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
22namespace sfntly {
23
24class FontMath {
25 public:
26  static int32_t Log2(int32_t a) {
27    int r = 0;  // r will be lg(a)
28    while (a != 0) {
29      a >>= 1;
30      r++;
31    }
32    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  static int32_t PaddingRequired(int32_t size, int32_t alignment_size) {
42    int32_t padding = alignment_size - (size % alignment_size);
43    return padding == alignment_size ? 0 : padding;
44  }
45};
46
47}  // namespace sfntly
48
49#endif  // SFNTLY_CPP_SRC_SFNTLY_MATH_FONT_MATH_H_
50