/***************************************************************************/
/* */
/* ftglyph.c */
/* */
/* FreeType convenience functions to handle glyphs (body). */
/* */
/* Copyright 1996-2000 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/ftglyph.h>
#include <freetype/ftoutln.h>
#include <freetype/internal/ftobjs.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 ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Multiply */
/* */
/* <Description> */
/* Performs the matrix operation `b = a*b'. */
/* */
/* <Input> */
/* a :: A pointer to matrix `a'. */
/* */
/* <InOut> */
/* b :: A pointer to matrix `b'. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
/* <Note> */
/* The result is undefined if either `a' or `b' is zero. */
/* */
FT_EXPORT_FUNC( 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;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Invert */
/* */
/* <Description> */
/* Inverts a 2x2 matrix. Returns an error if it can't be inverted. */
/* */
/* <InOut> */
/* matrix :: A pointer to the target matrix. Remains untouched in */
/* case of error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
FT_EXPORT_FUNC( 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 ( !ALLOC( target->buffer, size ) )
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;
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_Init_Func) ft_bitmap_glyph_init,
(FT_Glyph_Done_Func) ft_bitmap_glyph_done,
(FT_Glyph_Copy_Func) ft_bitmap_glyph_copy,
(FT_Glyph_Transform_Func)0,
(FT_Glyph_BBox_Func) ft_bitmap_glyph_bbox,
(FT_Glyph_Prepare_Func) 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 */
MEM_Copy( target->points, source->points,
source->n_points * sizeof ( FT_Vector ) );
MEM_Copy( target->tags, source->tags,
source->n_points * sizeof ( FT_Byte ) );
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_Init_Func) ft_outline_glyph_init,
(FT_Glyph_Done_Func) ft_outline_glyph_done,
(FT_Glyph_Copy_Func) ft_outline_glyph_copy,
(FT_Glyph_Transform_Func)ft_outline_glyph_transform,
(FT_Glyph_BBox_Func) ft_outline_glyph_bbox,
(FT_Glyph_Prepare_Func) 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 ( !ALLOC( glyph, clazz->glyph_size ) )
{
glyph->library = library;
glyph->clazz = clazz;
glyph->format = clazz->glyph_format;
*aglyph = glyph;
}
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Glyph_Copy */
/* */
/* <Description> */
/* A function used to copy a glyph image. */
/* */
/* <Input> */
/* source :: A handle to the source glyph object. */
/* */
/* <Output> */
/* target :: A handle to the target glyph object. 0 in case of */
/* error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_EXPORT_FUNC( 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;
if ( clazz->glyph_copy )
error = clazz->glyph_copy( source, copy );
if ( error )
FT_Done_Glyph( copy );
else
*target = copy;
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Get_Glyph */
/* */
/* <Description> */
/* A function used to extract a glyph image from a slot. */
/* */
/* <Input> */
/* slot :: A handle to the source glyph slot. */
/* */
/* <Output> */
/* aglyph :: A handle to the glyph object. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
FT_EXPORT_FUNC( 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;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Glyph_Transform */
/* */
/* <Description> */
/* Transforms a glyph image if its format is scalable. */
/* */
/* <Input> */
/* glyph :: A handle to the target glyph object. */
/* */
/* matrix :: A pointer to a 2x2 matrix to apply. */
/* */
/* delta :: A pointer to a 2d vector to apply. Coordinates are */
/* expressed in 1/64th of a pixel. */
/* */
/* <Return> */
/* FreeType error code (the glyph format is not scalable if it is */
/* not zero). */
/* */
/* <Note> */
/* The 2x2 transformation matrix is also applied to the glyph's */
/* advance vector. */
/* */
FT_EXPORT_FUNC( 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;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Glyph_Get_CBox */
/* */
/* <Description> */
/* Returns the glyph image's bounding box. */
/* */
/* <Input> */
/* glyph :: A handle to the source glyph object. */
/* */
/* mode :: The mode which indicates how to interpret the returned */
/* bounding box values. */
/* */
/* <Output> */
/* box :: The glyph bounding box. Coordinates are expressed in */
/* 1/64th of pixels if it is grid-fitted. */
/* */
/* <Note> */
/* Coordinates are relative to the glyph origin, using the Y-upwards */
/* convention. */
/* */
/* If the glyph has been loaded with FT_LOAD_NO_SCALE, `bbox_mode' */
/* must be set to `ft_glyph_bbox_unscaled' to get unscaled font */
/* units. */
/* */
/* If `bbox_mode' is set to `ft_glyph_bbox_subpixels' the bbox */
/* coordinates are returned in 26.6 pixels (i.e. 1/64th of pixels). */
/* */
/* Note that the maximum coordinates are exclusive, which means that */
/* one can compute the width and height of the glyph image (be it in */
/* integer or 26.6 pixels) as: */
/* */
/* width = bbox.xMax - bbox.xMin; */
