ref: eb2b5bb10754da426b4ea9da78fbb017f0bcb9ec
dir: /src/base/ftglyph.c/
/****************************************************************************
*
* ftglyph.c
*
* FreeType convenience functions to handle glyphs (body).
*
* Copyright (C) 1996-2020 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* 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.
*
*/
/**************************************************************************
*
* This file contains the definition of several convenience functions
* that can be used by client applications to easily retrieve glyph
* bitmaps and outlines from a given face.
*
* These functions should be optional if you are writing a font server
* or text layout engine on top of FreeType. However, they are pretty
* handy for many other simple uses of the library.
*
*/
#include <freetype/internal/ftdebug.h>
#include <freetype/ftglyph.h>
#include <freetype/ftoutln.h>
#include <freetype/ftbitmap.h>
#include <freetype/internal/ftobjs.h>
#include "ftbase.h"
/**************************************************************************
*
* 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 glyph
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** FT_BitmapGlyph support ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
FT_CALLBACK_DEF( FT_Error )
ft_bitmap_glyph_init( FT_Glyph bitmap_glyph,
FT_GlyphSlot slot )
{
FT_BitmapGlyph glyph = (FT_BitmapGlyph)bitmap_glyph;
FT_Error error = FT_Err_Ok;
FT_Library library = FT_GLYPH( glyph )->library;
if ( slot->format != FT_GLYPH_FORMAT_BITMAP )
{
error = FT_THROW( Invalid_Glyph_Format );
goto Exit;
}
glyph->left = slot->bitmap_left;
glyph->top = slot->bitmap_top;
/* do lazy copying whenever possible */
if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
{
glyph->bitmap = slot->bitmap;
slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
}
else
{
FT_Bitmap_Init( &glyph->bitmap );
error = FT_Bitmap_Copy( library, &slot->bitmap, &glyph->bitmap );
}
Exit:
return error;
}
FT_CALLBACK_DEF( FT_Error )
ft_bitmap_glyph_copy( FT_Glyph bitmap_source,
FT_Glyph bitmap_target )
{
FT_Library library = bitmap_source->library;
FT_BitmapGlyph source = (FT_BitmapGlyph)bitmap_source;
FT_BitmapGlyph target = (FT_BitmapGlyph)bitmap_target;
target->left = source->left;
target->top = source->top;
return FT_Bitmap_Copy( library, &source->bitmap, &target->bitmap );
}
FT_CALLBACK_DEF( void )
ft_bitmap_glyph_done( FT_Glyph bitmap_glyph )
{
FT_BitmapGlyph glyph = (FT_BitmapGlyph)bitmap_glyph;
FT_Library library = FT_GLYPH( glyph )->library;
FT_Bitmap_Done( library, &glyph->bitmap );
}
FT_CALLBACK_DEF( void )
ft_bitmap_glyph_bbox( FT_Glyph bitmap_glyph,
FT_BBox* cbox )
{
FT_BitmapGlyph glyph = (FT_BitmapGlyph)bitmap_glyph;
cbox->xMin = glyph->left * 64;
cbox->xMax = cbox->xMin + (FT_Pos)( glyph->bitmap.width * 64 );
cbox->yMax = glyph->top * 64;
cbox->yMin = cbox->yMax - (FT_Pos)( glyph->bitmap.rows * 64 );
}
FT_DEFINE_GLYPH(
ft_bitmap_glyph_class,
sizeof ( FT_BitmapGlyphRec ),
FT_GLYPH_FORMAT_BITMAP,
ft_bitmap_glyph_init, /* FT_Glyph_InitFunc glyph_init */
ft_bitmap_glyph_done, /* FT_Glyph_DoneFunc glyph_done */
ft_bitmap_glyph_copy, /* FT_Glyph_CopyFunc glyph_copy */
NULL, /* FT_Glyph_TransformFunc glyph_transform */
