1// Copyright (c) 2011 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#include "printing/units.h" 6 7#include "base/logging.h" 8#include "printing/print_job_constants.h" 9 10namespace printing { 11 12int ConvertUnit(int value, int old_unit, int new_unit) { 13 DCHECK_GT(new_unit, 0); 14 DCHECK_GT(old_unit, 0); 15 // With integer arithmetic, to divide a value with correct rounding, you need 16 // to add half of the divisor value to the dividend value. You need to do the 17 // reverse with negative number. 18 if (value >= 0) { 19 return ((value * new_unit) + (old_unit / 2)) / old_unit; 20 } else { 21 return ((value * new_unit) - (old_unit / 2)) / old_unit; 22 } 23} 24 25double ConvertUnitDouble(double value, double old_unit, double new_unit) { 26 DCHECK_GT(new_unit, 0); 27 DCHECK_GT(old_unit, 0); 28 return value * new_unit / old_unit; 29} 30 31int ConvertMilliInchToHundredThousanthMeter(int milli_inch) { 32 // 1" == 25.4 mm 33 // 1" == 25400 um 34 // 0.001" == 25.4 um 35 // 0.001" == 2.54 cmm 36 return ConvertUnit(milli_inch, 100, 254); 37} 38 39int ConvertHundredThousanthMeterToMilliInch(int cmm) { 40 return ConvertUnit(cmm, 254, 100); 41} 42 43int ConvertPixelsToPoint(int pixels) { 44 return ConvertUnit(pixels, kPixelsPerInch, kPointsPerInch); 45} 46 47double ConvertPixelsToPointDouble(double pixels) { 48 return ConvertUnitDouble(pixels, kPixelsPerInch, kPointsPerInch); 49} 50 51double ConvertPointsToPixelDouble(double points) { 52 return ConvertUnitDouble(points, kPointsPerInch, kPixelsPerInch); 53} 54 55} // namespace printing 56