diff options
| -rw-r--r-- | include/tools/helpers.hxx | 16 | ||||
| -rw-r--r-- | tools/CppunitTest_tools_test.mk | 1 | ||||
| -rw-r--r-- | tools/qa/cppunit/test_100mm2twips.cxx | 55 |
3 files changed, 70 insertions, 2 deletions
diff --git a/include/tools/helpers.hxx b/include/tools/helpers.hxx index 8325f095bad8..0a349ea62d1d 100644 --- a/include/tools/helpers.hxx +++ b/include/tools/helpers.hxx @@ -55,7 +55,19 @@ inline long FRound( double fVal ) return fVal > 0.0 ? static_cast<long>( fVal + 0.5 ) : -static_cast<long>( -fVal + 0.5 ); } -// return (n >= 0)? (n*72+63)/127: (n*72-63)/127; +/** 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) @@ -68,7 +80,7 @@ inline sal_Int64 sanitiseMm100ToTwip(sal_Int64 n) if (o3tl::checked_multiply<sal_Int64>(n, 72, n) || o3tl::checked_sub<sal_Int64>(n, 63, n)) n = SAL_MIN_INT64; } - return n / 127; + return n / 127; // 127 is 2,540 100th-mm divided by 20pts } #endif diff --git a/tools/CppunitTest_tools_test.mk b/tools/CppunitTest_tools_test.mk index 2c24b21878fa..7c7b9eab6184 100644 --- a/tools/CppunitTest_tools_test.mk +++ b/tools/CppunitTest_tools_test.mk @@ -25,6 +25,7 @@ $(eval $(call gb_CppunitTest_add_exception_objects,tools_test, \ tools/qa/cppunit/test_color \ tools/qa/cppunit/test_rectangle \ tools/qa/cppunit/test_minmax \ + tools/qa/cppunit/test_100mm2twips \ )) $(eval $(call gb_CppunitTest_use_sdk_api,tools_test)) diff --git a/tools/qa/cppunit/test_100mm2twips.cxx b/tools/qa/cppunit/test_100mm2twips.cxx new file mode 100644 index 000000000000..93eab264f8da --- /dev/null +++ b/tools/qa/cppunit/test_100mm2twips.cxx @@ -0,0 +1,55 @@ +/* -*- 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/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <sal/types.h> +#include <sal/log.hxx> + +#include <cppunit/TestFixture.h> +#include <cppunit/extensions/HelperMacros.h> +#include <cppunit/plugin/TestPlugIn.h> + +#include <tools/helpers.hxx> + +#include <cassert> + +namespace tools +{ +class cm2TwipsTest : public CppUnit::TestFixture +{ +public: + void testConvert() + { + sal_Int32 nActual = sanitiseMm100ToTwip(255); + sal_Int32 nExpected = 145; + CPPUNIT_ASSERT_EQUAL(nExpected, nActual); + + nActual = sanitiseMm100ToTwip(-255); + nExpected = -145; + CPPUNIT_ASSERT_EQUAL(nExpected, nActual); + } + + CPPUNIT_TEST_SUITE(cm2TwipsTest); + CPPUNIT_TEST(testConvert); + CPPUNIT_TEST_SUITE_END(); +}; + +CPPUNIT_TEST_SUITE_REGISTRATION(cm2TwipsTest); +} // namespace tools + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |