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      1 // Copyright (c) 2012 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 #ifndef UI_GFX_SAFE_INTEGER_CONVERSIONS_H_
      6 #define UI_GFX_SAFE_INTEGER_CONVERSIONS_H_
      7 
      8 #include <cmath>
      9 #include <limits>
     10 
     11 #include "ui/gfx/gfx_export.h"
     12 
     13 namespace gfx {
     14 
     15 inline int ClampToInt(float value) {
     16   if (value != value)
     17     return 0; // no int NaN.
     18   if (value >= std::numeric_limits<int>::max())
     19     return std::numeric_limits<int>::max();
     20   if (value <= std::numeric_limits<int>::min())
     21     return std::numeric_limits<int>::min();
     22   return static_cast<int>(value);
     23 }
     24 
     25 inline int ToFlooredInt(float value) {
     26   return ClampToInt(std::floor(value));
     27 }
     28 
     29 inline int ToCeiledInt(float value) {
     30   return ClampToInt(std::ceil(value));
     31 }
     32 
     33 inline int ToRoundedInt(float value) {
     34   float rounded;
     35   if (value >= 0.0f)
     36     rounded = std::floor(value + 0.5f);
     37   else
     38     rounded = std::ceil(value - 0.5f);
     39   return ClampToInt(rounded);
     40 }
     41 
     42 inline bool IsExpressibleAsInt(float value) {
     43   if (value != value)
     44     return false; // no int NaN.
     45   if (value > std::numeric_limits<int>::max())
     46     return false;
     47   if (value < std::numeric_limits<int>::min())
     48     return false;
     49   return true;
     50 }
     51 
     52 }  // namespace gfx
     53 
     54 #endif  // UI_GFX_SAFE_INTEGER_CONVERSIONS_H_
     55