* include/freetype/config/ftheader.h (FT_OTSVG_H): New macro. * include/freetype/freetype.h (FT_FACE_FLAG_SVG, FT_HAS_SVG): New macros. (FT_LOAD_SVG_ONLY): New internal macro. * include/freetype/ftimage.h (FT_Glyph_Format): New enumeration value `FT_GLYPH_FORMAT_SVG`. * include/freetype/internal/ftobjs.h (FT_GLYPH_OWN_GZIP_SVG): New macro. * include/freetype/internal/fttrace.h: Add `ttsvg` for `ttsvg.c`. * include/freetype/internal/sfnt.h(load_svg, free_svg, load_svg_doc): New functions. * include/freetype/internal/tttypes.h (TT_FaceRec): Add `svg` for the SVG table. * include/freetype/otsvg.h (FT_SVG_DocumentRec): New structure to hold the SVG document and other necessary information of an OT-SVG glyph in a glyph slot. * include/freetype/tttags.h (TTAG_SVG): New macro. * src/base/ftobjs.c: Include `otsvg.h`. (ft_glyphslot_init): Allocate `FT_SVG_DocumentRec` in `slot->other` if the SVG table exists. (ft_glyphslot_clear): Free it upon clean-up if it is a GZIP compressed glyph. (ft_glyphslot_done): Free the document data if it is a GZIP compressed glyph. (FT_Load_Glyph): Don't auto-hint SVG documents. * src/cache/ftcbasic.c (ftc_basic_family_load_glyph): Add support for FT_GLYPH_FORMAT_SVG. * src/sfnt/rules.mk (SFNT_DRV_SRC): Add `ttsvg.c`. * src/sfnt/sfdriver.c: Include `ttsvg.h`. (sfnt_interface): Add `tt_face_load_svg`, `tt_face_free_svg` and `tt_face_load_svg_doc`. * src/sfnt/sfnt.c: Include `ttsvg.c`. * src/sfnt/sfobjs.c (sfnt_load_face, sfnt_done_face): Add code to load and free data of the the SVG table. * src/sfnt/ttsvg.c: New file, implementing `tt_face_load_svg`, `tt_face_free_svg` and `tt_face_load_svg_doc`. * src/sfnt/ttsvg.h: Declarations of the SVG functions in `ttsvg.c`.fix-sdf-squared-distances
Moazin Khatti
3 years ago
committed by
Werner Lemberg
parent
06c1a25e63
commit
f93a897afe
18 changed files with 741 additions and 24 deletions
@ -0,0 +1,114 @@ |
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/****************************************************************************
|
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* |
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* otsvg.h |
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* |
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* Interface for OT-SVG support related things (specification). |
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* |
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* Copyright (C) 2022 by |
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* David Turner, Robert Wilhelm, Werner Lemberg, and Moazin Khatti. |
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* |
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* This file is part of the FreeType project, and may only be used, |
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* modified, and distributed under the terms of the FreeType project |
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* license, LICENSE.TXT. By continuing to use, modify, or distribute |
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* this file you indicate that you have read the license and |
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* understand and accept it fully. |
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* |
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*/ |
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|
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|
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#ifndef OTSVG_H_ |
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#define OTSVG_H_ |
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#include <freetype/freetype.h> |
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#ifdef FREETYPE_H |
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#error "freetype.h of FreeType 1 has been loaded!" |
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#error "Please fix the directory search order for header files" |
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#error "so that freetype.h of FreeType 2 is found first." |
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#endif |
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FT_BEGIN_HEADER |
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/**************************************************************************
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* |
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* @struct: |
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* FT_SVG_DocumentRec_ |
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* |
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* @description: |
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* A structure that models one SVG document. |
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* |
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* @fields: |
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* svg_document :: |
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* A pointer to the SVG document. |
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* |
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* svg_document_length :: |
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* The length of `svg_document`. |
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* |
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* metrics :: |
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* A metrics object storing the size information. |
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* |
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* units_per_EM :: |
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* The size of the EM square. |
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* |
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* start_glyph_id :: |
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* The first glyph ID in the glyph range covered by this document. |
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* |
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* end_glyph_id :: |
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* The last glyph ID in the glyph range covered by this document. |
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* |
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* transform :: |
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* A 2x2 transformation matrix to apply to the glyph while rendering |
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* it. |
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* |
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* delta :: |
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* The translation to apply to the glyph while rendering. |
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* |
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* @note: |
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* When the slot is passed down to a renderer, the renderer can only |
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* access the `metrics` and `units_per_EM` fields via `slot->face`. |
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* However, when `FT_Glyph_To_Bitmap` sets up a dummy object, it has no |
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* way to set a `face` object. Thus, metrics information and |
