1 files changed, 131 insertions, 0 deletions
diff --git a/include/tools/helpers.hxx b/include/tools/helpers.hxx
new file mode 100644
index 000000000..1d00bad71
--- /dev/null
+++ b/include/tools/helpers.hxx
@@ -0,0 +1,131 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+#ifndef INCLUDED_TOOLS_HELPERS_HXX
+#define INCLUDED_TOOLS_HELPERS_HXX
+
+#include <sal/config.h>
+#include <sal/types.h>
+#include <o3tl/safeint.hxx>
+#include <cassert>
+#include <type_traits>
+
+template<typename T>
+inline
+typename std::enable_if<
+             std::is_signed<T>::value || std::is_floating_point<T>::value, long >::type
+MinMax(T nVal, long nMin, long nMax)
+{
+    assert(nMin <= nMax);
+    if (nVal >= nMin)
+    {
+        if (nVal <= nMax)
+            return static_cast<long>(nVal);
+        else
+           return nMax;
+    }
+    else
+    {
+        return nMin;
+    }
+}
+
+template<typename T>
+inline
+typename std::enable_if<
+             std::is_unsigned<T>::value, long >::type
+MinMax(T nVal, long nMin, long nMax)
+{
+    assert(nMin <= nMax);
+    if (nMax < 0)
+    {
+        return nMax;
+    }
+    else
+    {
+        if (nMin < 0 || nVal >= static_cast<unsigned long>(nMin))
+        {
+            if (nVal <= static_cast<unsigned long>(nMax))
+                return static_cast<long>(nVal);
+            else
+                return nMax;
+        }
+        else
+        {
+            return nMin;
+        }
+    }
+}
+
+inline sal_uInt32 AlignedWidth4Bytes(sal_uInt32 nWidthBits)
+{
+    if (nWidthBits > SAL_MAX_UINT32 - 31)
+        nWidthBits = SAL_MAX_UINT32;
+    else
+        nWidthBits += 31;
+    return (nWidthBits >> 5) << 2;
+}
+
+inline long FRound( double fVal )
+{
+    return fVal > 0.0 ? static_cast<long>( fVal + 0.5 ) : -static_cast<long>( -fVal + 0.5 );
+}
+
+//valid range:  (-180,180]
+template <typename T>
+[[nodiscard]] inline typename std::enable_if<std::is_signed<T>::value, T>::type
+NormAngle180(T angle)
+{
+    while (angle <= -180)
+        angle += 360;
+    while (angle > 180)
+        angle -= 360;
+    return angle;
+}
+
+//valid range:  [0,360)
+template <typename T> [[nodiscard]] inline T NormAngle360(T angle)
+{
+    while (angle < 0)
+        angle += 360;
+    while (angle >= 360)
+        angle -= 360;
+    return angle;
+}
+
+/** Convert 100th-mm to twips
+
+    A twip is 1/20 of a point, one inch is equal to 72 points, and
+    one inch is 2,540 100th-mm.
+
+    Thus:
+        twips = n * 72 / 2,540 / 20
+              = n * 72 / 127
+
+    Adding 63 (half of 127) fixes truncation issues in int arithmetic.
+
+    This formula is (n>=0) ? (n*72+63) / 127 : (n*72-63) / 127
+ */
+inline sal_Int64 sanitiseMm100ToTwip(sal_Int64 n)
+{
+    if (n >= 0)
+    {
+        if (o3tl::checked_multiply<sal_Int64>(n, 72, n) || o3tl::checked_add<sal_Int64>(n, 63, n))
+            n = SAL_MAX_INT64;
+    }
+    else
+    {
+        if (o3tl::checked_multiply<sal_Int64>(n, 72, n) || o3tl::checked_sub<sal_Int64>(n, 63, n))
+            n = SAL_MIN_INT64;
+    }
+    return n / 127; // 127 is 2,540 100th-mm divided by 20pts
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */