Line data    Source code

       1             : /*
       2             :  * Copyright 2011 Google Inc. All Rights Reserved.
       3             :  *
       4             :  * Licensed under the Apache License, Version 2.0 (the "License");
       5             :  * you may not use this file except in compliance with the License.
       6             :  * You may obtain a copy of the License at
       7             :  *
       8             :  *      http://www.apache.org/licenses/LICENSE-2.0
       9             :  *
      10             :  * Unless required by applicable law or agreed to in writing, software
      11             :  * distributed under the License is distributed on an "AS IS" BASIS,
      12             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      13             :  * See the License for the specific language governing permissions and
      14             :  * limitations under the License.
      15             :  */
      16             : 
      17             : #ifndef SFNTLY_CPP_SRC_SFNTLY_MATH_FONT_MATH_H_
      18             : #define SFNTLY_CPP_SRC_SFNTLY_MATH_FONT_MATH_H_
      19             : 
      20             : #include "sfntly/port/type.h"
      21             : 
      22             : namespace sfntly {
      23             : 
      24             : class FontMath {
      25             :  public:
      26           0 :   static int32_t Log2(int32_t a) {
      27           0 :     int r = 0;  // r will be lg(a)
      28           0 :     while (a != 0) {
      29           0 :       a >>= 1;
      30           0 :       r++;
      31             :     }
      32           0 :     return r - 1;
      33             :   }
      34             : 
      35             :   // Calculates the amount of padding needed. The values provided need to be in
      36             :   // the same units. So, if the size is given as the number of bytes then the
      37             :   // alignment size must also be specified as byte size to align to.
      38             :   // @param size the size of the data that may need padding
      39             :   // @param alignmentSize the number of units to align to
      40             :   // @return the number of units needing to be added for alignment
      41           0 :   static int32_t PaddingRequired(int32_t size, int32_t alignment_size) {
      42           0 :     int32_t padding = alignment_size - (size % alignment_size);
      43           0 :     return padding == alignment_size ? 0 : padding;
      44             :   }
      45             : };
      46             : 
      47             : }  // namespace sfntly
      48             : 
      49             : #endif  // SFNTLY_CPP_SRC_SFNTLY_MATH_FONT_MATH_H_