1 files changed, 94 insertions, 0 deletions

diff --git a/src/grail-bits.c b/src/grail-bits.c
new file mode 100644
index 0000000..1b38d58
--- /dev/null
+++ b/src/grail-bits.c
@@ -0,0 +1,94 @@
+/*****************************************************************************
+ *
+ * grail - Gesture Recognition And Instantiation Library
+ *
+ * Copyright (C) 2010 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *      Henrik Rydberg <rydberg@bitmath.org>
+ *
+ ****************************************************************************/
+
+#include "grail-bits.h"
+
+static const int grail_bits_in_byte[256] =
+{
+        0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+        1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+        1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+        2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+        1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+        2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+        2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+        3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
+};
+
+static const int grail_first_set_bit[256] =
+{
+        -1,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+};
+
+void grail_mask_set_mask(grail_mask_t *a, const grail_mask_t *b, int bytes)
+{
+        while (bytes--)
+                *a++ |= *b++;
+}
+
+void grail_mask_clear_mask(grail_mask_t *a, const grail_mask_t *b, int bytes)
+{
+        while (bytes--)
+                *a++ &= ~*b++;
+}
+
+int grail_mask_count(const grail_mask_t *mask, int bytes)
+{
+        int count = 0;
+        while (bytes--)
+                count += grail_bits_in_byte[*mask++];
+        return count;
+}
+
+int grail_mask_get_first(const grail_mask_t *mask, int bytes)
+{
+        int k;
+        for (k = 0; k < bytes; k++)
+                if (mask[k])
+                        return (k << 3) | grail_first_set_bit[mask[k]];
+        return -1;
+}
+
+int grail_mask_get_next(int i, const grail_mask_t *mask, int bytes)
+{
+        int k = ++i >> 3;
+        if (k < bytes) {
+                i = grail_first_set_bit[mask[k] & (~0 << (i & 7))];
+                if (i >= 0)
+                        return (k << 3) | i;
+                while (++k < bytes) {
+                        i = grail_first_set_bit[mask[k]];
+                        if (i >= 0)
+                                return (k << 3) | i;
+                }
+        }
+        return -1;
+}