         channels++; 
      pixel_depth = *bit_depth * channels; 
      rowbytes_per_pixel = (pixel_depth + 7) >> 3; 
      if ((*width > (png_uint_32)2147483647L/rowbytes_per_pixel)) 
      { 
         png_warning(png_ptr, 
            "Width too large for libpng to process image data."); 
      } 
      return (1); 
   } 
   return (0); 
} 
 
#if defined(PNG_READ_oFFs_SUPPORTED) 
png_uint_32 
png_get_oFFs(png_structp png_ptr, png_infop info_ptr, 
   png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) 
      && offset_x != NULL && offset_y != NULL && unit_type != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "oFFs"); 
      *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 
 
#if defined(PNG_READ_pCAL_SUPPORTED) 
png_uint_32 
png_get_pCAL(png_structp png_ptr, png_infop info_ptr, 
   png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, 
   png_charp *units, png_charpp *params) 
{ 
   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) 
   { 
      png_debug1(1, "in %s retrieval function\n", "pCAL"); 
      *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 
 
#if defined(PNG_READ_pHYs_SUPPORTED) 
png_uint_32 
png_get_pHYs(png_structp png_ptr, png_infop 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\n", "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 
 
png_uint_32 
png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette, 
   int *num_palette) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE && 
       palette != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "PLTE"); 
      *palette = info_ptr->palette; 
      *num_palette = info_ptr->num_palette; 
      png_debug1(3, "num_palette = %d\n", *num_palette); 
      return (PNG_INFO_PLTE); 
   } 
   return (0); 
} 
 
#if defined(PNG_READ_sBIT_SUPPORTED) 
png_uint_32 
png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT && 
       sig_bit != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "sBIT"); 
      *sig_bit = &(info_ptr->sig_bit); 
      return (PNG_INFO_sBIT); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) 
png_uint_32 
png_get_text(png_structp png_ptr, png_infop 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 %s retrieval function\n", 
         (png_ptr->chunk_name[0] == '\0' ? "text" 
             : (png_const_charp)png_ptr->chunk_name)); 
      if (text_ptr != NULL) 
         *text_ptr = info_ptr->text; 
      if (num_text != NULL) 
         *num_text = info_ptr->num_text; 
      return ((png_uint_32)info_ptr->num_text); 
   } 
   return(0); 
} 
#endif 
 
#if defined(PNG_READ_tIME_SUPPORTED) 
png_uint_32 
png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time) 
{ 
   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME && 
       mod_time != NULL) 
   { 
      png_debug1(1, "in %s retrieval function\n", "tIME"); 
      *mod_time = &(info_ptr->mod_time); 
      return (PNG_INFO_tIME); 
   } 
   return (0); 
} 
#endif 
 
#if defined(PNG_READ_tRNS_SUPPORTED) 
png_uint_32 
png_get_tRNS(png_structp png_ptr, png_infop info_ptr, 
   png_bytep *trans, int *num_trans, png_color_16p *trans_values) 
{ 
   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\n", "tRNS"); 
      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) 
      { 
          if (trans != NULL) 
          { 
             *trans = info_ptr->trans; 
             retval |= PNG_INFO_tRNS; 
          } 
          if (trans_values != NULL) 
             *trans_values = &(info_ptr->trans_values); 
      } 
      else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ 
      { 
          if (trans_values != NULL) 
          { 
             *trans_values = &(info_ptr->trans_values); 
             retval |= PNG_INFO_tRNS; 
          } 
          if(trans != NULL) 
             *trans = NULL; 
      } 
      if(num_trans != NULL) 
      { 
         *num_trans = info_ptr->num_trans; 
         retval |= PNG_INFO_tRNS; 
      } 
   } 
   return (retval); 
} 
#endif