ref: a3cfed5e87232c933bdc64f43e8ebebcfd18b41b
dir: /src/sfnt/ttcolr.c/
/***************************************************************************/
/* */
/* ttcolr.c */
/* */
/* TrueType and OpenType color outline support. */
/* */
/* Copyright 2018 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* Written by Shao Yu Zhang <[email protected]>. */
/* */
/* 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. */
/* */
/***************************************************************************/
/*************************************************************************/
/* */
/* `COLR' and `CPAL' table specification: */
/* */
/* https://www.microsoft.com/typography/otspec/colr.htm */
/* https://www.microsoft.com/typography/otspec/cpal.htm */
/* */
/*************************************************************************/
#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#ifdef TT_CONFIG_OPTION_COLOR_LAYERS
#include "ttcolr.h"
/* NOTE: These are the table sizes calculated through the specs. */
#define BASE_GLYPH_SIZE 6
#define LAYER_SIZE 4
#define COLR_HEADER_SIZE 14
#define CPAL_V0_HEADER_BASE_SIZE 12
#define COLOR_SIZE 4
typedef struct BaseGlyphRecord_
{
FT_UShort gid;
FT_UShort first_layer_index;
FT_UShort num_layers;
} BaseGlyphRecord;
typedef struct Colr_
{
FT_UShort version;
FT_UShort num_base_glyphs;
FT_UShort num_layers;
FT_Byte* base_glyphs;
FT_Byte* layers;
} Colr;
typedef struct Cpal_
{
FT_UShort version; /* Table version number (0 or 1 supported). */
FT_UShort num_palettes_entries; /* # of entries in each palette. */
FT_UShort num_palettes; /* # of palettes in the table. */
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. */
/* version 1 fields */
FT_ULong* palette_types;
FT_UShort* palette_labels;
FT_UShort* palette_entry_labels;
} Cpal;
typedef struct ColrCpal_
{
/* Accessors into the colr/cpal tables. */
Colr colr;
Cpal cpal;
/* The memory which backs up colr/cpal tables. */
void* colr_table;
void* cpal_table;
} ColrCpal;
/*************************************************************************/
/* */
/* 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 trace_ttcolrcpal
FT_LOCAL_DEF( FT_Error )
tt_face_load_colr( TT_Face face,
FT_Stream stream )
{
FT_Error error;
FT_Memory memory = face->root.memory;
FT_Byte* colr_table = NULL;
FT_Byte* cpal_table = NULL;
FT_Byte* p = NULL;
Colr colr;
Cpal cpal;
ColrCpal* cc = NULL;
FT_ULong base_glyph_begin, base_glyph_end, layer_begin, layer_end;
FT_ULong colors_begin, colors_end;
FT_ULong table_size;
face->colr_and_cpal = NULL;
error = face->goto_table( face, TTAG_COLR, stream, &table_size );
if ( error )
goto NoColor;
if ( table_size < sizeof ( COLR_HEADER_SIZE ) )
goto InvalidTable;
if ( FT_FRAME_EXTRACT( table_size, colr_table ) )
goto NoColor;
p = colr_table;
FT_ZERO( &colr );
colr.version = FT_NEXT_USHORT( p );
colr.num_base_glyphs = FT_NEXT_USHORT( p );
