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_TABLE_CORE_HORIZONTAL_METRICS_TABLE_H_
18#define SFNTLY_CPP_SRC_SFNTLY_TABLE_CORE_HORIZONTAL_METRICS_TABLE_H_
19
20#include "sfntly/table/table.h"
21#include "sfntly/table/table_based_table_builder.h"
22
23namespace sfntly {
24
25// A Horizontal Metrics table - 'hmtx'.
26class HorizontalMetricsTable : public Table,
27                               public RefCounted<HorizontalMetricsTable> {
28 public:
29  // Builder for a Horizontal Metrics Table - 'hmtx'.
30  class Builder : public TableBasedTableBuilder, public RefCounted<Builder> {
31   public:
32    // Constructor scope altered to public because C++ does not allow base
33    // class to instantiate derived class with protected constructors.
34    Builder(Header* header, WritableFontData* data);
35    Builder(Header* header, ReadableFontData* data);
36    virtual ~Builder();
37
38    virtual CALLER_ATTACH FontDataTable* SubBuildTable(ReadableFontData* data);
39    static CALLER_ATTACH Builder* CreateBuilder(Header* header,
40                                                WritableFontData* data);
41
42    void SetNumberOfHMetrics(int32_t num_hmetrics);
43    void SetNumGlyphs(int32_t num_glyphs);
44
45   private:
46    int32_t num_hmetrics_;
47    int32_t num_glyphs_;
48  };
49
50  virtual ~HorizontalMetricsTable();
51  int32_t NumberOfHMetrics();
52  int32_t NumberOfLSBs();
53  int32_t HMetricAdvanceWidth(int32_t entry);
54  int32_t HMetricLSB(int32_t entry);
55  int32_t LsbTableEntry(int32_t entry);
56  int32_t AdvanceWidth(int32_t glyph_id);
57  int32_t LeftSideBearing(int32_t glyph_id);
58
59 private:
60  struct Offset {
61    enum {
62      // hMetrics
63      kHMetricsStart = 0,
64      kHMetricsSize = 4,
65
66      // Offset within an hMetric
67      kHMetricsAdvanceWidth = 0,
68      kHMetricsLeftSideBearing = 2,
69
70      kLeftSideBearingSize = 2
71    };
72  };
73
74  HorizontalMetricsTable(Header* header,
75                         ReadableFontData* data,
76                         int32_t num_hmetrics,
77                         int32_t num_glyphs);
78
79  int32_t num_hmetrics_;
80  int32_t num_glyphs_;
81};
82typedef Ptr<HorizontalMetricsTable> HorizontalMetricsTablePtr;
83typedef Ptr<HorizontalMetricsTable::Builder> HorizontalMetricsTableBuilderPtr;
84
85}  // namespace sfntly
86
87#endif  // SFNTLY_CPP_SRC_SFNTLY_TABLE_CORE_HORIZONTAL_METRICS_TABLE_H_
88