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 10 namespace printing { 11 12 int 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 25 double 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 31 int 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 39 int ConvertHundredThousanthMeterToMilliInch(int cmm) { 40 return ConvertUnit(cmm, 254, 100); 41 } 42 43 int ConvertPixelsToPoint(int pixels) { 44 return ConvertUnit(pixels, kPixelsPerInch, kPointsPerInch); 45 } 46 47 double ConvertPixelsToPointDouble(double pixels) { 48 return ConvertUnitDouble(pixels, kPixelsPerInch, kPointsPerInch); 49 } 50 51 double ConvertPointsToPixelDouble(double points) { 52 return ConvertUnitDouble(points, kPointsPerInch, kPixelsPerInch); 53 } 54 55 } // namespace printing 56