ft_bitmap_glyph_bbox, /* FT_Glyph_GetBBoxFunc glyph_bbox */
NULL /* FT_Glyph_PrepareFunc glyph_prepare */
)
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** FT_OutlineGlyph support ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
FT_CALLBACK_DEF( FT_Error )
ft_outline_glyph_init( FT_Glyph outline_glyph,
FT_GlyphSlot slot )
{
FT_OutlineGlyph glyph = (FT_OutlineGlyph)outline_glyph;
FT_Error error = FT_Err_Ok;
FT_Library library = FT_GLYPH( glyph )->library;
FT_Outline* source = &slot->outline;
FT_Outline* target = &glyph->outline;
/* check format in glyph slot */
if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
{
error = FT_THROW( Invalid_Glyph_Format );
goto Exit;
}
/* allocate new outline */
error = FT_Outline_New( library,
(FT_UInt)source->n_points,
source->n_contours,
&glyph->outline );
if ( error )
goto Exit;
FT_Outline_Copy( source, target );
Exit:
return error;
}
FT_CALLBACK_DEF( void )
ft_outline_glyph_done( FT_Glyph outline_glyph )
{
FT_OutlineGlyph glyph = (FT_OutlineGlyph)outline_glyph;
FT_Outline_Done( FT_GLYPH( glyph )->library, &glyph->outline );
}
FT_CALLBACK_DEF( FT_Error )
ft_outline_glyph_copy( FT_Glyph outline_source,
FT_Glyph outline_target )
{
FT_OutlineGlyph source = (FT_OutlineGlyph)outline_source;
FT_OutlineGlyph target = (FT_OutlineGlyph)outline_target;
FT_Error error;
FT_Library library = FT_GLYPH( source )->library;
error = FT_Outline_New( library,
(FT_UInt)source->outline.n_points,
source->outline.n_contours,
&target->outline );
if ( !error )
FT_Outline_Copy( &source->outline, &target->outline );
return error;
}
FT_CALLBACK_DEF( void )
ft_outline_glyph_transform( FT_Glyph outline_glyph,
const FT_Matrix* matrix,
const FT_Vector* delta )
{
FT_OutlineGlyph glyph = (FT_OutlineGlyph)outline_glyph;
if ( matrix )
FT_Outline_Transform( &glyph->outline, matrix );
if ( delta )
FT_Outline_Translate( &glyph->outline, delta->x, delta->y );
}
FT_CALLBACK_DEF( void )
ft_outline_glyph_bbox( FT_Glyph outline_glyph,
FT_BBox* bbox )
{
FT_OutlineGlyph glyph = (FT_OutlineGlyph)outline_glyph;
FT_Outline_Get_CBox( &glyph->outline, bbox );
}
FT_CALLBACK_DEF( FT_Error )
ft_outline_glyph_prepare( FT_Glyph outline_glyph,
FT_GlyphSlot slot )
{
FT_OutlineGlyph glyph = (FT_OutlineGlyph)outline_glyph;
slot->format = FT_GLYPH_FORMAT_OUTLINE;
slot->outline = glyph->outline;
slot->outline.flags &= ~FT_OUTLINE_OWNER;
return FT_Err_Ok;
}
FT_DEFINE_GLYPH(
ft_outline_glyph_class,
sizeof ( FT_OutlineGlyphRec ),
FT_GLYPH_FORMAT_OUTLINE,
ft_outline_glyph_init, /* FT_Glyph_InitFunc glyph_init */
ft_outline_glyph_done, /* FT_Glyph_DoneFunc glyph_done */
ft_outline_glyph_copy, /* FT_Glyph_CopyFunc glyph_copy */
ft_outline_glyph_transform, /* FT_Glyph_TransformFunc glyph_transform */
ft_outline_glyph_bbox, /* FT_Glyph_GetBBoxFunc glyph_bbox */
ft_outline_glyph_prepare /* FT_Glyph_PrepareFunc glyph_prepare */
)
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** FT_Glyph class and API ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
static FT_Error
ft_new_glyph( FT_Library library,
const FT_Glyph_Class* clazz,
FT_Glyph* aglyph )
{
FT_Memory memory = library->memory;
FT_Error error;
FT_Glyph glyph = NULL;
*aglyph = NULL;