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* `units_per_EM` (which is necessary for OT-SVG) has to be stored |
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* separately. |
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* |
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* @since: |
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* 2.12 |
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*/ |
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typedef struct FT_SVG_DocumentRec_ |
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{ |
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FT_Byte* svg_document; |
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FT_ULong svg_document_length; |
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FT_Size_Metrics metrics; |
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FT_UShort units_per_EM; |
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FT_UShort start_glyph_id; |
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FT_UShort end_glyph_id; |
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FT_Matrix transform; |
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FT_Vector delta; |
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} FT_SVG_DocumentRec; |
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/**************************************************************************
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* |
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* @type: |
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* FT_SVG_Document |
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* |
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* @description: |
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* A handle to an @FT_SVG_DocumentRec object. |
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* |
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* @since: |
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* 2.12 |
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*/ |
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typedef struct FT_SVG_DocumentRec_* FT_SVG_Document; |
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FT_END_HEADER |
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#endif /* OTSVG_H_ */ |
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/* END */ |
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@ -0,0 +1,386 @@ |
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/****************************************************************************
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* |
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* ttsvg.c |
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* |
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* OpenType SVG Color (specification). |
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* |
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* Copyright (C) 2022 by |
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* David Turner, Robert Wilhelm, Werner Lemberg, and Moazin Khatti. |
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* |
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* This file is part of the FreeType project, and may only be used, |
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* modified, and distributed under the terms of the FreeType project |
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* license, LICENSE.TXT. By continuing to use, modify, or distribute |
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* this file you indicate that you have read the license and |
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* understand and accept it fully. |
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* |
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*/ |
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|
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|
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/**************************************************************************
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* |
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* 'SVG' table specification: |
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* |
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* https://docs.microsoft.com/en-us/typography/opentype/spec/svg
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* |
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*/ |
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#include <ft2build.h> |
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#include <freetype/internal/ftstream.h> |
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#include <freetype/internal/ftobjs.h> |
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#include <freetype/internal/ftdebug.h> |
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#include <freetype/tttags.h> |
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#include <freetype/ftgzip.h> |
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#include <freetype/otsvg.h> |
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#ifdef FT_CONFIG_OPTION_SVG |
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#include "ttsvg.h" |
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typedef struct Svg_ |
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{ |
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FT_UShort version; /* table version (starting at 0) */ |
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FT_UShort num_entries; /* number of SVG document records */ |
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FT_Byte* svg_doc_list; /* pointer to the start of SVG Document List */ |
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void* table; /* memory that backs up SVG */ |
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FT_ULong table_size; |
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} Svg; |
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/**************************************************************************
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* |
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* The macro FT_COMPONENT is used in trace mode. It is an implicit |
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* parameter of the FT_TRACE() and FT_ERROR() macros, usued to print/log |
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* messages during execution. |
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*/ |
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#undef FT_COMPONENT |
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#define FT_COMPONENT ttsvg |
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FT_LOCAL_DEF( FT_Error ) |
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tt_face_load_svg( TT_Face face, |
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FT_Stream stream ) |
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{ |
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FT_Error error; |
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FT_Memory memory = face->root.memory; |
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FT_ULong table_size; |
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FT_Byte* table = NULL; |
