ref: 9e422b67c8f1a2e06cb934c2867e0536729793f4
parent: 08dba4dc3555cbb90c7be59a31c413c26cfba503
author: Dominik Röttsches <drott@chromium.org>
date: Wed Dec 16 11:44:34 EST 2020
[sfnt] Add API to retrieve 'COLR' v1 root paint (#59703). * src/sfnt/ttcolr.c (BaseGlyphV1Record): New structure. (tt_face_load_colr): Handle version 1 table header. (find_base_glyph_v1_record): New auxiliary function. (tt_face_get_colr_glyph_paint): New function to find the root `FT_OpaquePaint` object for a given glyph ID. * src/sfnt/ttcolr.h: Updated.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
2020-12-16 Dominik Röttsches <drott@chromium.org>
+ [sfnt] Add API to retrieve 'COLR' v1 root paint (#59703).
+
+ * src/sfnt/ttcolr.c (BaseGlyphV1Record): New structure.
+ (tt_face_load_colr): Handle version 1 table header.
+ (find_base_glyph_v1_record): New auxiliary function.
+ (tt_face_get_colr_glyph_paint): New function to find the root
+ `FT_OpaquePaint` object for a given glyph ID.
+
+ * src/sfnt/ttcolr.h: Updated.
+
+2020-12-16 Dominik Röttsches <drott@chromium.org>
+
Add new methods required for 'COLR' v1 to public API (#59703).
* include/freetype/freetype.h (FT_Get_Color_Glyph_Paint): New method
--- a/src/sfnt/ttcolr.c
+++ b/src/sfnt/ttcolr.c
@@ -5,7 +5,7 @@
* TrueType and OpenType colored glyph layer support (body).
*
* Copyright (C) 2018-2020 by
- * David Turner, Robert Wilhelm, and Werner Lemberg.
+ * David Turner, Robert Wilhelm, Dominik Röttsches, and Werner Lemberg.
*
* Originally written by Shao Yu Zhang <shaozhang@fb.com>.
*
@@ -31,6 +31,7 @@
#include <freetype/internal/ftstream.h>
#include <freetype/tttags.h>
#include <freetype/ftcolor.h>
+#include <freetype/config/integer-types.h>
#ifdef TT_CONFIG_OPTION_COLOR_LAYERS
@@ -39,12 +40,16 @@
/* NOTE: These are the table sizes calculated through the specs. */
-#define BASE_GLYPH_SIZE 6U
-#define LAYER_SIZE 4U
-#define COLR_HEADER_SIZE 14U
+#define BASE_GLYPH_SIZE 6U
+#define BASE_GLYPH_V1_RECORD_SIZE 6U
+#define LAYER_V1_LIST_PAINT_OFFSET_SIZE 4U
+#define LAYER_V1_LIST_NUM_LAYERS_SIZE 4U
+#define COLOR_STOP_SIZE 6U
+#define LAYER_SIZE 4U
+#define COLR_HEADER_SIZE 14U
- typedef struct BaseGlyphRecord_
+ typedef struct BaseGlyphRecord_
{FT_UShort gid;
FT_UShort first_layer_index;
@@ -53,8 +58,17 @@
} BaseGlyphRecord;
- typedef struct Colr_
+ typedef struct BaseGlyphV1Record_
{+ FT_UShort gid;
+ /* Offset from start of BaseGlyphV1List, i.e., from base_glyphs_v1. */
+ FT_ULong paint_offset;
+
+ } BaseGlyphV1Record;
+
+
+ typedef struct Colr_
+ {FT_UShort version;
FT_UShort num_base_glyphs;
FT_UShort num_layers;
@@ -62,7 +76,14 @@
FT_Byte* base_glyphs;
FT_Byte* layers;
- /* The memory which backs up the `COLR' table. */
+ FT_ULong num_base_glyphs_v1;
+ /* Points at beginning of BaseGlyphV1List. */
+ FT_Byte* base_glyphs_v1;
+
+ FT_ULong num_layers_v1;
+ FT_Byte* layers_v1;
+
+ /* The memory that backs up the `COLR' table. */
void* table;
FT_ULong table_size;
@@ -88,10 +109,14 @@
FT_Byte* table = NULL;
FT_Byte* p = NULL;
+ /* Needed for reading array lengths in referenced tables. */
+ FT_Byte* p1 = NULL;
Colr* colr = NULL;
FT_ULong base_glyph_offset, layer_offset;
+ FT_ULong base_glyphs_offset_v1, num_base_glyphs_v1;
