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      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 #include "sfntly/table/core/horizontal_metrics_table.h"
     18 #include "sfntly/port/exception_type.h"
     19 
     20 namespace sfntly {
     21 /******************************************************************************
     22  * HorizontalMetricsTable class
     23  ******************************************************************************/
     24 HorizontalMetricsTable::~HorizontalMetricsTable() {}
     25 
     26 int32_t HorizontalMetricsTable::NumberOfHMetrics() {
     27   return num_hmetrics_;
     28 }
     29 
     30 int32_t HorizontalMetricsTable::NumberOfLSBs() {
     31   return num_glyphs_ - num_hmetrics_;
     32 }
     33 
     34 int32_t HorizontalMetricsTable::HMetricAdvanceWidth(int32_t entry) {
     35   if (entry > num_hmetrics_) {
     36 #if !defined (SFNTLY_NO_EXCEPTION)
     37     throw IndexOutOfBoundException();
     38 #endif
     39     return 0;
     40   }
     41   int32_t offset = Offset::kHMetricsStart + (entry * Offset::kHMetricsSize) +
     42                    Offset::kHMetricsAdvanceWidth;
     43   return data_->ReadUShort(offset);
     44 }
     45 
     46 int32_t HorizontalMetricsTable::HMetricLSB(int32_t entry) {
     47   if (entry > num_hmetrics_) {
     48 #if !defined (SFNTLY_NO_EXCEPTION)
     49     throw IndexOutOfBoundException();
     50 #endif
     51     return 0;
     52   }
     53   int32_t offset = Offset::kHMetricsStart + (entry * Offset::kHMetricsSize) +
     54                    Offset::kHMetricsLeftSideBearing;
     55   return data_->ReadShort(offset);
     56 }
     57 
     58 int32_t HorizontalMetricsTable::LsbTableEntry(int32_t entry) {
     59   if (entry > num_hmetrics_) {
     60 #if !defined (SFNTLY_NO_EXCEPTION)
     61     throw IndexOutOfBoundException();
     62 #endif
     63     return 0;
     64   }
     65   int32_t offset = Offset::kHMetricsStart + (entry * Offset::kHMetricsSize) +
     66                    Offset::kLeftSideBearingSize;
     67   return data_->ReadShort(offset);
     68 }
     69 
     70 int32_t HorizontalMetricsTable::AdvanceWidth(int32_t glyph_id) {
     71   if (glyph_id < num_hmetrics_) {
     72     return HMetricAdvanceWidth(glyph_id);
     73   }
     74   return HMetricAdvanceWidth(glyph_id - num_hmetrics_);
     75 }
     76 
     77 int32_t HorizontalMetricsTable::LeftSideBearing(int32_t glyph_id) {
     78   if (glyph_id < num_hmetrics_) {
     79     return HMetricLSB(glyph_id);
     80   }
     81   return LsbTableEntry(glyph_id - num_hmetrics_);
     82 }
     83 
     84 HorizontalMetricsTable::HorizontalMetricsTable(Header* header,
     85                                                ReadableFontData* data,
     86                                                int32_t num_hmetrics,
     87                                                int32_t num_glyphs)
     88     : Table(header, data),
     89       num_hmetrics_(num_hmetrics),
     90       num_glyphs_(num_glyphs) {
     91 }
     92 
     93 /******************************************************************************
     94  * HorizontalMetricsTable::Builder class
     95  ******************************************************************************/
     96 HorizontalMetricsTable::Builder::Builder(Header* header, WritableFontData* data)
     97     : TableBasedTableBuilder(header, data), num_hmetrics_(-1), num_glyphs_(-1) {
     98 }
     99 
    100 HorizontalMetricsTable::Builder::Builder(Header* header, ReadableFontData* data)
    101     : TableBasedTableBuilder(header, data), num_hmetrics_(-1), num_glyphs_(-1) {
    102 }
    103 
    104 HorizontalMetricsTable::Builder::~Builder() {}
    105 
    106 CALLER_ATTACH FontDataTable*
    107     HorizontalMetricsTable::Builder::SubBuildTable(ReadableFontData* data) {
    108   FontDataTablePtr table =
    109       new HorizontalMetricsTable(header(), data, num_hmetrics_, num_glyphs_);
    110   return table.Detach();
    111 }
    112 
    113 CALLER_ATTACH HorizontalMetricsTable::Builder*
    114     HorizontalMetricsTable::Builder::CreateBuilder(Header* header,
    115                                                    WritableFontData* data) {
    116   Ptr<HorizontalMetricsTable::Builder> builder;
    117   builder = new HorizontalMetricsTable::Builder(header, data);
    118   return builder.Detach();
    119 }
    120 
    121 void HorizontalMetricsTable::Builder::SetNumberOfHMetrics(
    122     int32_t num_hmetrics) {
    123   assert(num_hmetrics >= 0);
    124   num_hmetrics_ = num_hmetrics;
    125   HorizontalMetricsTable* table =
    126       down_cast<HorizontalMetricsTable*>(this->GetTable());
    127   table->num_hmetrics_ = num_hmetrics;
    128 }
    129 
    130 void HorizontalMetricsTable::Builder::SetNumGlyphs(int32_t num_glyphs) {
    131   assert(num_glyphs >= 0);
    132   num_glyphs_ = num_glyphs;
    133   HorizontalMetricsTable* table =
    134       down_cast<HorizontalMetricsTable*>(this->GetTable());
    135   table->num_glyphs_ = num_glyphs;
    136 }
    137 
    138 }  // namespace sfntly
    139