| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <cmath> |
| |
| #include "content/public/common/page_zoom.h" |
| |
| namespace content { |
| |
| const double kMinimumZoomFactor = 0.25; |
| const double kMaximumZoomFactor = 5.0; |
| const double kEpsilon = 0.001; |
| const double kTextSizeMultiplierRatio = 1.2; |
| |
| bool ZoomValuesEqual(double value_a, double value_b) { |
| return (std::fabs(value_a - value_b) <= kEpsilon); |
| } |
| |
| double ZoomLevelToZoomFactor(double zoom_level) { |
| return std::pow(kTextSizeMultiplierRatio, zoom_level); |
| } |
| |
| double ZoomFactorToZoomLevel(double factor) { |
| return std::log(factor) / std::log(kTextSizeMultiplierRatio); |
| } |
| |
| } // namespace content |