+ FT_ULong layer_offset_v1, num_layers_v1;
FT_ULong table_size;
@@ -115,7 +140,7 @@
goto NoColr;
colr->version = FT_NEXT_USHORT( p );
- if ( colr->version != 0 )
+ if ( colr->version != 0 && colr->version != 1 )
goto InvalidTable;
colr->num_base_glyphs = FT_NEXT_USHORT( p );
@@ -135,6 +160,35 @@
if ( colr->num_layers * LAYER_SIZE > table_size - layer_offset )
goto InvalidTable;
+ if ( colr->version == 1 )
+ {+ base_glyphs_offset_v1 = FT_NEXT_ULONG( p );
+
+ if ( base_glyphs_offset_v1 >= table_size )
+ goto InvalidTable;
+
+ p1 = (FT_Byte*)( table + base_glyphs_offset_v1 );
+ num_base_glyphs_v1 = FT_PEEK_ULONG( p1 );
+
+ if ( num_base_glyphs_v1 * BASE_GLYPH_V1_RECORD_SIZE >
+ table_size - base_glyphs_offset_v1 )
+ goto InvalidTable;
+
+ colr->num_base_glyphs_v1 = num_base_glyphs_v1;
+ colr->base_glyphs_v1 = p1;
+
+ layer_offset_v1 = FT_NEXT_ULONG( p );
+
+ if ( !layer_offset_v1 || layer_offset_v1 >= table_size )
+ goto InvalidTable;
+
+ p1 = (FT_Byte*)( table + layer_offset_v1 );
+ num_layers_v1 = FT_PEEK_ULONG( p1 );
+
+ colr->num_layers_v1 = num_layers_v1;
+ colr->layers_v1 = p1;
+ }
+
colr->base_glyphs = (FT_Byte*)( table + base_glyph_offset );
colr->layers = (FT_Byte*)( table + layer_offset );
colr->table = table;
@@ -260,6 +314,85 @@
return 0;
iterator->layer++;
+
+ return 1;
+ }
+
+
+ static FT_Bool
+ find_base_glyph_v1_record ( FT_Byte * base_glyph_begin,
+ FT_Int num_base_glyph,
+ FT_UInt glyph_id,
+ BaseGlyphV1Record *record )
+ {+ FT_Int min = 0;
+ FT_Int max = num_base_glyph - 1;
+
+
+ while ( min <= max )
+ {+ FT_Int mid = min + ( max - min ) / 2;
+
+ /*
+ * `base_glyph_begin` is the beginning of `BaseGlyphV1List`;
+ * skip `numBaseGlyphV1Records` by adding 4 to start binary search
+ * in the array of `BaseGlyphV1Record`.
+ */
+ FT_Byte *p = base_glyph_begin + 4 + mid * BASE_GLYPH_V1_RECORD_SIZE;
+
+ FT_UShort gid = FT_NEXT_USHORT( p );
+
+
+ if ( gid < glyph_id )
+ min = mid + 1;
+ else if (gid > glyph_id )
+ max = mid - 1;
+ else
+ {+ record->gid = gid;
+ record->paint_offset = FT_NEXT_ULONG ( p );
+ return 1;
+ }
+ }
+
+ return 0;
+ }
+
+
+ FT_LOCAL_DEF ( FT_Bool )
+ tt_face_get_colr_glyph_paint( TT_Face face,
+ FT_UInt base_glyph,
+ FT_OpaquePaint* opaque_paint )
+ {+ Colr* colr = (Colr*)face->colr;
+
+ BaseGlyphV1Record base_glyph_v1_record;
+ FT_Byte* p;
+
+
+ if ( colr->version < 1 || !colr->num_base_glyphs_v1 ||
+ !colr->base_glyphs_v1 )
+ return 0;
+
+ if ( opaque_paint->p )
+ return 0;
+
+ if ( !find_base_glyph_v1_record( colr->base_glyphs_v1,
+ colr->num_base_glyphs_v1,
+ base_glyph,
+ &base_glyph_v1_record ) )
+ return 0;
+
+ if ( !base_glyph_v1_record.paint_offset ||
+ base_glyph_v1_record.paint_offset > colr->table_size )
+ return 0;
+
+ p = (FT_Byte*)( colr->base_glyphs_v1 +
+ base_glyph_v1_record.paint_offset );
+ if ( p >= ( (FT_Byte*)colr->table + colr->table_size ) )
+ return 0;
+
+ opaque_paint->p = p;
return 1;
}
--- a/src/sfnt/ttcolr.h
+++ b/src/sfnt/ttcolr.h
@@ -42,6 +42,11 @@
FT_UInt *acolor_index,
FT_LayerIterator* iterator );
+ FT_LOCAL( FT_Bool )
+ tt_face_get_colr_glyph_paint( TT_Face face,
+ FT_UInt base_glyph,
+ FT_OpaquePaint* paint );
+
FT_LOCAL( FT_Error )
tt_face_colr_blend_layer( TT_Face face,
FT_UInt color_index,