gp2x/readpng.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <png.h>
   4 #include "readpng.h"
   5
   6 void readpng(void *dest, const char *fname, readpng_what what)
   7 {
   8         FILE *fp;
   9         png_structp png_ptr = NULL;
  10         png_infop info_ptr = NULL;
  11         png_bytepp row_ptr = NULL;
  12
  13         if (dest == NULL || fname == NULL)
  14         {
  15                 return;
  16         }
  17
  18         fp = fopen(fname, "rb");
  19         if (fp == NULL)
  20         {
  21                 printf(__FILE__ ": failed to open: %s\n", fname);
  22                 return;
  23         }
  24
  25         png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  26         if (!png_ptr)
  27         {
  28                 printf(__FILE__ ": png_create_read_struct() failed\n");
  29                 fclose(fp);
  30                 return;
  31         }
  32
  33         info_ptr = png_create_info_struct(png_ptr);
  34         if (!info_ptr)
  35         {
  36                 printf(__FILE__ ": png_create_info_struct() failed\n");
  37                 goto done;
  38         }
  39
  40         // Start reading
  41         png_init_io(png_ptr, fp);
  42         png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_PACKING, NULL);
  43         row_ptr = png_get_rows(png_ptr, info_ptr);
  44         if (row_ptr == NULL)
  45         {
  46                 printf(__FILE__ ": png_get_rows() failed\n");
  47                 goto done;
  48         }
  49
  50         // printf("%s: %ix%i @ %ibpp\n", fname, (int)info_ptr->width, (int)info_ptr->height, info_ptr->pixel_depth);
  51
  52         switch (what)
  53         {
  54                 case READPNG_BG:
  55                 {
  56                         int height, width, h;
  57                         unsigned short *dst = dest;
  58                         if (info_ptr->pixel_depth != 24)
  59                         {
  60                                 printf(__FILE__ ": bg image uses %ibpp, needed 24bpp\n", info_ptr->pixel_depth);
  61                                 break;
  62                         }
  63                         height = info_ptr->height;
  64                         if (height > 240) height = 240;
  65                         width = info_ptr->width;
  66                         if (width > 320) width = 320;
  67
  68                         for (h = 0; h < height; h++)
  69                         {
  70                                 unsigned char *src = row_ptr[h];
  71                                 int len = width;
  72                                 while (len--)
  73                                 {
  74                                         *dst++ = ((src[0]&0xf8)<<8) | ((src[1]&0xf8)<<3) | (src[2] >> 3);
  75                                         src += 3;
  76                                 }
  77                                 dst += 320 - width;
  78                         }
  79                         break;
  80                 }
  81
  82                 case READPNG_FONT:
  83                 {
  84                         int x, y, x1, y1;
  85                         unsigned char *dst = dest;
  86                         if (info_ptr->width != 128 || info_ptr->height != 160)
  87                         {
  88                                 printf(__FILE__ ": unexpected font image size %ix%i, needed 128x160\n",
  89                                         (int)info_ptr->width, (int)info_ptr->height);
  90                                 break;
  91                         }
  92                         if (info_ptr->pixel_depth != 8)
  93                         {
  94                                 printf(__FILE__ ": font image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
  95                                 break;
  96                         }
  97                         for (y = 0; y < 16; y++)
  98                         {
  99                                 for (x = 0; x < 16; x++)
 100                                 {
 101                                         for (y1 = 0; y1 < 10; y1++)
 102                                         {
 103                                                 unsigned char *src = row_ptr[y*10 + y1] + x*8;
 104                                                 for (x1 = 8/2; x1 > 0; x1--, src+=2)
 105                                                         *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
 106                                         }
 107                                 }
 108                         }
 109                         break;
 110                 }
 111
 112                 case READPNG_SELECTOR:
 113                 {
 114                         int x1, y1;
 115                         unsigned char *dst = dest;
 116                         if (info_ptr->width != 8 || info_ptr->height != 10)
 117                         {
 118                                 printf(__FILE__ ": unexpected selector image size %ix%i, needed 8x10\n",
 119                                         (int)info_ptr->width, (int)info_ptr->height);
 120                                 break;
 121                         }
 122                         if (info_ptr->pixel_depth != 8)
 123                         {
 124                                 printf(__FILE__ ": selector image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
 125                                 break;
 126                         }
 127                         for (y1 = 0; y1 < 10; y1++)
 128                         {
 129                                 unsigned char *src = row_ptr[y1];
 130                                 for (x1 = 8/2; x1 > 0; x1--, src+=2)
 131                                         *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
 132                         }
 133                         break;
 134                 }
 135         }
 136
 137
 138 done:
 139         png_destroy_read_struct(&png_ptr, info_ptr ? &info_ptr : NULL, (png_infopp)NULL);
 140         fclose(fp);
 141 }
 142
 143