if ( !FT_ALLOC( glyph, clazz->glyph_size ) )
{
glyph->library = library;
glyph->clazz = clazz;
glyph->format = clazz->glyph_format;
*aglyph = glyph;
}
return error;
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( FT_Error )
FT_Glyph_Copy( FT_Glyph source,
FT_Glyph *target )
{
FT_Glyph copy;
FT_Error error;
const FT_Glyph_Class* clazz;
/* check arguments */
if ( !target || !source || !source->clazz )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
*target = NULL;
if ( !source || !source->clazz )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
clazz = source->clazz;
error = ft_new_glyph( source->library, clazz, © );
if ( error )
goto Exit;
copy->advance = source->advance;
copy->format = source->format;
if ( clazz->glyph_copy )
error = clazz->glyph_copy( source, copy );
if ( error )
FT_Done_Glyph( copy );
else
*target = copy;
Exit:
return error;
}
/* documentation is in ftglyph.h */
FT_EXPORT( FT_Error )
FT_New_Glyph( FT_Library library,
FT_Glyph_Format format,
FT_Glyph *aglyph )
{
const FT_Glyph_Class* clazz = NULL;
if ( !library || !aglyph )
return FT_THROW( Invalid_Argument );
/* if it is a bitmap, that's easy :-) */
if ( format == FT_GLYPH_FORMAT_BITMAP )
clazz = &ft_bitmap_glyph_class;
/* if it is an outline */
else if ( format == FT_GLYPH_FORMAT_OUTLINE )
clazz = &ft_outline_glyph_class;
else
{
/* try to find a renderer that supports the glyph image format */
FT_Renderer render = FT_Lookup_Renderer( library, format, 0 );
if ( render )
clazz = &render->glyph_class;
}
if ( !clazz )
return FT_THROW( Invalid_Glyph_Format );
/* create FT_Glyph object */
return ft_new_glyph( library, clazz, aglyph );
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( FT_Error )
FT_Get_Glyph( FT_GlyphSlot slot,
FT_Glyph *aglyph )
{
FT_Error error;
FT_Glyph glyph;
if ( !slot )
return FT_THROW( Invalid_Slot_Handle );
if ( !aglyph )
return FT_THROW( Invalid_Argument );
/* create FT_Glyph object */
error = FT_New_Glyph( slot->library, slot->format, &glyph );
if ( error )
goto Exit;
/* copy advance while converting 26.6 to 16.16 format */
if ( slot->advance.x >= 0x8000L * 64 ||
slot->advance.x <= -0x8000L * 64 )
{
FT_ERROR(( "FT_Get_Glyph: advance width too large\n" ));
error = FT_THROW( Invalid_Argument );
goto Exit2;
}
if ( slot->advance.y >= 0x8000L * 64 ||
slot->advance.y <= -0x8000L * 64 )
{
FT_ERROR(( "FT_Get_Glyph: advance height too large\n" ));
error = FT_THROW( Invalid_Argument );
goto Exit2;
}
glyph->advance.x = slot->advance.x * 1024;
glyph->advance.y = slot->advance.y * 1024;
/* now import the image from the glyph slot */
error = glyph->clazz->glyph_init( glyph, slot );
Exit2:
/* if an error occurred, destroy the glyph */
if ( error )
FT_Done_Glyph( glyph );
else
*aglyph = glyph;
Exit:
return error;
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( FT_Error )
FT_Glyph_Transform( FT_Glyph glyph,
FT_Matrix* matrix,
FT_Vector* delta )
{
FT_Error error = FT_Err_Ok;
if ( !glyph || !glyph->clazz )
error = FT_THROW( Invalid_Argument );
else
{
const FT_Glyph_Class* clazz = glyph->clazz;
if ( clazz->glyph_transform )
{
/* transform glyph image */
clazz->glyph_transform( glyph, matrix, delta );
/* transform advance vector */
if ( matrix )
FT_Vector_Transform( &glyph->advance, matrix );
