ref: f145e312dffc41a190beed96d681661d9c9d2d2a
dir: /src/base/ftglyph.c/
/***************************************************************************/
/* */
/* ftglyph.c */
/* */
/* FreeType convenience functions to handle glyphs (body). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005 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 <ft2build.h>
#include FT_GLYPH_H
#include FT_OUTLINE_H
#include FT_BITMAP_H
#include FT_INTERNAL_OBJECTS_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 trace_glyph
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** Convenience functions ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( void )
FT_Matrix_Multiply( const FT_Matrix* a,
FT_Matrix *b )
{
FT_Fixed xx, xy, yx, yy;
if ( !a || !b )
return;
xx = FT_MulFix( a->xx, b->xx ) + FT_MulFix( a->xy, b->yx );
xy = FT_MulFix( a->xx, b->xy ) + FT_MulFix( a->xy, b->yy );
yx = FT_MulFix( a->yx, b->xx ) + FT_MulFix( a->yy, b->yx );
yy = FT_MulFix( a->yx, b->xy ) + FT_MulFix( a->yy, b->yy );
b->xx = xx; b->xy = xy;
b->yx = yx; b->yy = yy;
}
/* documentation is in ftglyph.h */
FT_EXPORT_DEF( FT_Error )
FT_Matrix_Invert( FT_Matrix* matrix )
{
FT_Pos delta, xx, yy;
if ( !matrix )
return FT_Err_Invalid_Argument;
/* compute discriminant */
delta = FT_MulFix( matrix->xx, matrix->yy ) -
FT_MulFix( matrix->xy, matrix->yx );
if ( !delta )
return FT_Err_Invalid_Argument; /* matrix can't be inverted */
matrix->xy = - FT_DivFix( matrix->xy, delta );
matrix->yx = - FT_DivFix( matrix->yx, delta );
xx = matrix->xx;
yy = matrix->yy;
matrix->xx = FT_DivFix( yy, delta );
matrix->yy = FT_DivFix( xx, delta );
return FT_Err_Ok;
}
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** 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_Err_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_New( &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 << 6;
cbox->xMax = cbox->xMin + ( glyph->bitmap.width << 6 );
cbox->yMax = glyph->top << 6;
cbox->yMin = cbox->yMax - ( glyph->bitmap.rows << 6 );
}
FT_CALLBACK_TABLE_DEF
const FT_Glyph_Class ft_bitmap_glyph_class =
{
sizeof ( FT_BitmapGlyphRec ),
FT_GLYPH_FORMAT_BITMAP,
ft_bitmap_glyph_init,
ft_bitmap_glyph_done,
ft_bitmap_glyph_copy,
0, /* FT_Glyph_TransformFunc */
ft_bitmap_glyph_bbox,
0 /* FT_Glyph_PrepareFunc */
};
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** 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_Err_Invalid_Glyph_Format;
goto Exit;
}
/* allocate new outline */
error = FT_Outline_New( library, 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, 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_CALLBACK_TABLE_DEF
const FT_Glyph_Class ft_outline_glyph_class =
{
sizeof ( FT_OutlineGlyphRec ),
FT_GLYPH_FORMAT_OUTLINE,
ft_outline_glyph_init,
ft_outline_glyph_done,
ft_outline_glyph_copy,
ft_outline_glyph_transform,
ft_outline_glyph_bbox,
ft_outline_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;
*aglyph = 0;
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_Err_Invalid_Argument;
goto Exit;
}
*target = 0;
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_DEF( FT_Error )
FT_Get_Glyph( FT_GlyphSlot slot,
FT_Glyph *aglyph )
{
FT_Library library;
FT_Error error;
FT_Glyph glyph;
const FT_Glyph_Class* clazz = 0;
if ( !slot )
return FT_Err_Invalid_Slot_Handle;
library = slot->library;
if ( !aglyph )
return FT_Err_Invalid_Argument;
/* if it is a bitmap, that's easy :-) */
if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
clazz = &ft_bitmap_glyph_class;
/* it it is an outline too */
else if ( slot->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, slot->format, 0 );
if ( render )
clazz = &render->glyph_class;
}
if ( !clazz )
{
error = FT_Err_Invalid_Glyph_Format;
goto Exit;
}
/* create FT_Glyph object */
error = ft_new_glyph( library, clazz, &glyph );
if ( error )
goto Exit;
/* copy advance while converting it to 16.16 format */
glyph->advance.x = slot->advance.x << 10;
glyph->advance.y = slot->advance.y << 10;
/* now import the image from the glyph slot */
error = clazz->glyph_init( glyph, slot );
/* 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 )
{
const FT_Glyph_Class* clazz;
FT_Error error = FT_Err_Ok;
if ( !glyph || !glyph->clazz )
error = FT_Err_Invalid_Argument;
else
{
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_Err_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;
else
{
clazz = glyph->clazz;
if ( !clazz->glyph_bbox )
return;
else
{
/* 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( acbox->xMax );
acbox->yMax = FT_PIX_CEIL( 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;
}
}
}
return;
}
/* 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 glyph;
FT_BitmapGlyph bitmap = NULL;
const FT_Glyph_Class* clazz;
/* check argument */
if ( !the_glyph )
goto Bad;
/* we render the glyph into a glyph bitmap using a `dummy' glyph slot */
/* then calling FT_Render_Glyph_Internal() */
glyph = *the_glyph;
if ( !glyph )
goto Bad;
clazz = glyph->clazz;
/* when called with a bitmap glyph, do nothing and return successfully */
if ( clazz == &ft_bitmap_glyph_class )
goto Exit;
if ( !clazz || !clazz->glyph_prepare )
goto Bad;
FT_MEM_ZERO( &dummy, sizeof ( dummy ) );
FT_MEM_ZERO( &dummy_internal, sizeof ( dummy_internal ) );
dummy.internal = &dummy_internal;
dummy.library = glyph->library;
dummy.format = clazz->glyph_format;
/* create result bitmap glyph */
error = ft_new_glyph( glyph->library, &ft_bitmap_glyph_class,
(FT_Glyph*)(void*)&bitmap );
if ( error )
goto Exit;
#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_Err_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 */