Merge pull request #6 from saurabhb17/master

minor additions

1 files changed, 118 insertions, 0 deletions

diff --git a/potrace/bitmap.h b/potrace/bitmap.h
new file mode 100644
index 0000000..6885fc3
--- /dev/null
+++ b/potrace/bitmap.h
@@ -0,0 +1,118 @@
+/* Copyright (C) 2001-2007 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. */
+
+#ifndef BITMAP_H
+#define BITMAP_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <stdlib.h>
+
+/* The bitmap type is defined in potracelib.h */
+#include <potracelib.h>
+
+/* The present file defines some convenient macros and static inline
+ *  functions for accessing bitmaps. Since they only produce inline
+ *  code, they can be conveniently shared by the library and frontends,
+ *  if desired */
+
+/* ---------------------------------------------------------------------- */
+/* some measurements */
+
+#define BM_WORDSIZE ( (int) sizeof(potrace_word) )
+#define BM_WORDBITS (8 * BM_WORDSIZE)
+#define BM_HIBIT    ( ( (potrace_word) 1 ) << (BM_WORDBITS - 1) )
+#define BM_ALLBITS  (~(potrace_word) 0)
+
+/* macros for accessing pixel at index (x,y). U* macros omit the
+ *  bounds check. */
+
+#define bm_scanline( bm, y )   ( (bm)->map + (y) * (bm)->dy )
+#define bm_index( bm, x, y )   (&bm_scanline( bm, y )[(x) / BM_WORDBITS])
+#define bm_mask( x )           ( BM_HIBIT >> ( (x) & (BM_WORDBITS - 1) ) )
+#define bm_range( x, a )       ( (int) (x) >= 0 && (int) (x) < (a) )
+#define bm_safe( bm, x, y )    ( bm_range( x, (bm)->w ) && bm_range( y, (bm)->h ) )
+#define BM_UGET( bm, x, y )    ( ( *bm_index( bm, x, y ) & bm_mask( x ) ) != 0 )
+#define BM_USET( bm, x, y )    ( *bm_index( bm, x, y ) |= bm_mask( x ) )
+#define BM_UCLR( bm, x, y )    ( *bm_index( bm, x, y ) &= ~bm_mask( x ) )
+#define BM_UINV( bm, x, y )    ( *bm_index( bm, x, y ) ^= bm_mask( x ) )
+#define BM_UPUT( bm, x, y, b ) ( (b) ? BM_USET( bm, x, y ) : BM_UCLR( bm, x, y ) )
+#define BM_GET( bm, x, y )     (bm_safe( bm, x, y ) ? BM_UGET( bm, x, y ) : 0)
+#define BM_SET( bm, x, y )     (bm_safe( bm, x, y ) ? BM_USET( bm, x, y ) : 0)
+#define BM_CLR( bm, x, y )     (bm_safe( bm, x, y ) ? BM_UCLR( bm, x, y ) : 0)
+#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)
+
+/* free the given bitmap. Leaves errno untouched. */
+static inline void bm_free( potrace_bitmap_t* bm )
+{
+    if( bm )
+    {
+        free( bm->map );
+    }
+    free( bm );
+}
+
+
+/* return new un-initialized bitmap. NULL with errno on error */
+static inline potrace_bitmap_t* bm_new( int w, int h )
+{
+    potrace_bitmap_t* bm;
+    int dy = (w + BM_WORDBITS - 1) / BM_WORDBITS;
+
+    bm = (potrace_bitmap_t*) malloc( sizeof(potrace_bitmap_t) );
+    if( !bm )
+    {
+        return NULL;
+    }
+    bm->w   = w;
+    bm->h   = h;
+    bm->dy  = dy;
+    bm->map = (potrace_word*) malloc( dy * h * BM_WORDSIZE );
+    if( !bm->map )
+    {
+        free( bm );
+        return NULL;
+    }
+    return bm;
+}
+
+
+/* clear the given bitmap. Set all bits to c. */
+static inline void bm_clear( potrace_bitmap_t* bm, int c )
+{
+    memset( bm->map, c ? -1 : 0, bm->dy * bm->h * BM_WORDSIZE );
+}
+
+
+/* duplicate the given bitmap. Return NULL on error with errno set. */
+static inline potrace_bitmap_t* bm_dup( const potrace_bitmap_t* bm )
+{
+    potrace_bitmap_t* bm1 = bm_new( bm->w, bm->h );
+
+    if( !bm1 )
+    {
+        return NULL;
+    }
+    memcpy( bm1->map, bm->map, bm->dy * bm->h * BM_WORDSIZE );
+    return bm1;
+}
+
+
+/* invert the given bitmap. */
+static inline void bm_invert( potrace_bitmap_t* bm )
+{
+    int i;
+
+    for( i = 0; i < bm->dy * bm->h; i++ )
+    {
+        bm->map[i] ^= BM_ALLBITS;
+    }
+}
+
+
+#endif /* BITMAP_H */