}
else
error = FT_THROW( Invalid_Glyph_Format );
}
return error;
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( void )
FT_Glyph_Get_CBox( FT_Glyph glyph,
FT_UInt bbox_mode,
FT_BBox *acbox )
{
const FT_Glyph_Class* clazz;
if ( !acbox )
return;
acbox->xMin = acbox->yMin = acbox->xMax = acbox->yMax = 0;
if ( !glyph || !glyph->clazz )
return;
clazz = glyph->clazz;
if ( !clazz->glyph_bbox )
return;
/* retrieve bbox in 26.6 coordinates */
clazz->glyph_bbox( glyph, acbox );
/* perform grid fitting if needed */
if ( bbox_mode == FT_GLYPH_BBOX_GRIDFIT ||
bbox_mode == FT_GLYPH_BBOX_PIXELS )
{
acbox->xMin = FT_PIX_FLOOR( acbox->xMin );
acbox->yMin = FT_PIX_FLOOR( acbox->yMin );
acbox->xMax = FT_PIX_CEIL_LONG( acbox->xMax );
acbox->yMax = FT_PIX_CEIL_LONG( acbox->yMax );
}
/* convert to integer pixels if needed */
if ( bbox_mode == FT_GLYPH_BBOX_TRUNCATE ||
bbox_mode == FT_GLYPH_BBOX_PIXELS )
{
acbox->xMin >>= 6;
acbox->yMin >>= 6;
acbox->xMax >>= 6;
acbox->yMax >>= 6;
}
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( FT_Error )
FT_Glyph_To_Bitmap( FT_Glyph* the_glyph,
FT_Render_Mode render_mode,
FT_Vector* origin,
FT_Bool destroy )
{
FT_GlyphSlotRec dummy;
FT_GlyphSlot_InternalRec dummy_internal;
FT_Error error = FT_Err_Ok;
FT_Glyph b, glyph;
FT_BitmapGlyph bitmap = NULL;
const FT_Glyph_Class* clazz;
FT_Library library;
/* check argument */
if ( !the_glyph )
goto Bad;
glyph = *the_glyph;
if ( !glyph )
goto Bad;
clazz = glyph->clazz;
library = glyph->library;
if ( !library || !clazz )
goto Bad;
/* when called with a bitmap glyph, do nothing and return successfully */
if ( clazz == &ft_bitmap_glyph_class )
goto Exit;
if ( !clazz->glyph_prepare )
goto Bad;
/* we render the glyph into a glyph bitmap using a `dummy' glyph slot */
/* then calling FT_Render_Glyph_Internal() */
FT_ZERO( &dummy );
FT_ZERO( &dummy_internal );
dummy.internal = &dummy_internal;
dummy.library = library;
dummy.format = clazz->glyph_format;
/* create result bitmap glyph */
error = ft_new_glyph( library, &ft_bitmap_glyph_class, &b );
if ( error )
goto Exit;
bitmap = (FT_BitmapGlyph)b;
#if 1
/* if `origin' is set, translate the glyph image */
if ( origin )
FT_Glyph_Transform( glyph, 0, origin );
#else
FT_UNUSED( origin );
#endif
/* prepare dummy slot for rendering */
error = clazz->glyph_prepare( glyph, &dummy );
if ( !error )
error = FT_Render_Glyph_Internal( glyph->library, &dummy, render_mode );
#if 1
if ( !destroy && origin )
{
FT_Vector v;
v.x = -origin->x;
v.y = -origin->y;
FT_Glyph_Transform( glyph, 0, &v );
}
#endif
if ( error )
goto Exit;
/* in case of success, copy the bitmap to the glyph bitmap */
error = ft_bitmap_glyph_init( (FT_Glyph)bitmap, &dummy );
if ( error )
goto Exit;
/* copy advance */
bitmap->root.advance = glyph->advance;
if ( destroy )
FT_Done_Glyph( glyph );
*the_glyph = FT_GLYPH( bitmap );
Exit:
if ( error && bitmap )
FT_Done_Glyph( FT_GLYPH( bitmap ) );
return error;
Bad:
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( void )
FT_Done_Glyph( FT_Glyph glyph )
{
if ( glyph )
{
FT_Memory memory = glyph->library->memory;
const FT_Glyph_Class* clazz = glyph->clazz;
if ( clazz->glyph_done )
clazz->glyph_done( glyph );
FT_FREE( glyph );
}
}
/* END */