code.delx.au - refind/blob - libeg/lodepng_xtra.c

   1 /*
   2  * Additional functions to support LodePNG for use in rEFInd
   3  *
   4  * copyright (c) 2013 by by Roderick W. Smith, and distributed
   5  * under the terms of the GNU GPL v3, or (at your option) any
   6  * later version.
   7  *
   8  * See http://lodev.org/lodepng/ for the original LodePNG.
   9  *
  10  */
  11 /*
  12  * This program is free software: you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation, either version 3 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #include "global.h"
  27 #include "../refind/screen.h"
  28 #include "lodepng.h"
  29
  30 // EFI's equivalent of realloc requires the original buffer's size as an
  31 // input parameter, which the standard libc realloc does not require. Thus,
  32 // I've modified lodepng_malloc() to allocate more memory to store this data,
  33 // and lodepng_realloc() can then read it when required. Because the size is
  34 // stored at the start of the allocated area, these functions are NOT
  35 // interchangeable with the standard EFI functions; memory allocated via
  36 // lodepng_malloc() should be freed via lodepng_free(), and myfree() should
  37 // NOT be used with memory allocated via AllocatePool() or AllocateZeroPool()!
  38
  39 void* lodepng_malloc(size_t size) {
  40    void *ptr;
  41
  42    ptr = AllocateZeroPool(size + sizeof(size_t));
  43    if (ptr) {
  44       *(size_t *) ptr = size;
  45       return ((size_t *) ptr) + 1;
  46    } else {
  47       return NULL;
  48    }
  49 } // void* lodepng_malloc()
  50
  51 void lodepng_free (void *ptr) {
  52    if (ptr) {
  53       ptr = (void *) (((size_t *) ptr) - 1);
  54       FreePool(ptr);
  55    }
  56 } // void lodepng_free()
  57
  58 static size_t report_size(void *ptr) {
  59    if (ptr)
  60       return * (((size_t *) ptr) - 1);
  61    else
  62       return 0;
  63 } // size_t report_size()
  64
  65 void* lodepng_realloc(void *ptr, size_t new_size) {
  66    size_t *new_pool;
  67    size_t old_size;
  68
  69    new_pool = lodepng_malloc(new_size);
  70    if (new_pool && ptr) {
  71       old_size = report_size(ptr);
  72       CopyMem(new_pool, ptr, (old_size < new_size) ? old_size : new_size);
  73    }
  74    return new_pool;
  75 } // lodepng_realloc()
  76
  77 // Finds length of ASCII string, which MUST be NULL-terminated.
  78 int MyStrlen(const char *InString) {
  79    int Length = 0;
  80
  81    if (InString) {
  82       while (InString[Length] != '\0')
  83          Length++;
  84    }
  85    return Length;
  86 } // int MyStrlen()
  87
  88 typedef struct _lode_color {
  89    UINT8 red;
  90    UINT8 green;
  91    UINT8 blue;
  92    UINT8 alpha;
  93 } lode_color;
  94
  95 EG_IMAGE * egDecodePNG(IN UINT8 *FileData, IN UINTN FileDataLength, IN UINTN IconSize, IN BOOLEAN WantAlpha) {
  96    EG_IMAGE *NewImage = NULL;
  97    unsigned Error, Width, Height;
  98    EG_PIXEL *PixelData;
  99    lode_color *LodeData;
 100    UINTN i;
 101
 102    Error = lodepng_decode_memory((unsigned char **) &PixelData, &Width, &Height, (unsigned char*) FileData,
 103                                  (size_t) FileDataLength, LCT_RGBA, 8);
 104
 105    if (Error) {
 106       return NULL;
 107    }
 108
 109    // allocate image structure and buffer
 110    NewImage = egCreateImage(Width, Height, WantAlpha);
 111    if ((NewImage == NULL) || (NewImage->Width != Width) || (NewImage->Height != Height))
 112       return NULL;
 113
 114    LodeData = (lode_color *) PixelData;
 115
 116    // Annoyingly, EFI and LodePNG use different ordering of RGB values in
 117    // their pixel data representations, so we've got to adjust them....
 118    for (i = 0; i < (NewImage->Height * NewImage->Width); i++) {
 119       NewImage->PixelData[i].r = LodeData[i].red;
 120       NewImage->PixelData[i].g = LodeData[i].green;
 121       NewImage->PixelData[i].b = LodeData[i].blue;
 122       if (WantAlpha)
 123          NewImage->PixelData[i].a = LodeData[i].alpha;
 124    }
 125    lodepng_free(PixelData);
 126
 127    return NewImage;
 128 } // EG_IMAGE * egDecodePNG()