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