Edit
kc3-lang/freetype/src/sfnt/ttcolr.c
Werner Lemberg
- src/sfnt/ttcolr.c
-
/**************************************************************************** * * ttcolr.c * * TrueType and OpenType colored glyph layer 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. * */ /************************************************************************** * * `COLR' table specification: * * https://www.microsoft.com/typography/otspec/colr.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 "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 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; /* The memory which backs up the `COLR' table. */ void* table; FT_ULong table_size; } Colr; /************************************************************************** * * 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 ttcolr 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* table = NULL; FT_Byte* p = NULL; Colr* colr = NULL; FT_ULong base_glyph_offset, layer_offset; FT_ULong table_size; /* `COLR' always needs `CPAL' */ if ( !face->cpal ) return FT_THROW( Invalid_File_Format ); error = face->goto_table( face, TTAG_COLR, stream, &table_size ); if ( error ) goto NoColr; if ( table_size < COLR_HEADER_SIZE ) goto InvalidTable; if ( FT_FRAME_EXTRACT( table_size, table ) ) goto NoColr; p = table; if ( FT_NEW( colr ) ) goto NoColr; colr->version = FT_NEXT_USHORT( p ); if ( colr->version != 0 ) goto InvalidTable; colr->num_base_glyphs = FT_NEXT_USHORT( p ); base_glyph_offset = FT_NEXT_ULONG( p ); if ( base_glyph_offset >= table_size ) goto InvalidTable; if ( colr->num_base_glyphs * BASE_GLYPH_SIZE > table_size - base_glyph_offset ) goto InvalidTable; layer_offset = FT_NEXT_ULONG( p ); colr->num_layers = FT_NEXT_USHORT( p ); if ( layer_offset >= table_size ) goto InvalidTable; if ( colr->num_layers * LAYER_SIZE > table_size - layer_offset ) goto InvalidTable; colr->base_glyphs = (FT_Byte*)( table + base_glyph_offset ); colr->layers = (FT_Byte*)( table + layer_offset ); colr->table = table; colr->table_size = table_size; face->colr = colr; return FT_Err_Ok; InvalidTable: error = FT_THROW( Invalid_Table ); NoColr: FT_FRAME_RELEASE( table ); FT_FREE( colr ); 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; Colr* colr = (Colr*)face->colr; if ( colr ) { FT_FRAME_RELEASE( colr->table ); FT_FREE( colr ); } } 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_Bool ) tt_face_get_colr_layer( TT_Face face, FT_UInt base_glyph, FT_UInt *aglyph_index, FT_UInt *acolor_index, FT_LayerIterator* iterator ) { Colr* colr = (Colr*)face->colr; BaseGlyphRecord glyph_record; if ( !colr ) return 0; if ( !iterator->p ) { FT_ULong offset; /* first call to function */ iterator->layer = 0; if ( !find_base_glyph_record( colr->base_glyphs, colr->num_base_glyphs, base_glyph, &glyph_record ) ) return 0; if ( glyph_record.num_layers ) iterator->num_layers = glyph_record.num_layers; else return 0; offset = LAYER_SIZE * glyph_record.first_layer_index; if ( offset + LAYER_SIZE * glyph_record.num_layers > colr->table_size ) return 0; iterator->p = colr->layers + offset; } if ( iterator->layer >= iterator->num_layers ) return 0; *aglyph_index = FT_NEXT_USHORT( iterator->p ); *acolor_index = FT_NEXT_USHORT( iterator->p ); if ( *aglyph_index >= (FT_UInt)( FT_FACE( face )->num_glyphs ) || ( *acolor_index != 0xFFFF && *acolor_index >= face->palette_data.num_palette_entries ) ) return 0; iterator->layer++; 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 = NULL; 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; } } if ( color_index == 0xFFFF ) { if ( face->have_foreground_color ) { b = face->foreground_color.blue; g = face->foreground_color.green; r = face->foreground_color.red; alpha = face->foreground_color.alpha; } else { if ( face->palette_data.palette_flags && ( face->palette_data.palette_flags[face->palette_index] & FT_PALETTE_FOR_DARK_BACKGROUND ) ) { /* white opaque */ b = 0xFF; g = 0xFF; r = 0xFF; alpha = 0xFF; } else { /* black opaque */ b = 0x00; g = 0x00; r = 0x00; alpha = 0xFF; } } } else { b = face->palette[color_index].blue; g = face->palette[color_index].green; r = face->palette[color_index].red; alpha = face->palette[color_index].alpha; } /* 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 */