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.
   6  *
   7  * See http://lodev.org/lodepng/ for the original LodePNG.
   8  *
   9  */
  10
  11 #include "global.h"
  12 #include "../refind/screen.h"
  13 #include "lodepng.h"
  14
  15 // EFI's equivalent of realloc requires the original buffer's size as an
  16 // input parameter, which the standard libc realloc does not require. Thus,
  17 // I've modified lodepng_malloc() to allocate more memory to store this data,
  18 // and lodepng_realloc() can then read it when required. Because the size is
  19 // stored at the start of the allocated area, these functions are NOT
  20 // interchangeable with the standard EFI functions; memory allocated via
  21 // lodepng_malloc() should be freed via lodepng_free(), and myfree() should
  22 // NOT be used with memory allocated via AllocatePool() or AllocateZeroPool()!
  23
  24 void* lodepng_malloc(size_t size) {
  25    void *ptr;
  26
  27    ptr = AllocateZeroPool(size + sizeof(size_t));
  28    if (ptr) {
  29       *(size_t *) ptr = size;
  30       return ((size_t *) ptr) + 1;
  31    } else {
  32       return NULL;
  33    }
  34 } // void* lodepng_malloc()
  35
  36 void lodepng_free (void *ptr) {
  37    if (ptr) {
  38       ptr = (void *) (((size_t *) ptr) - 1);
  39       FreePool(ptr);
  40    }
  41 } // void lodepng_free()
  42
  43 static size_t report_size(void *ptr) {
  44    if (ptr)
  45       return * (((size_t *) ptr) - 1);
  46    else
  47       return 0;
  48 } // size_t report_size()
  49
  50 void* lodepng_realloc(void *ptr, size_t new_size) {
  51    size_t *new_pool;
  52    size_t old_size;
  53
  54    new_pool = lodepng_malloc(new_size);
  55    if (new_pool && ptr) {
  56       old_size = report_size(ptr);
  57       CopyMem(new_pool, ptr, (old_size < new_size) ? old_size : new_size);
  58    }
  59    return new_pool;
  60 } // lodepng_realloc()
  61
  62 // Finds length of ASCII string, which MUST be NULL-terminated.
  63 int MyStrlen(const char *InString) {
  64    int Length = 0;
  65
  66    if (InString) {
  67       while (InString[Length] != '\0')
  68          Length++;
  69    }
  70    return Length;
  71 } // int MyStrlen()
  72
  73 typedef struct _lode_color {
  74    UINT8 red;
  75    UINT8 green;
  76    UINT8 blue;
  77    UINT8 alpha;
  78 } lode_color;
  79
  80 EG_IMAGE * egDecodePNG(IN UINT8 *FileData, IN UINTN FileDataLength, IN UINTN IconSize, IN BOOLEAN WantAlpha) {
  81    EG_IMAGE *NewImage = NULL;
  82    unsigned Error, Width, Height;
  83    EG_PIXEL *PixelData;
  84    lode_color *LodeData;
  85    UINTN i;
  86
  87    Error = lodepng_decode_memory((unsigned char **) &PixelData, &Width, &Height, (unsigned char*) FileData,
  88                                  (size_t) FileDataLength, LCT_RGBA, 8);
  89
  90    if (Error) {
  91       return NULL;
  92    }
  93
  94    // allocate image structure and buffer
  95    NewImage = egCreateImage(Width, Height, WantAlpha);
  96    if ((NewImage == NULL) || (NewImage->Width != Width) || (NewImage->Height != Height))
  97       return NULL;
  98
  99    LodeData = (lode_color *) PixelData;
 100
 101    // Annoyingly, EFI and LodePNG use different ordering of RGB values in
 102    // their pixel data representations, so we've got to adjust them....
 103    for (i = 0; i < (NewImage->Height * NewImage->Width); i++) {
 104       NewImage->PixelData[i].r = LodeData[i].red;
 105       NewImage->PixelData[i].g = LodeData[i].green;
 106       NewImage->PixelData[i].b = LodeData[i].blue;
 107       if (WantAlpha)
 108          NewImage->PixelData[i].a = LodeData[i].alpha;
 109    }
 110    lodepng_free(PixelData);
 111
 112    return NewImage;
 113 } // EG_IMAGE * egDecodePNG()