Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 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 | |
Torne (Richard Coles) | 5821806 | 2012-11-14 11:43:16 +0000 | [diff] [blame] | 55 | } // namespace printing |