From 13aacae3ac6afc8437f84527d0b5f564d7558cd1 Mon Sep 17 00:00:00 2001
From: Robert Vollmert <rvollmert@gmx.net>
Date: Sat, 10 Oct 2009 21:32:50 +0200
Subject: Implement bit array class.

---
 crawl-ref/source/bitary.cc    | 76 +++++++++++++++++++++++++++++++++++++++++++
 crawl-ref/source/bitary.h     | 35 ++++++++++++++++++++
 crawl-ref/source/makefile.obj |  1 +
 3 files changed, 112 insertions(+)
 create mode 100644 crawl-ref/source/bitary.cc
 create mode 100644 crawl-ref/source/bitary.h

(limited to 'crawl-ref/source')

diff --git a/crawl-ref/source/bitary.cc b/crawl-ref/source/bitary.cc
new file mode 100644
index 0000000000..d822dcd327
--- /dev/null
+++ b/crawl-ref/source/bitary.cc
@@ -0,0 +1,76 @@
+/*
+ *  File:         bitary.cc
+ *  Summary:      Bit array data type.
+ *  Created by:   Robert Vollmert
+ */
+
+#include "AppHdr.h"
+
+#include "bitary.h"
+
+#include "debug.h"
+
+#define LONGSIZE (sizeof(unsigned long)*8)
+
+bit_array::bit_array(unsigned long s)
+    : size(s)
+{
+    nwords = (int) ((size + LONGSIZE - 1) / LONGSIZE);
+    data = new unsigned long[nwords];
+    reset();
+}
+
+bit_array::~bit_array()
+{
+    delete[] data;
+}
+
+void bit_array::reset()
+{
+    for (int w = 0; w < nwords; ++w)
+        data[w] = 0;
+}
+
+bool bit_array::get(unsigned long index) const
+{
+    ASSERT(index < size);
+    int w = index / LONGSIZE;
+    int b = index % LONGSIZE;
+    return (data[w] & (1UL << b));
+}
+
+void bit_array::set(unsigned long index, bool value)
+{
+    ASSERT(index < size);
+    int w = index / LONGSIZE;
+    int b = index % LONGSIZE;
+    if (value)
+        data[w] |= (1UL << b);
+    else
+        data[w] &= ~(1UL << b);
+}
+
+bit_array& bit_array::operator |= (const bit_array& other)
+{
+    ASSERT(size == other.size);
+    for (int w = 0; w < nwords; ++w)
+        data[w] |= other.data[w];
+    return (*this);
+}
+
+bit_array& bit_array::operator &= (const bit_array& other)
+{
+    ASSERT(size == other.size);
+    for (int w = 0; w < nwords; ++w)
+        data[w] &= other.data[w];
+    return (*this);
+}
+
+bit_array bit_array::operator & (const bit_array& other) const
+{
+    ASSERT(size == other.size);
+    bit_array res = bit_array(size);
+    for (int w = 0; w < nwords; ++w)
+        res.data[w] = data[w] & other.data[w];
+    return (res);
+}
diff --git a/crawl-ref/source/bitary.h b/crawl-ref/source/bitary.h
new file mode 100644
index 0000000000..110a9e846c
--- /dev/null
+++ b/crawl-ref/source/bitary.h
@@ -0,0 +1,35 @@
+/*
+ *  File:         bitary.h
+ *  Summary:      Bit array data type.
+ *  Created by:   Robert Vollmert
+ *
+ * Just contains the operations required by los.cc
+ * for the moment.
+ */
+
+#ifndef BITARY_H
+#define BITARY_H
+
+struct bit_array
+{
+public:
+    bit_array(unsigned long size = 0);
+    ~bit_array();
+
+    void reset();
+
+    bool get(unsigned long index) const;
+    void set(unsigned long index, bool value = true);
+
+    bit_array& operator |= (const bit_array& other);
+    bit_array& operator &= (const bit_array& other);
+    bit_array  operator & (const bit_array& other) const;
+
+protected:
+    unsigned long size;
+    int nwords;
+    unsigned long *data;
+};
+
+#endif
+
diff --git a/crawl-ref/source/makefile.obj b/crawl-ref/source/makefile.obj
index aaa4f4d168..d2e6447573 100644
--- a/crawl-ref/source/makefile.obj
+++ b/crawl-ref/source/makefile.obj
@@ -5,6 +5,7 @@ artefact.o \
 acr.o \
 arena.o \
 beam.o \
+bitary.o \
 branch.o \
 chardump.o \
 cio.o \
-- 
cgit v1.2.3-54-g00ecf