dlls/dwrite/opentype.c

   1 /*
   2  *    Methods for dealing with opentype font tables
   3  *
   4  * Copyright 2014 Aric Stewart for CodeWeavers
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #define COBJMACROS
  22
  23 #include "dwrite.h"
  24 #include "dwrite_private.h"
  25
  26 WINE_DEFAULT_DEBUG_CHANNEL(dwrite);
  27
  28 #define DWRITE_MAKE_OPENTYPE_TAG(ch0, ch1, ch2, ch3) \
  29                     ((DWORD)(BYTE)(ch0) | ((DWORD)(BYTE)(ch1) << 8) | \
  30                     ((DWORD)(BYTE)(ch2) << 16) | ((DWORD)(BYTE)(ch3) << 24))
  31
  32 #define MS_TTCF_TAG DWRITE_MAKE_OPENTYPE_TAG('t','t','c','f')
  33 #define MS_OTTO_TAG DWRITE_MAKE_OPENTYPE_TAG('O','T','T','O')
  34
  35 #ifdef WORDS_BIGENDIAN
  36 #define GET_BE_WORD(x) (x)
  37 #define GET_BE_DWORD(x) (x)
  38 #else
  39 #define GET_BE_WORD(x) MAKEWORD(HIBYTE(x), LOBYTE(x))
  40 #define GET_BE_DWORD(x) MAKELONG(GET_BE_WORD(HIWORD(x)), GET_BE_WORD(LOWORD(x)))
  41 #endif
  42
  43 typedef struct {
  44     CHAR TTCTag[4];
  45     DWORD Version;
  46     DWORD numFonts;
  47     DWORD OffsetTable[1];
  48 } TTC_Header_V1;
  49
  50 typedef struct {
  51     DWORD version;
  52     WORD numTables;
  53     WORD searchRange;
  54     WORD entrySelector;
  55     WORD rangeShift;
  56 } TTC_SFNT_V1;
  57
  58 typedef struct {
  59     CHAR tag[4];
  60     DWORD checkSum;
  61     DWORD offset;
  62     DWORD length;
  63 } TT_TableRecord;
  64
  65 HRESULT analyze_opentype_font(const void* font_data, UINT32* font_count, DWRITE_FONT_FILE_TYPE *file_type, DWRITE_FONT_FACE_TYPE *face_type, BOOL *supported)
  66 {
  67     /* TODO: Do font validation */
  68     const char* tag = font_data;
  69
  70     *supported = FALSE;
  71     *file_type = DWRITE_FONT_FILE_TYPE_UNKNOWN;
  72     if (face_type)
  73         *face_type = DWRITE_FONT_FACE_TYPE_UNKNOWN;
  74     *font_count = 0;
  75
  76     if (DWRITE_MAKE_OPENTYPE_TAG(tag[0], tag[1], tag[2], tag[3]) == MS_TTCF_TAG)
  77     {
  78         const TTC_Header_V1 *header = font_data;
  79         *font_count = GET_BE_DWORD(header->numFonts);
  80         *file_type = DWRITE_FONT_FILE_TYPE_TRUETYPE_COLLECTION;
  81         if (face_type)
  82             *face_type = DWRITE_FONT_FACE_TYPE_TRUETYPE_COLLECTION;
  83         *supported = TRUE;
  84     }
  85     else if (GET_BE_DWORD(*(DWORD*)font_data) == 0x10000)
  86     {
  87         *font_count = 1;
  88         *file_type = DWRITE_FONT_FILE_TYPE_TRUETYPE;
  89         if (face_type)
  90             *face_type = DWRITE_FONT_FACE_TYPE_TRUETYPE;
  91         *supported = TRUE;
  92     }
  93     else if (DWRITE_MAKE_OPENTYPE_TAG(tag[0], tag[1], tag[2], tag[3]) == MS_OTTO_TAG)
  94     {
  95         *file_type = DWRITE_FONT_FILE_TYPE_CFF;
  96     }
  97     return S_OK;
  98 }
  99
 100 HRESULT find_font_table(IDWriteFontFileStream *stream, UINT32 font_index, UINT32 tag, const void** table_data, void** table_context, UINT32 *table_size, BOOL* found)
 101 {
 102     const CHAR *first_data;
 103     void *first_context;
 104     HRESULT hr;
 105     TTC_SFNT_V1 *font_header = NULL;
 106     void *sfnt_context;
 107     TT_TableRecord *table_record = NULL;
 108     void *table_record_context;
 109     int i;
 110     int table_count;
 111     int table_offset = 0;
 112
 113     *found = FALSE;
 114
 115     hr = IDWriteFontFileStream_ReadFileFragment(stream, (const void**)&first_data, 0, 4, &first_context);
 116     if (SUCCEEDED(hr))
 117     {
 118         if (DWRITE_MAKE_OPENTYPE_TAG(first_data[0], first_data[1], first_data[2], first_data[3]) == MS_TTCF_TAG)
 119         {
 120             const TTC_Header_V1 *ttc_header;
 121             void * ttc_context;
 122             hr = IDWriteFontFileStream_ReadFileFragment(stream, (const void**)&ttc_header, 0, sizeof(*ttc_header), &ttc_context);
 123             if (SUCCEEDED(hr))
 124             {
 125                 table_offset = GET_BE_DWORD(ttc_header->OffsetTable[0]);
 126                 if (font_index >= GET_BE_DWORD(ttc_header->numFonts))
 127                     hr = E_INVALIDARG;
 128                 else
 129                     hr = IDWriteFontFileStream_ReadFileFragment(stream, (const void**)&font_header, table_offset, sizeof(*font_header), &sfnt_context);
 130                 IDWriteFontFileStream_ReleaseFileFragment(stream, ttc_context);
 131             }
 132         }
 133         else
 134         {
 135             if (font_index > 0)
 136                 hr = E_INVALIDARG;
 137             else
 138                 hr = IDWriteFontFileStream_ReadFileFragment(stream, (const void**)&font_header, 0, sizeof(*font_header), &sfnt_context);
 139         }
 140         IDWriteFontFileStream_ReleaseFileFragment(stream, first_context);
 141     }
 142     if (FAILED(hr))
 143         return hr;
 144
 145     table_count = GET_BE_WORD(font_header->numTables);
 146     table_offset += sizeof(*font_header);
 147     for (i = 0; i < table_count; i++)
 148     {
 149         hr = IDWriteFontFileStream_ReadFileFragment(stream, (const void**)&table_record, table_offset, sizeof(*table_record), &table_record_context);
 150         if (FAILED(hr))
 151             break;
 152         if (DWRITE_MAKE_OPENTYPE_TAG(table_record->tag[0], table_record->tag[1], table_record->tag[2], table_record->tag[3]) == tag)
 153             break;
 154         IDWriteFontFileStream_ReleaseFileFragment(stream, table_record_context);
 155         table_offset += sizeof(*table_record);
 156     }
 157
 158     IDWriteFontFileStream_ReleaseFileFragment(stream, sfnt_context);
 159     if (SUCCEEDED(hr) && i < table_count)
 160     {
 161         int offset = GET_BE_DWORD(table_record->offset);
 162         int length = GET_BE_DWORD(table_record->length);
 163         IDWriteFontFileStream_ReleaseFileFragment(stream, table_record_context);
 164
 165         *found = TRUE;
 166         *table_size = length;
 167         hr = IDWriteFontFileStream_ReadFileFragment(stream, table_data, offset, length, table_context);
 168     }
 169
 170     return hr;
 171 }