ref: d1540c7f666e3c5d636b48c956b444205b50502d
dir: /libfreetype/ftglyph.c/
/***************************************************************************/
/* */
/* ftglyph.c */
/* */
/* FreeType convenience functions to handle glyphs (body). */
/* */
/* Copyright 1996-2001, 2002 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_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( 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 ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
static FT_Error
ft_bitmap_copy( FT_Memory memory,
FT_Bitmap* source,
FT_Bitmap* target )
{
FT_Error error;
FT_Int pitch = source->pitch;
FT_ULong size;
*target = *source;
if ( pitch < 0 )
pitch = -pitch;
size = (FT_ULong)( pitch * source->rows );
if ( !FT_ALLOC( target->buffer, size ) )
FT_MEM_COPY( target->buffer, source->buffer, size );
return error;
}
static FT_Error
ft_bitmap_glyph_init( FT_BitmapGlyph glyph,
FT_GlyphSlot slot )
{
FT_Error error = FT_Err_Ok;
FT_Library library = FT_GLYPH(glyph)->library;
FT_Memory memory = library->memory;
if ( slot->format != FT_GLYPH_FORMAT_BITMAP )
{
error = FT_Err_Invalid_Glyph_Format;
goto Exit;
}
/* grab the bitmap in the slot - do lazy copying whenever possible */
glyph->bitmap = slot->bitmap;
glyph->left = slot->bitmap_left;
glyph->top = slot->bitmap_top;
if ( slot->flags & FT_GLYPH_OWN_BITMAP )
slot->flags &= ~FT_GLYPH_OWN_BITMAP;
else
{
/* copy the bitmap into a new buffer */
error = ft_bitmap_copy( memory, &slot->bitmap, &glyph->bitmap );
}
Exit:
return error;
}
static FT_Error
ft_bitmap_glyph_copy( FT_BitmapGlyph source,
FT_BitmapGlyph target )
{
FT_Memory memory = source->root.library->memory;
target->left = source->left;
target->top = source->top;
return ft_bitmap_copy( memory, &source->bitmap, &target->bitmap );
}
static void
ft_bitmap_glyph_done( FT_BitmapGlyph glyph )
{
FT_Memory memory = FT_GLYPH(glyph)->library->memory;
FT_FREE( glyph->bitmap.buffer );
}
static void
ft_bitmap_glyph_bbox( FT_BitmapGlyph glyph,
FT_BBox* cbox )
{
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 );
}
const FT_Glyph_Class ft_bitmap_glyph_class =
{
sizeof( FT_BitmapGlyphRec ),
FT_GLYPH_FORMAT_BITMAP,
(FT_Glyph_InitFunc) ft_bitmap_glyph_init,
(FT_Glyph_DoneFunc) ft_bitmap_glyph_done,
(FT_Glyph_CopyFunc) ft_bitmap_glyph_copy,
(FT_Glyph_TransformFunc)0,
(FT_Glyph_GetBBoxFunc) ft_bitmap_glyph_bbox,
(FT_Glyph_PrepareFunc) 0
};
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** FT_OutlineGlyph support ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
static FT_Error
ft_outline_glyph_init( FT_OutlineGlyph glyph,
FT_GlyphSlot slot )
{
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;
/* copy it */
FT_MEM_COPY( target->points, source->points,
source->n_points * sizeof ( FT_Vector ) );
FT_MEM_COPY( target->tags, source->tags,
source->n_points * sizeof ( FT_Byte ) );
FT_MEM_COPY( target->contours, source->contours,
source->n_contours * sizeof ( FT_Short ) );
/* copy all flags, except the `FT_OUTLINE_OWNER' one */
target->flags = source->flags | FT_OUTLINE_OWNER;
Exit:
return error;
}
static void
ft_outline_glyph_done( FT_OutlineGlyph glyph )
{
FT_Outline_Done( FT_GLYPH( glyph )->library, &glyph->outline );
}
static FT_Error
ft_outline_glyph_copy( FT_OutlineGlyph source,
FT_OutlineGlyph 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;
}
static void
ft_outline_glyph_transform( FT_OutlineGlyph glyph,
FT_Matrix* matrix,
FT_Vector* delta )
{
if ( matrix )
FT_Outline_Transform( &glyph->outline, matrix );
if ( delta )
FT_Outline_Translate( &glyph->outline, delta->x, delta->y );
}
static void
ft_outline_glyph_bbox( FT_OutlineGlyph glyph,
FT_BBox* bbox )
{
FT_Outline_Get_CBox( &glyph->outline, bbox );
}
static FT_Error
ft_outline_glyph_prepare( FT_OutlineGlyph glyph,
FT_GlyphSlot slot )
{
slot->format = FT_GLYPH_FORMAT_OUTLINE;
slot->outline = glyph->outline;
slot->outline.flags &= ~FT_OUTLINE_OWNER;
return FT_Err_Ok;
}
const FT_Glyph_Class ft_outline_glyph_class =
{
sizeof( FT_OutlineGlyphRec ),
FT_GLYPH_FORMAT_OUTLINE,
(FT_Glyph_InitFunc) ft_outline_glyph_init,
(FT_Glyph_DoneFunc) ft_outline_glyph_done,
(FT_Glyph_CopyFunc) ft_outline_glyph_copy,
(FT_Glyph_TransformFunc)ft_outline_glyph_transform,
(FT_Glyph_GetBBoxFunc) ft_outline_glyph_bbox,
(FT_Glyph_PrepareFunc) 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 = slot->library;
FT_Error error;
FT_Glyph glyph;
const FT_Glyph_Class* clazz = 0;
if ( !slot )
return FT_Err_Invalid_Slot_Handle;
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 )
{
acbox->xMin &= -64;
acbox->yMin &= -64;
acbox->xMax = ( acbox->xMax + 63 ) & -64;
acbox->yMax = ( acbox->yMax + 63 ) & -64;
}
/* convert to integer pixels if needed */
if ( bbox_mode & ft_glyph_bbox_truncate )
{
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_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 succesfully */
if ( clazz == &ft_bitmap_glyph_class )
goto Exit;
if ( !clazz || !clazz->glyph_prepare )
goto Bad;
FT_MEM_ZERO( &dummy, sizeof ( dummy ) );
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*)&bitmap );
if ( error )
goto Exit;
#if 0
/* 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 0
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( 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 */