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FT_Byte* p = NULL; |
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Svg* svg = NULL; |
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FT_ULong offsetToSVGDocumentList; |
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error = face->goto_table( face, TTAG_SVG, stream, &table_size ); |
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if ( error ) |
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goto NoSVG; |
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if ( FT_FRAME_EXTRACT( table_size, table ) ) |
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goto NoSVG; |
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/* Allocate memory for the SVG object */ |
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if ( FT_NEW( svg ) ) |
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goto NoSVG; |
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p = table; |
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svg->version = FT_NEXT_USHORT( p ); |
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offsetToSVGDocumentList = FT_NEXT_ULONG( p ); |
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if ( offsetToSVGDocumentList == 0 ) |
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goto InvalidTable; |
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svg->svg_doc_list = (FT_Byte*)( table + offsetToSVGDocumentList ); |
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p = svg->svg_doc_list; |
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svg->num_entries = FT_NEXT_USHORT( p ); |
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FT_TRACE3(( "version: %d\n", svg->version )); |
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FT_TRACE3(( "number of entries: %d\n", svg->num_entries )); |
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svg->table = table; |
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svg->table_size = table_size; |
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face->svg = svg; |
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face->root.face_flags |= FT_FACE_FLAG_SVG; |
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return FT_Err_Ok; |
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InvalidTable: |
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error = FT_THROW( Invalid_Table ); |
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NoSVG: |
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FT_FRAME_RELEASE( table ); |
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FT_FREE( svg ); |
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face->svg = NULL; |
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return error; |
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} |
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FT_LOCAL_DEF( void ) |
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tt_face_free_svg( TT_Face face ) |
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{ |
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FT_Memory memory = face->root.memory; |
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FT_Stream stream = face->root.stream; |
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Svg* svg = (Svg*)face->svg; |
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if ( svg ) |
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{ |
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FT_FRAME_RELEASE( svg->table ); |
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FT_FREE( svg ); |
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} |
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} |
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typedef struct Svg_doc_ |
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{ |
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FT_UShort start_glyph_id; |
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FT_UShort end_glyph_id; |
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FT_ULong offset; |
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FT_ULong length; |
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} Svg_doc; |
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static Svg_doc |
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extract_svg_doc( FT_Byte* stream ) |
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{ |
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Svg_doc doc; |
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doc.start_glyph_id = FT_NEXT_USHORT( stream ); |
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doc.end_glyph_id = FT_NEXT_USHORT( stream ); |
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doc.offset = FT_NEXT_ULONG( stream ); |
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doc.length = FT_NEXT_ULONG( stream ); |
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return doc; |
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} |
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static FT_Int |
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compare_svg_doc( Svg_doc doc, |
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FT_UInt glyph_index ) |
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{ |
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if ( glyph_index < doc.start_glyph_id ) |
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return -1; |
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else if ( glyph_index > doc.end_glyph_id ) |
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return 1; |
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else |
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return 0; |
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} |
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static FT_Error |
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find_doc( FT_Byte* stream, |
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FT_UShort num_entries, |
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FT_UInt glyph_index, |
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FT_ULong *doc_offset, |
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FT_ULong *doc_length, |
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FT_UShort *start_glyph, |
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FT_UShort *end_glyph ) |
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{ |
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FT_Error error; |
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Svg_doc start_doc; |
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Svg_doc mid_doc; |
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Svg_doc end_doc; |
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FT_Bool found = FALSE; |
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FT_UInt i = 0; |
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FT_UInt start_index = 0; |
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FT_UInt end_index = num_entries - 1; |
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FT_Int comp_res; |
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/* search algorithm */ |
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if ( num_entries == 0 ) |
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{ |