base_glyph_begin = FT_NEXT_ULONG( p );
layer_begin = FT_NEXT_ULONG( p );
colr.num_layers = FT_NEXT_USHORT( p );
colr.base_glyphs = (FT_Byte*)( colr_table + base_glyph_begin );
colr.layers = (FT_Byte*)( colr_table + layer_begin );
if ( colr.version != 0 )
goto InvalidTable;
/* Ensure variable length tables lies within the COLR table. */
/* We wrap around FT_ULong at most once since count is FT_UShort. */
base_glyph_end = base_glyph_begin +
colr.num_base_glyphs * BASE_GLYPH_SIZE;
layer_end = layer_begin +
colr.num_layers * LAYER_SIZE;
if ( base_glyph_end < base_glyph_begin || base_glyph_end > table_size ||
layer_end < layer_begin || layer_end > table_size )
goto InvalidTable;
/* Ensure pointers don't wrap. */
if ( colr.base_glyphs < colr_table || colr.layers < colr_table )
goto InvalidTable;
error = face->goto_table( face, TTAG_CPAL, stream, &table_size );
if ( error )
goto NoColor;
if ( table_size < CPAL_V0_HEADER_BASE_SIZE )
goto InvalidTable;
if ( FT_FRAME_EXTRACT( table_size, cpal_table ) )
goto NoColor;
p = cpal_table;
FT_ZERO( &cpal );
cpal.version = FT_NEXT_USHORT( p );
cpal.num_palettes_entries = FT_NEXT_USHORT( p );
cpal.num_palettes = FT_NEXT_USHORT( p );
cpal.num_colors = FT_NEXT_USHORT( p );
colors_begin = FT_NEXT_ULONG( p );
cpal.color_indices = p;
cpal.colors = (FT_Byte*)cpal_table + colors_begin;
if ( cpal.version != 0 && cpal.version != 1 )
goto InvalidTable;
colors_end = colors_begin + cpal.num_colors * COLOR_SIZE;
/* Ensure variable length tables lies within the COLR table. */
/* We wrap around FT_ULong at most once since count is FT_UShort. */
if ( colors_end < colors_begin || colors_end > table_size )
goto InvalidTable;
if ( cpal.colors < cpal_table )
goto InvalidTable;
if ( FT_NEW( cc ) )
goto NoColor;
cc->colr = colr;
cc->cpal = cpal;
cc->colr_table = colr_table;
cc->cpal_table = cpal_table;
face->colr_and_cpal = cc;
return FT_Err_Ok;
InvalidTable:
error = FT_THROW( Invalid_File_Format );
NoColor:
if ( colr_table )
FT_FRAME_RELEASE( colr_table );
if ( cpal_table )
FT_FRAME_RELEASE( cpal_table );
return error;
}
FT_LOCAL_DEF( void )
tt_face_free_colr( TT_Face face )
{
FT_Stream stream = face->root.stream;
FT_Memory memory = face->root.memory;
ColrCpal* colr_and_cpal = (ColrCpal*)face->colr_and_cpal;
if ( colr_and_cpal )
{
FT_FRAME_RELEASE( colr_and_cpal->colr_table );
FT_FRAME_RELEASE( colr_and_cpal->cpal_table );
FT_FREE( face->colr_and_cpal );
}
}
static FT_Bool
find_base_glyph_record( FT_Byte* base_glyph_begin,
FT_Int num_base_glyph,
FT_UInt glyph_id,
BaseGlyphRecord* record )
{
FT_Int min = 0;
FT_Int max = num_base_glyph - 1;
while ( min <= max )
{
FT_Int mid = min + ( max - min ) / 2;
FT_Byte* p = base_glyph_begin + mid * BASE_GLYPH_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->first_layer_index = FT_NEXT_USHORT( p );
record->num_layers = FT_NEXT_USHORT( p );
