1 files changed, 133 insertions, 18 deletions

diff --git a/Build/source/libs/potrace/potrace-src/src/bitmap.h b/Build/source/libs/potrace/potrace-src/src/bitmap.h
index 7b5a94bb161..2e91ab1e7d7 100644
--- a/Build/source/libs/potrace/potrace-src/src/bitmap.h
+++ b/Build/source/libs/potrace/potrace-src/src/bitmap.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2015 Peter Selinger.
+/* Copyright (C) 2001-2017 Peter Selinger.
    This file is part of Potrace. It is free software and it is covered
    by the GNU General Public License. See the file COPYING for details. */
 
@@ -45,26 +45,71 @@
 #define BM_INV(bm, x, y) (bm_safe(bm, x, y) ? BM_UINV(bm, x, y) : 0)
 #define BM_PUT(bm, x, y, b) (bm_safe(bm, x, y) ? BM_UPUT(bm, x, y, b) : 0)
 
+/* calculate the size, in bytes, required for the data area of a
+   bitmap of the given dy and h. Assume h >= 0. Return -1 if the size
+   does not fit into the ptrdiff_t type. */
+static inline ptrdiff_t getsize(int dy, int h) {
+  ptrdiff_t size;
+
+  if (dy < 0) {
+    dy = -dy;
+  }
+  
+  size = (ptrdiff_t)dy * (ptrdiff_t)h * (ptrdiff_t)BM_WORDSIZE;
+
+  /* check for overflow error */
+  if (size < 0 || (h != 0 && dy != 0 && size / h / dy != BM_WORDSIZE)) {
+    return -1;
+  }
+
+  return size;
+}
+
+/* return the size, in bytes, of the data area of the bitmap. Return
+   -1 if the size does not fit into the ptrdiff_t type; however, this
+   cannot happen if the bitmap is well-formed, i.e., if created with
+   bm_new or bm_dup. */
+static inline ptrdiff_t bm_size(const potrace_bitmap_t *bm) {
+  return getsize(bm->dy, bm->h);
+}
+
+/* calculate the base address of the bitmap data. Assume that the
+   bitmap is well-formed, i.e., its size fits into the ptrdiff_t type.
+   This is the case if created with bm_new or bm_dup. The base address
+   may differ from bm->map if dy is negative */
+static inline potrace_word *bm_base(const potrace_bitmap_t *bm) {
+  int dy = bm->dy;
+
+  if (dy >= 0 || bm->h == 0) {
+    return bm->map;
+  } else {
+    return bm_scanline(bm, bm->h - 1);
+  }  
+}
+
 /* free the given bitmap. Leaves errno untouched. */
 static inline void bm_free(potrace_bitmap_t *bm) {
-  if (bm) {
-    free(bm->map);
+  if (bm && bm->map) {
+    free(bm_base(bm));
   }
   free(bm);
 }
 
-/* return new un-initialized bitmap. NULL with errno on error.
+/* return new bitmap initialized to 0. NULL with errno on error.
    Assumes w, h >= 0. */
 static inline potrace_bitmap_t *bm_new(int w, int h) {
   potrace_bitmap_t *bm;
   int dy = w == 0 ? 0 : (w - 1) / BM_WORDBITS + 1;
-  ptrdiff_t size = (ptrdiff_t)dy * (ptrdiff_t)h * (ptrdiff_t)BM_WORDSIZE;
+  ptrdiff_t size;
 
-  /* check for overflow error */
-  if (size < 0 || (h != 0 && dy != 0 && size / h / dy != BM_WORDSIZE)) {
+  size = getsize(dy, h);
+  if (size < 0) {
     errno = ENOMEM;
     return NULL;
   }
+  if (size == 0) {
+    size = 1; /* make sure calloc() doesn't return NULL */
+  } 
 
   bm = (potrace_bitmap_t *) malloc(sizeof(potrace_bitmap_t));
   if (!bm) {
@@ -73,7 +118,7 @@ static inline potrace_bitmap_t *bm_new(int w, int h) {
   bm->w = w;
   bm->h = h;
   bm->dy = dy;
-  bm->map = (potrace_word *) malloc(size);
+  bm->map = (potrace_word *) calloc(1, size);
   if (!bm->map) {
     free(bm);
     return NULL;
@@ -81,33 +126,103 @@ static inline potrace_bitmap_t *bm_new(int w, int h) {
   return bm;
 }
 