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error = FT_THROW( Invalid_Table ); |
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return error; |
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} |
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start_doc = extract_svg_doc( stream + start_index * 12 ); |
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end_doc = extract_svg_doc( stream + end_index * 12 ); |
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if ( ( compare_svg_doc( start_doc, glyph_index ) == -1 ) || |
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( compare_svg_doc( end_doc, glyph_index ) == 1 ) ) |
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{ |
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error = FT_THROW( Invalid_Glyph_Index ); |
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return error; |
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} |
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while ( start_index <= end_index ) |
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{ |
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i = ( start_index + end_index ) / 2; |
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mid_doc = extract_svg_doc( stream + i * 12 ); |
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comp_res = compare_svg_doc( mid_doc, glyph_index ); |
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if ( comp_res == 1 ) |
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{ |
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start_index = i + 1; |
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start_doc = extract_svg_doc( stream + start_index * 4 ); |
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} |
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else if ( comp_res == -1 ) |
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{ |
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end_index = i - 1; |
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end_doc = extract_svg_doc( stream + end_index * 4 ); |
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} |
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else |
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{ |
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found = TRUE; |
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break; |
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} |
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} |
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/* search algorithm end */ |
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if ( found != TRUE ) |
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{ |
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FT_TRACE5(( "SVG glyph not found\n" )); |
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error = FT_THROW( Invalid_Glyph_Index ); |
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} |
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else |
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{ |
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*doc_offset = mid_doc.offset; |
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*doc_length = mid_doc.length; |
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*start_glyph = mid_doc.start_glyph_id; |
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*end_glyph = mid_doc.end_glyph_id; |
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error = FT_Err_Ok; |
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} |
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return error; |
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} |
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FT_LOCAL_DEF( FT_Error ) |
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tt_face_load_svg_doc( FT_GlyphSlot glyph, |
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FT_UInt glyph_index ) |
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{ |
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FT_Byte* doc_list; /* pointer to the SVG doc list */ |
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FT_UShort num_entries; /* total number of entries in doc list */ |
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FT_ULong doc_offset; |
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FT_ULong doc_length; |
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FT_UShort start_glyph_id; |
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FT_UShort end_glyph_id; |
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FT_Error error = FT_Err_Ok; |
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TT_Face face = (TT_Face)glyph->face; |
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FT_Memory memory = face->root.memory; |
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Svg* svg = (Svg*)face->svg; |
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FT_SVG_Document svg_document = (FT_SVG_Document)glyph->other; |
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FT_ASSERT( !( svg == NULL ) ); |
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doc_list = svg->svg_doc_list; |
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num_entries = FT_NEXT_USHORT( doc_list ); |
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error = find_doc( doc_list, num_entries, glyph_index, |
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&doc_offset, &doc_length, |
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&start_glyph_id, &end_glyph_id ); |
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if ( error != FT_Err_Ok ) |
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goto Exit; |
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doc_list = svg->svg_doc_list; /* reset, so we can use it again */ |
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doc_list = (FT_Byte*)( doc_list + doc_offset ); |
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if ( ( doc_list[0] == 0x1F ) && ( doc_list[1] == 0x8B ) |
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&& ( doc_list[2] == 0x08 ) ) |
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{ |
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#ifdef FT_CONFIG_OPTION_SYSTEM_ZLIB |
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|
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FT_ULong uncomp_size; |
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FT_Byte* uncomp_buffer; |
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|
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|
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/*
|
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* Get the size of the original document. This helps in allotting the |
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* buffer to accommodate the uncompressed version. The last 4 bytes |
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* of the compressed document are equal to the original size modulo |
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* 2^32. Since the size of SVG documents is less than 2^32 bytes we |
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* can use this accurately. The four bytes are stored in |
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* little-endian format. |
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*/ |
