frontend/common/readpng.c

   1 /*
   2  * (C) Gražvydas "notaz" Ignotas, 2008-2010
   3  *
   4  * This work is licensed under the terms of any of these licenses
   5  * (at your option):
   6  *  - GNU GPL, version 2 or later.
   7  *  - GNU LGPL, version 2.1 or later.
   8  * See the COPYING file in the top-level directory.
   9  */
  10
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <png.h>
  14 #include "readpng.h"
  15 #include "lprintf.h"
  16
  17 int readpng(void *dest, const char *fname, readpng_what what, int req_w, int req_h)
  18 {
  19         FILE *fp;
  20         png_structp png_ptr = NULL;
  21         png_infop info_ptr = NULL;
  22         png_bytepp row_ptr = NULL;
  23         int ret = -1;
  24
  25         if (dest == NULL || fname == NULL)
  26         {
  27                 return -1;
  28         }
  29
  30         fp = fopen(fname, "rb");
  31         if (fp == NULL)
  32         {
  33                 lprintf(__FILE__ ": failed to open: %s\n", fname);
  34                 return -1;
  35         }
  36
  37         png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  38         if (!png_ptr)
  39         {
  40                 lprintf(__FILE__ ": png_create_read_struct() failed\n");
  41                 fclose(fp);
  42                 return -1;
  43         }
  44
  45         info_ptr = png_create_info_struct(png_ptr);
  46         if (!info_ptr)
  47         {
  48                 lprintf(__FILE__ ": png_create_info_struct() failed\n");
  49                 goto done;
  50         }
  51
  52         // Start reading
  53         png_init_io(png_ptr, fp);
  54         png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_PACKING, NULL);
  55         row_ptr = png_get_rows(png_ptr, info_ptr);
  56         if (row_ptr == NULL)
  57         {
  58                 lprintf(__FILE__ ": png_get_rows() failed\n");
  59                 goto done;
  60         }
  61
  62         // lprintf("%s: %ix%i @ %ibpp\n", fname, (int)info_ptr->width, (int)info_ptr->height, info_ptr->pixel_depth);
  63
  64         switch (what)
  65         {
  66                 case READPNG_BG:
  67                 {
  68                         int height, width, h;
  69                         unsigned short *dst = dest;
  70                         if (info_ptr->pixel_depth != 24)
  71                         {
  72                                 lprintf(__FILE__ ": bg image uses %ibpp, needed 24bpp\n", info_ptr->pixel_depth);
  73                                 break;
  74                         }
  75                         height = info_ptr->height;
  76                         if (height > req_h)
  77                                 height = req_h;
  78                         width = info_ptr->width;
  79                         if (width > req_w)
  80                                 width = req_w;
  81
  82                         for (h = 0; h < height; h++)
  83                         {
  84                                 unsigned char *src = row_ptr[h];
  85                                 int len = width;
  86                                 while (len--)
  87                                 {
  88 #ifdef PSP
  89                                         *dst++ = ((src[2]&0xf8)<<8) | ((src[1]&0xf8)<<3) | (src[0] >> 3); // BGR
  90 #else
  91                                         *dst++ = ((src[0]&0xf8)<<8) | ((src[1]&0xf8)<<3) | (src[2] >> 3); // RGB
  92 #endif
  93                                         src += 3;
  94                                 }
  95                                 dst += req_w - width;
  96                         }
  97                         break;
  98                 }
  99
 100                 case READPNG_FONT:
 101                 {
 102                         int x, y, x1, y1;
 103                         unsigned char *dst = dest;
 104                         if (info_ptr->width != req_w || info_ptr->height != req_h)
 105                         {
 106                                 lprintf(__FILE__ ": unexpected font image size %dx%d, needed %dx%d\n",
 107                                         (int)info_ptr->width, (int)info_ptr->height, req_w, req_h);
 108                                 break;
 109                         }
 110                         if (info_ptr->pixel_depth != 8)
 111                         {
 112                                 lprintf(__FILE__ ": font image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
 113                                 break;
 114                         }
 115                         for (y = 0; y < 16; y++)
 116                         {
 117                                 for (x = 0; x < 16; x++)
 118                                 {
 119                                         /* 16x16 grid of syms */
 120                                         int sym_w = req_w / 16;
 121                                         int sym_h = req_h / 16;
 122                                         for (y1 = 0; y1 < sym_h; y1++)
 123                                         {
 124                                                 unsigned char *src = row_ptr[y*sym_h + y1] + x*sym_w;
 125                                                 for (x1 = sym_w/2; x1 > 0; x1--, src+=2)
 126                                                         *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
 127                                         }
 128                                 }
 129                         }
 130                         break;
 131                 }
 132
 133                 case READPNG_SELECTOR:
 134                 {
 135                         int x1, y1;
 136                         unsigned char *dst = dest;
 137                         if (info_ptr->width != req_w || info_ptr->height != req_h)
 138                         {
 139                                 lprintf(__FILE__ ": unexpected selector image size %ix%i, needed %dx%d\n",
 140                                         (int)info_ptr->width, (int)info_ptr->height, req_w, req_h);
 141                                 break;
 142                         }
 143                         if (info_ptr->pixel_depth != 8)
 144                         {
 145                                 lprintf(__FILE__ ": selector image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
 146                                 break;
 147                         }
 148                         for (y1 = 0; y1 < req_h; y1++)
 149                         {
 150                                 unsigned char *src = row_ptr[y1];
 151                                 for (x1 = req_w/2; x1 > 0; x1--, src+=2)
 152                                         *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
 153                         }
 154                         break;
 155                 }
 156
 157                 case READPNG_24:
 158                 {
 159                         int height, width, h;
 160                         unsigned char *dst = dest;
 161                         if (info_ptr->pixel_depth != 24)
 162                         {
 163                                 lprintf(__FILE__ ": image uses %ibpp, needed 24bpp\n", info_ptr->pixel_depth);
 164                                 break;
 165                         }
 166                         height = info_ptr->height;
 167                         if (height > req_h)
 168                                 height = req_h;
 169                         width = info_ptr->width;
 170                         if (width > req_w)
 171                                 width = req_w;
 172
 173                         for (h = 0; h < height; h++)
 174                         {
 175                                 int len = width;
 176                                 unsigned char *src = row_ptr[h];
 177                                 dst += (req_w - width) * 3;
 178                                 for (len = width; len > 0; len--, dst+=3, src+=3)
 179                                         dst[0] = src[2], dst[1] = src[1], dst[2] = src[0];
 180                         }
 181                         break;
 182                 }
 183         }
 184
 185
 186         ret = 0;
 187 done:
 188         png_destroy_read_struct(&png_ptr, info_ptr ? &info_ptr : NULL, (png_infopp)NULL);
 189         fclose(fp);
 190         return ret;
 191 }
 192
 193