-/* clear the given bitmap. Set all bits to c. */
+/* clear the given bitmap. Set all bits to c. Assumes a well-formed
+   bitmap. */
 static inline void bm_clear(potrace_bitmap_t *bm, int c) {
   /* Note: if the bitmap was created with bm_new, then it is
      guaranteed that size will fit into the ptrdiff_t type. */
-  ptrdiff_t size = (ptrdiff_t)bm->dy * (ptrdiff_t)bm->h * (ptrdiff_t)BM_WORDSIZE;
-  memset(bm->map, c ? -1 : 0, size);
+  ptrdiff_t size = bm_size(bm);
+  memset(bm_base(bm), c ? -1 : 0, size);
 }
 
-/* duplicate the given bitmap. Return NULL on error with errno set. */
+/* duplicate the given bitmap. Return NULL on error with errno
+   set. Assumes a well-formed bitmap. */
 static inline potrace_bitmap_t *bm_dup(const potrace_bitmap_t *bm) {
   potrace_bitmap_t *bm1 = bm_new(bm->w, bm->h);
-  ptrdiff_t size = (ptrdiff_t)bm->dy * (ptrdiff_t)bm->h * (ptrdiff_t)BM_WORDSIZE;
+  int y;
+  
   if (!bm1) {
     return NULL;
   }
-  memcpy(bm1->map, bm->map, size);
+  for (y=0; y < bm->h; y++) {
+    memcpy(bm_scanline(bm1, y), bm_scanline(bm, y), (size_t)bm1->dy * (size_t)BM_WORDSIZE);
+  }
   return bm1;
 }
 
 /* invert the given bitmap. */
 static inline void bm_invert(potrace_bitmap_t *bm) {
-  ptrdiff_t i;
-  ptrdiff_t size = (ptrdiff_t)bm->dy * (ptrdiff_t)bm->h;
+  int dy = bm->dy;
+  int y;
+  int i;
+  potrace_word *p;
 
-  for (i = 0; i < size; i++) {
-    bm->map[i] ^= BM_ALLBITS;
+  if (dy < 0) {
+    dy = -dy;
+  }
+  
+  for (y=0; y < bm->h; y++) {
+    p = bm_scanline(bm, y);
+    for (i=0; i < dy; i++) {
+      p[i] ^= BM_ALLBITS;
+    }
+  }
+}
+
+/* turn the given bitmap upside down. This does not move the bitmap
+   data or change the bm_base() address. */
+static inline void bm_flip(potrace_bitmap_t *bm) {
+  int dy = bm->dy;
+
+  if (bm->h == 0 || bm->h == 1) {
+    return;
+  }
+  
+  bm->map = bm_scanline(bm, bm->h - 1);
+  bm->dy = -dy;
+}
+
+/* resize the bitmap to the given new height. The bitmap data remains
+   bottom-aligned (truncated at the top) when dy >= 0 and top-aligned
+   (truncated at the bottom) when dy < 0. Return 0 on success, or 1 on
+   error with errno set. If the new height is <= the old one, no error
+   should occur. If the new height is larger, the additional bitmap
+   data is *not* initialized. */
+static inline int bm_resize(potrace_bitmap_t *bm, int h) {
+  int dy = bm->dy;
+  ptrdiff_t newsize;
+  potrace_word *newmap;
+
+  if (dy < 0) {
+    bm_flip(bm);
+  }
+  
+  newsize = getsize(dy, h);
+  if (newsize < 0) {
+    errno = ENOMEM;
+    goto error;
+  }
+  if (newsize == 0) {
+    newsize = 1; /* make sure realloc() doesn't return NULL */
+  }
+  
+  newmap = (potrace_word *)realloc(bm->map, newsize);
+  if (newmap == NULL) {
+    goto error;
+  }
+  bm->map = newmap;
+  bm->h = h;
+
+  if (dy < 0) {
+    bm_flip(bm);
+  }
+  return 0;
+  
+ error:
+  if (dy < 0) {
+    bm_flip(bm);
   }
+  return 1;  
 }
 
 #endif /* BITMAP_H */