ref: b7c467b6efa5a91945854de81632be45d6f360ff
dir: /src/sfnt/ttcpal.c/
/****************************************************************************
*
* ttcpal.c
*
* TrueType and OpenType color palette support (body).
*
* Copyright (C) 2018-2020 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* Originally written by Shao Yu Zhang <shaozhang@fb.com>.
*
* 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.
*
*/
/**************************************************************************
*
* `CPAL' table specification:
*
* https://www.microsoft.com/typography/otspec/cpal.htm
*
*/
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftstream.h>
#include <freetype/tttags.h>
#include <freetype/ftcolor.h>
#ifdef TT_CONFIG_OPTION_COLOR_LAYERS
#include "ttcpal.h"
/* NOTE: These are the table sizes calculated through the specs. */
#define CPAL_V0_HEADER_BASE_SIZE 12
#define COLOR_SIZE 4
/* all data from `CPAL' not covered in FT_Palette_Data */
typedef struct Cpal_
{
FT_UShort version; /* Table version number (0 or 1 supported). */
FT_UShort num_colors; /* Total number of color records, */
/* combined for all palettes. */
FT_Byte* colors; /* RGBA array of colors */
FT_Byte* color_indices; /* Index of each palette's first color record */
/* in the combined color record array. */
/* The memory which backs up the `CPAL' table. */
void* table;
FT_ULong table_size;
} Cpal;
/**************************************************************************
*
* The macro FT_COMPONENT is used in trace mode. It is an implicit
* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
* messages during execution.
*/
#undef FT_COMPONENT
#define FT_COMPONENT ttcpal
FT_LOCAL_DEF( FT_Error )
tt_face_load_cpal( TT_Face face,
FT_Stream stream )
{
FT_Error error;
FT_Memory memory = face->root.memory;
FT_Byte* table = NULL;
FT_Byte* p = NULL;
Cpal* cpal = NULL;
FT_ULong colors_offset;
FT_ULong table_size;
error = face->goto_table( face, TTAG_CPAL, stream, &table_size );
if ( error )
goto NoCpal;
if ( table_size < CPAL_V0_HEADER_BASE_SIZE )
goto InvalidTable;
if ( FT_FRAME_EXTRACT( table_size, table ) )
goto NoCpal;
p = table;
if ( FT_NEW( cpal ) )
goto NoCpal;
cpal->version = FT_NEXT_USHORT( p );
if ( cpal->version > 1 )
goto InvalidTable;
face->palette_data.num_palette_entries = FT_NEXT_USHORT( p );
face->palette_data.num_palettes = FT_NEXT_USHORT( p );
cpal->num_colors = FT_NEXT_USHORT( p );
colors_offset = FT_NEXT_ULONG( p );
if ( CPAL_V0_HEADER_BASE_SIZE +
face->palette_data.num_palettes * 2U > table_size )
goto InvalidTable;
if ( colors_offset >= table_size )
goto InvalidTable;
if ( cpal->num_colors * COLOR_SIZE > table_size - colors_offset )
goto InvalidTable;
if ( face->palette_data.num_palette_entries > cpal->num_colors )
goto InvalidTable;
cpal->color_indices = p;
cpal->colors = (FT_Byte*)( table + colors_offset );
if ( cpal->version == 1 )
{
FT_ULong type_offset, label_offset, entry_label_offset;
FT_UShort* array = NULL;
FT_UShort* limit;
FT_UShort* q;
if ( CPAL_V0_HEADER_BASE_SIZE +
face->palette_data.num_palettes * 2U +
3U * 4 > table_size )
goto InvalidTable;