return 1;
}
}
return 0;
}
FT_LOCAL_DEF( FT_Error )
tt_face_load_colr_layers( TT_Face face,
FT_UInt glyph_id,
FT_Glyph_Layer *ret_layers,
FT_UShort* ret_num_layers )
{
FT_Error error;
FT_Memory memory = face->root.memory;
ColrCpal* colr_and_cpal = (ColrCpal *)face->colr_and_cpal;
Colr* colr = &colr_and_cpal->colr;
Cpal* cpal = &colr_and_cpal->cpal;
BaseGlyphRecord glyph_record;
FT_Glyph_Layer layers;
int layer_idx;
FT_Byte* layer_record_ptr;
if ( !ret_layers || !ret_num_layers )
return FT_THROW( Invalid_Argument );
if ( !find_base_glyph_record( colr->base_glyphs,
colr->num_base_glyphs,
glyph_id,
&glyph_record ) )
{
*ret_layers = NULL;
*ret_num_layers = 0;
return FT_Err_Ok;
}
/* Load all colors for the glyphs; this would be stored in the slot. */
layer_record_ptr = colr->layers +
glyph_record.first_layer_index * LAYER_SIZE;
if ( FT_NEW_ARRAY( layers, glyph_record.num_layers ) )
goto Error;
for ( layer_idx = 0; layer_idx < glyph_record.num_layers; layer_idx++ )
{
FT_UShort gid = FT_NEXT_USHORT( layer_record_ptr );
FT_UShort palette_index = FT_NEXT_USHORT( layer_record_ptr );
if ( palette_index != 0xFFFF &&
palette_index >= cpal->num_palettes_entries )
{
error = FT_THROW( Invalid_File_Format );
goto Error;
}
layers[layer_idx].color_index = palette_index;
layers[layer_idx].glyph_index = gid;
}
*ret_layers = layers;
*ret_num_layers = glyph_record.num_layers;
return FT_Err_Ok;
Error:
if ( layers )
FT_FREE( layers );
return error;
}
static FT_Bool
tt_face_find_color( TT_Face face,
FT_UInt color_index,
FT_Byte* blue,
FT_Byte* green,
FT_Byte* red,
FT_Byte* alpha )
{
ColrCpal* colr_and_cpal = (ColrCpal *)face->colr_and_cpal;
Cpal* cpal = &colr_and_cpal->cpal;
FT_Int palette_index = 0;
FT_Byte* p;
FT_Int color_offset;
if ( color_index >= cpal->num_palettes_entries )
return 0;
p = cpal->color_indices + palette_index * (int)sizeof ( FT_UShort );
color_offset = FT_NEXT_USHORT( p );
p = cpal->colors + color_offset + COLOR_SIZE * color_index;
*red = FT_NEXT_BYTE( p );
*green = FT_NEXT_BYTE( p );
*blue = FT_NEXT_BYTE( p );
*alpha = FT_NEXT_BYTE( p );
return 1;
}
FT_LOCAL_DEF( FT_Error )
tt_face_colr_blend_layer( TT_Face face,
FT_UInt color_index,
FT_GlyphSlot dstSlot,
FT_GlyphSlot srcSlot )
{
FT_Error error;
FT_UInt x, y;
FT_Byte b, g, r, alpha;
FT_ULong size;
FT_Byte* src;
FT_Byte* dst;
if ( !dstSlot->bitmap.buffer )
{
/* Initialize destination of color bitmap */
/* with the size of first component. */
dstSlot->bitmap_left = srcSlot->bitmap_left;
dstSlot->bitmap_top = srcSlot->bitmap_top;
dstSlot->bitmap.width = srcSlot->bitmap.width;
dstSlot->bitmap.rows = srcSlot->bitmap.rows;
dstSlot->bitmap.pixel_mode = FT_PIXEL_MODE_BGRA;
dstSlot->bitmap.pitch = (int)dstSlot->bitmap.width * 4;
dstSlot->bitmap.num_grays = 256;
size = dstSlot->bitmap.rows * (unsigned int)dstSlot->bitmap.pitch;
error = ft_glyphslot_alloc_bitmap( dstSlot, size );
