hwrf-baseline-20120103-1354/ungrib/src/ngl/g2/enc_png.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #ifdef USE_PNG
   5 #include <png.h>
   6 #include <zlib.h>
   7 #endif /* USE_PNG */
   8
   9 #ifdef __64BIT__
  10   typedef int g2int;
  11 #else
  12   typedef long g2int;
  13 #endif
  14
  15 #if defined _UNDERSCORE
  16    #define enc_png enc_png_
  17 #elif defined _DOUBLEUNDERSCORE
  18    #define enc_png enc_png__
  19 #endif
  20
  21 #ifdef USE_PNG
  22 struct png_stream {
  23    unsigned char *stream_ptr;     /*  location to write PNG stream  */
  24    g2int stream_len;               /*  number of bytes written       */
  25 };
  26 typedef struct png_stream png_stream;
  27
  28 void user_write_data(png_structp ,png_bytep , png_uint_32 );
  29 void user_flush_data(png_structp );
  30
  31 void user_write_data(png_structp png_ptr,png_bytep data, png_uint_32 length)
  32 /*
  33         Custom write function used to that libpng will write
  34         to memory location instead of a file on disk
  35 */
  36 {
  37      unsigned char *ptr;
  38      g2int offset;
  39      png_stream *mem;
  40
  41      mem=(png_stream *)png_get_io_ptr(png_ptr);
  42      ptr=mem->stream_ptr;
  43      offset=mem->stream_len;
  44 /*     printf("SAGwr %ld %ld %x\n",offset,length,ptr);    */
  45      /*for (j=offset,k=0;k<length;j++,k++) ptr[j]=data[k];*/
  46      memcpy(ptr+offset,data,length);
  47      mem->stream_len += length;
  48 }
  49
  50
  51 void user_flush_data(png_structp png_ptr)
  52 /*
  53         Dummy Custom flush function
  54 */
  55 {
  56    int *do_nothing=NULL;
  57 }
  58 #endif /* USE_PNG */
  59
  60
  61 int enc_png(char *data,g2int *width,g2int *height,g2int *nbits,char *pngbuf)
  62 {
  63     g2int pnglen;
  64 #ifdef USE_PNG
  65     int color_type;
  66     g2int j,bytes,bit_depth;
  67     png_structp png_ptr;
  68     png_infop info_ptr;
  69 /*    png_bytep *row_pointers[*height]; */
  70     png_bytep **row_pointers;
  71     png_stream write_io_ptr;
  72
  73 /* create and initialize png_structs  */
  74
  75     png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
  76                                       NULL, NULL);
  77     if (!png_ptr)
  78        return (-1);
  79
  80     info_ptr = png_create_info_struct(png_ptr);
  81     if (!info_ptr)
  82     {
  83        png_destroy_write_struct(&png_ptr,(png_infopp)NULL);
  84        return (-2);
  85     }
  86
  87 /*     Set Error callback   */
  88
  89     if (setjmp(png_jmpbuf(png_ptr)))
  90     {
  91        png_destroy_write_struct(&png_ptr, &info_ptr);
  92        return (-3);
  93     }
  94
  95 /*    Initialize info for writing PNG stream to memory   */
  96
  97     write_io_ptr.stream_ptr=(png_voidp)pngbuf;
  98     write_io_ptr.stream_len=0;
  99
 100 /*    Set new custom write functions    */
 101
 102     png_set_write_fn(png_ptr,(voidp)&write_io_ptr,(png_rw_ptr)user_write_data,
 103                     (png_flush_ptr)user_flush_data);
 104 /*    png_init_io(png_ptr, fptr);   */
 105 /*    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);  */
 106
 107 /*     Set the image size, colortype, filter type, etc...      */
 108
 109 /*    printf("SAGTsettingIHDR %d %d %d\n",*width,*height,bit_depth); */
 110     bit_depth=*nbits;
 111     color_type=PNG_COLOR_TYPE_GRAY;
 112     if (*nbits == 24 ) {
 113         bit_depth=8;
 114         color_type=PNG_COLOR_TYPE_RGB;
 115     }
 116     else if (*nbits == 32 ) {
 117         bit_depth=8;
 118         color_type=PNG_COLOR_TYPE_RGB_ALPHA;
 119     }
 120     png_set_IHDR(png_ptr, info_ptr, *width, *height,
 121        bit_depth, color_type, PNG_INTERLACE_NONE,
 122        PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 123
 124 /*     Put image data into the PNG info structure    */
 125
 126     /*bytes=bit_depth/8;*/
 127     bytes=*nbits/8;
 128     row_pointers=malloc((*height)*sizeof(png_bytep));
 129     for (j=0;j<*height;j++) row_pointers[j]=(png_bytep *)(data+(j*(*width)*bytes));
 130     png_set_rows(png_ptr, info_ptr, (png_bytepp)row_pointers);
 131
 132 /*     Do the PNG encoding, and write out PNG stream  */
 133
 134     png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
 135
 136 /*     Clean up   */
 137
 138     png_destroy_write_struct(&png_ptr, &info_ptr);
 139     free(row_pointers);
 140     pnglen=write_io_ptr.stream_len;
 141 #endif /* USE_PNG */
 142     return pnglen;
 143
 144 }
 145