p += face->palette_data.num_palettes * 2;
type_offset = FT_NEXT_ULONG( p );
label_offset = FT_NEXT_ULONG( p );
entry_label_offset = FT_NEXT_ULONG( p );
if ( type_offset )
{
if ( type_offset >= table_size )
goto InvalidTable;
if ( face->palette_data.num_palettes * 2 >
table_size - type_offset )
goto InvalidTable;
if ( FT_QNEW_ARRAY( array, face->palette_data.num_palettes ) )
goto NoCpal;
p = table + type_offset;
q = array;
limit = q + face->palette_data.num_palettes;
while ( q < limit )
*q++ = FT_NEXT_USHORT( p );
face->palette_data.palette_flags = array;
}
if ( label_offset )
{
if ( label_offset >= table_size )
goto InvalidTable;
if ( face->palette_data.num_palettes * 2 >
table_size - label_offset )
goto InvalidTable;
if ( FT_QNEW_ARRAY( array, face->palette_data.num_palettes ) )
goto NoCpal;
p = table + label_offset;
q = array;
limit = q + face->palette_data.num_palettes;
while ( q < limit )
*q++ = FT_NEXT_USHORT( p );
face->palette_data.palette_name_ids = array;
}
if ( entry_label_offset )
{
if ( entry_label_offset >= table_size )
goto InvalidTable;
if ( face->palette_data.num_palette_entries * 2 >
table_size - entry_label_offset )
goto InvalidTable;
if ( FT_QNEW_ARRAY( array, face->palette_data.num_palette_entries ) )
goto NoCpal;
p = table + entry_label_offset;
q = array;
limit = q + face->palette_data.num_palette_entries;
while ( q < limit )
*q++ = FT_NEXT_USHORT( p );
face->palette_data.palette_entry_name_ids = array;
}
}
cpal->table = table;
cpal->table_size = table_size;
face->cpal = cpal;
/* set up default palette */
if ( FT_NEW_ARRAY( face->palette,
face->palette_data.num_palette_entries ) )
goto NoCpal;
if ( tt_face_palette_set( face, 0 ) )
goto InvalidTable;
return FT_Err_Ok;
InvalidTable:
error = FT_THROW( Invalid_Table );
NoCpal:
FT_FRAME_RELEASE( table );
FT_FREE( cpal );
face->cpal = NULL;
/* arrays in `face->palette_data' and `face->palette' */
/* are freed in `sfnt_done_face' */
return error;
}
FT_LOCAL_DEF( void )
tt_face_free_cpal( TT_Face face )
{
FT_Stream stream = face->root.stream;
FT_Memory memory = face->root.memory;
Cpal* cpal = (Cpal*)face->cpal;
if ( cpal )
{
FT_FRAME_RELEASE( cpal->table );
FT_FREE( cpal );
}
}
FT_LOCAL_DEF( FT_Error )
tt_face_palette_set( TT_Face face,
FT_UInt palette_index )
{
Cpal* cpal = (Cpal*)face->cpal;
FT_Byte* offset;
FT_Byte* p;
FT_Color* q;
FT_Color* limit;
FT_UShort color_index;
if ( !cpal || palette_index >= face->palette_data.num_palettes )
return FT_THROW( Invalid_Argument );
offset = cpal->color_indices + 2 * palette_index;
color_index = FT_PEEK_USHORT( offset );
if ( color_index + face->palette_data.num_palette_entries >
cpal->num_colors )
return FT_THROW( Invalid_Table );
p = cpal->colors + COLOR_SIZE * color_index;
q = face->palette;
limit = q + face->palette_data.num_palette_entries;
while ( q < limit )
{
q->blue = FT_NEXT_BYTE( p );
q->green = FT_NEXT_BYTE( p );
q->red = FT_NEXT_BYTE( p );
q->alpha = FT_NEXT_BYTE( p );
q++;
}
return FT_Err_Ok;
}
#else /* !TT_CONFIG_OPTION_COLOR_LAYERS */
/* ANSI C doesn't like empty source files */
typedef int _tt_cpal_dummy;
#endif /* !TT_CONFIG_OPTION_COLOR_LAYERS */
/* EOF */