if ( error )
return error;
FT_MEM_ZERO( dstSlot->bitmap.buffer, size );
}
else
{
/* Resize destination if needed such that new component fits. */
FT_Int x_min, x_max, y_min, y_max;
x_min = FT_MIN( dstSlot->bitmap_left, srcSlot->bitmap_left );
x_max = FT_MAX( dstSlot->bitmap_left + (FT_Int)dstSlot->bitmap.width,
srcSlot->bitmap_left + (FT_Int)srcSlot->bitmap.width );
y_min = FT_MIN( dstSlot->bitmap_top - (FT_Int)dstSlot->bitmap.rows,
srcSlot->bitmap_top - (FT_Int)srcSlot->bitmap.rows );
y_max = FT_MAX( dstSlot->bitmap_top, srcSlot->bitmap_top );
if ( x_min != dstSlot->bitmap_left ||
x_max != dstSlot->bitmap_left + (FT_Int)dstSlot->bitmap.width ||
y_min != dstSlot->bitmap_top - (FT_Int)dstSlot->bitmap.rows ||
y_max != dstSlot->bitmap_top )
{
FT_Memory memory = face->root.memory;
FT_UInt width = (FT_UInt)( x_max - x_min );
FT_UInt rows = (FT_UInt)( y_max - y_min );
FT_UInt pitch = width * 4;
FT_Byte* buf;
FT_Byte* p;
FT_Byte* q;
size = rows * pitch;
if ( FT_ALLOC( buf, size ) )
return error;
p = dstSlot->bitmap.buffer;
q = buf +
(int)pitch * ( y_max - dstSlot->bitmap_top ) +
4 * ( dstSlot->bitmap_left - x_min );
for ( y = 0; y < dstSlot->bitmap.rows; y++ )
{
FT_MEM_COPY( q, p, dstSlot->bitmap.width * 4 );
p += dstSlot->bitmap.pitch;
q += pitch;
}
ft_glyphslot_set_bitmap( dstSlot, buf );
dstSlot->bitmap_top = y_max;
dstSlot->bitmap_left = x_min;
dstSlot->bitmap.width = width;
dstSlot->bitmap.rows = rows;
dstSlot->bitmap.pitch = (int)pitch;
dstSlot->internal->flags |= FT_GLYPH_OWN_BITMAP;
dstSlot->format = FT_GLYPH_FORMAT_BITMAP;
}
}
/* Default assignments to pacify compiler. */
r = g = b = 0;
alpha = 255;
if ( color_index != 0xFFFF )
tt_face_find_color( face, color_index, &b, &g, &r, &alpha );
else
{
/* TODO. foreground color from argument? */
/* Add public FT_Render_Glyph_Color() with color value? */
}
/* XXX Convert if srcSlot.bitmap is not grey? */
src = srcSlot->bitmap.buffer;
dst = dstSlot->bitmap.buffer +
dstSlot->bitmap.pitch * ( dstSlot->bitmap_top - srcSlot->bitmap_top ) +
4 * ( srcSlot->bitmap_left - dstSlot->bitmap_left );
for ( y = 0; y < srcSlot->bitmap.rows; y++ )
{
for ( x = 0; x < srcSlot->bitmap.width; x++ )
{
int aa = src[x];
int fa = alpha * aa / 255;
int fb = b * fa / 255;
int fg = g * fa / 255;
int fr = r * fa / 255;
int ba2 = 255 - fa;
int bb = dst[4 * x + 0];
int bg = dst[4 * x + 1];
int br = dst[4 * x + 2];
int ba = dst[4 * x + 3];
dst[4 * x + 0] = (FT_Byte)( bb * ba2 / 255 + fb );
dst[4 * x + 1] = (FT_Byte)( bg * ba2 / 255 + fg );
dst[4 * x + 2] = (FT_Byte)( br * ba2 / 255 + fr );
dst[4 * x + 3] = (FT_Byte)( ba * ba2 / 255 + fa );
}
src += srcSlot->bitmap.pitch;
dst += dstSlot->bitmap.pitch;
}
return FT_Err_Ok;
}
#else /* !TT_CONFIG_OPTION_COLOR_LAYERS */
/* ANSI C doesn't like empty source files */
typedef int _tt_colr_dummy;
#endif /* !TT_CONFIG_OPTION_COLOR_LAYERS */
/* EOF */