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FT_TRACE4(( "SVG document is GZIP compressed\n" )); |
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uncomp_size = (FT_ULong)doc_list[doc_length - 1] << 24 | |
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(FT_ULong)doc_list[doc_length - 2] << 16 | |
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(FT_ULong)doc_list[doc_length - 3] << 8 | |
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(FT_ULong)doc_list[doc_length - 4]; |
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|
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if ( FT_QALLOC( uncomp_buffer, uncomp_size ) ) |
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goto Exit; |
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|
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error = FT_Gzip_Uncompress( memory, |
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uncomp_buffer, |
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&uncomp_size, |
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doc_list, |
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doc_length ); |
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if ( error ) |
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{ |
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FT_FREE( uncomp_buffer ); |
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error = FT_THROW( Invalid_Table ); |
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goto Exit; |
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} |
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|
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glyph->internal->flags |= FT_GLYPH_OWN_GZIP_SVG; |
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|
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doc_list = uncomp_buffer; |
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doc_length = uncomp_size; |
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|
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#else /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */ |
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|
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error = FT_THROW( Unimplemented_Feature ); |
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goto Exit; |
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|
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#endif /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */ |
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} |
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|
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svg_document->svg_document = doc_list; |
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svg_document->svg_document_length = doc_length; |
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|
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svg_document->metrics = glyph->face->size->metrics; |
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svg_document->units_per_EM = glyph->face->units_per_EM; |
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|
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svg_document->start_glyph_id = start_glyph_id; |
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svg_document->end_glyph_id = end_glyph_id; |
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|
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svg_document->transform.xx = 0x10000; |
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svg_document->transform.xy = 0; |
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svg_document->transform.yx = 0; |
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svg_document->transform.yy = 0x10000; |
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|
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svg_document->delta.x = 0; |
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svg_document->delta.y = 0; |
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|
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FT_TRACE5(( "start_glyph_id: %d\n", start_glyph_id )); |
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FT_TRACE5(( "end_glyph_id: %d\n", end_glyph_id )); |
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FT_TRACE5(( "svg_document:\n" )); |
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FT_TRACE5(( " %.*s\n", (FT_UInt)doc_length, doc_list )); |
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|
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glyph->other = svg_document; |
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|
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Exit: |
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return error; |
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} |
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|
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#else /* !FT_CONFIG_OPTION_SVG */ |
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|
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/* ANSI C doesn't like empty source files */ |
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typedef int _tt_svg_dummy; |
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|
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#endif /* !FT_CONFIG_OPTION_SVG */ |
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|
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|
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/* END */ |
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@ -0,0 +1,43 @@ |
||||
/****************************************************************************
|
||||
* |
||||
* ttsvg.h |
||||
* |
||||
* OpenType SVG Color (specification). |
||||
* |
||||
* Copyright (C) 2022 by |
||||
* David Turner, Robert Wilhelm, Werner Lemberg, and Moazin Khatti. |
||||
* |
||||
* This file is part of the FreeType project, and may only be used, |
||||
* modified, and distributed under the terms of the FreeType project |
||||
* license, LICENSE.TXT. By continuing to use, modify, or distribute |
||||
* this file you indicate that you have read the license and |
||||
* understand and accept it fully. |
||||
* |
||||
*/ |
||||
|
||||
#ifndef TTSVG_H_ |
||||
#define TTSVG_H_ |
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|
||||
#include <freetype/internal/ftstream.h> |
||||
#include <freetype/internal/tttypes.h> |
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|
||||
|
||||
FT_BEGIN_HEADER |
||||
|
||||
FT_LOCAL( FT_Error ) |
||||
tt_face_load_svg( TT_Face face, |
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FT_Stream stream ); |
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|
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FT_LOCAL( void ) |
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tt_face_free_svg( TT_Face face ); |
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|
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FT_LOCAL( FT_Error ) |
||||
tt_face_load_svg_doc( FT_GlyphSlot glyph, |
||||
FT_UInt glyph_index ); |
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|
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FT_END_HEADER |
||||
|
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#endif /* TTSVG_H_ */ |
||||
|
||||
|
||||
/* END */ |
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