/* height = bbox.yMax - bbox.yMin; */
/* */
/* Note also that for 26.6 coordinates, if `bbox_mode' is set to */
/* `ft_glyph_bbox_gridfit', the coordinates will also be grid-fitted, */
/* which corresponds to: */
/* */
/* bbox.xMin = FLOOR(bbox.xMin); */
/* bbox.yMin = FLOOR(bbox.yMin); */
/* bbox.xMax = CEILING(bbox.xMax); */
/* bbox.yMax = CEILING(bbox.yMax); */
/* */
/* To get the bbox in pixel coordinates, set `bbox_mode' to */
/* `ft_glyph_bbox_truncate'. */
/* */
/* To get the bbox in grid-fitted pixel coordinates, set `bbox_mode' */
/* to `ft_glyph_bbox_pixels'. */
/* */
/* The default value for `bbox_mode' is `ft_glyph_bbox_pixels'. */
/* */
FT_EXPORT_FUNC( void ) FT_Glyph_Get_CBox( FT_Glyph glyph,
FT_UInt bbox_mode,
FT_BBox* cbox )
{
const FT_Glyph_Class* clazz;
FT_Error error = FT_Err_Ok;
if ( !cbox || !glyph || !glyph->clazz )
error = FT_Err_Invalid_Argument;
else
{
clazz = glyph->clazz;
if ( !clazz->glyph_bbox )
error = FT_Err_Invalid_Glyph_Format;
else
{
/* retrieve bbox in 26.6 coordinates */
clazz->glyph_bbox( glyph, cbox );
/* perform grid fitting if needed */
if ( bbox_mode & ft_glyph_bbox_gridfit )
{
cbox->xMin &= -64;
cbox->yMin &= -64;
cbox->xMax = ( cbox->xMax + 63 ) & -64;
cbox->yMax = ( cbox->yMax + 63 ) & -64;
}
/* convert to integer pixels if needed */
if ( bbox_mode & ft_glyph_bbox_truncate )
{
cbox->xMin >>= 6;
cbox->yMin >>= 6;
cbox->xMax >>= 6;
cbox->yMax >>= 6;
}
}
}
return;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Glyph_To_Bitmap */
/* */
/* <Description> */
/* Converts a given glyph object to a bitmap glyph object. */
/* */
/* <InOut> */
/* glyph :: A pointer to a handle to the target glyph. */
/* */
/* <Input> */
/* render_mode :: A set of bit flags that describe how the data is */
/* */
/* */
/* origin :: A pointer to a vector used to translate the glyph */
/* image before rendering. Can be 0 (if no */
/* translation). The origin is expressed in */
/* 26.6 pixels. */
/* */
/* destroy :: A boolean that indicates that the original glyph */
/* image should be destroyed by this function. It is */
/* never destroyed in case of error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* The glyph image is translated with the `origin' vector before */
/* rendering. In case of error, it it translated back to its */
/* original position and the glyph is left untouched. */
/* */
/* The first parameter is a pointer to a FT_Glyph handle, that will */
/* be replaced by this function. Typically, you would use (omitting */
/* error handling): */
/* */
/* */
/* { */
/* FT_Glyph glyph; */
/* FT_BitmapGlyph glyph_bitmap; */
/* */
/* */
/* // load glyph */
/* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAUT ); */
/* */
/* // extract glyph image */
/* error = FT_Get_Glyph( face->glyph, &glyph ); */
/* */
/* // convert to a bitmap (default render mode + destroy old) */
/* if ( glyph->format != ft_glyph_format_bitmap ) */
/* { */
/* error = FT_Glyph_To_Bitmap( &glyph, ft_render_mode_default, */
/* 0, 1 ); */
/* if ( error ) // glyph unchanged */
/* ... */
/* } */
/* */
/* // access bitmap content by typecasting */
/* glyph_bitmap = (FT_BitmapGlyph)glyph; */
/* */
/* // do funny stuff with it, like blitting/drawing */
/* ... */
/* */
/* // discard glyph image (bitmap or not) */
/* FT_Done_Glyph( glyph ); */
/* } */
/* */
/* */
/* This function will always fail if the glyph's format isn't */
/* scalable. */
/* */
FT_EXPORT_FUNC( FT_Error ) FT_Glyph_To_Bitmap( FT_Glyph* the_glyph,
FT_ULong render_mode,
FT_Vector* origin,
FT_Bool destroy )
{
FT_GlyphSlotRec dummy;
FT_Error error;
FT_Glyph glyph;
FT_BitmapGlyph bitmap;
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;
if ( !clazz || !clazz->glyph_prepare )
goto Bad;
MEM_Set( &dummy, 0, sizeof ( dummy ) );
dummy.library = glyph->library;
dummy.format = clazz->glyph_format;
/* if `origin' is set, translate the glyph image */
if ( origin )
FT_Glyph_Transform( glyph, 0, origin );
/* create result bitmap glyph */
error = ft_new_glyph( glyph->library, &ft_bitmap_glyph_class,
(FT_Glyph*)&bitmap );
if ( error )
goto Exit;
/* prepare dummy slot for rendering */
error = clazz->glyph_prepare( glyph, &dummy );
if ( !error )
error = FT_Render_Glyph_Internal( glyph->library, &dummy, render_mode );
if ( !destroy && origin )
{
FT_Vector v;
v.x = -origin->x;
v.y = -origin->y;
FT_Glyph_Transform( glyph, 0, &v );
}
/* in case of success, copy the bitmap to the glyph bitmap */
if ( !error )
{
error = ft_bitmap_glyph_init( bitmap, &dummy );
if ( error )
{
/* this should never happen, but let's be safe */
FT_Done_Glyph( FT_GLYPH( bitmap ) );
goto Exit;
}
/* copy advance */
bitmap->root.advance = glyph->advance;
if ( destroy )
FT_Done_Glyph( glyph );
*the_glyph = FT_GLYPH( bitmap );
}
Exit:
return error;
Bad:
error = FT_Err_Invalid_Argument;
goto Exit;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Done_Glyph */
/* */
/* <Description> */
/* Destroys a given glyph. */
/* */
/* <Input> */
/* glyph :: A handle to the target glyph object. */
/* */
FT_EXPORT_FUNC( 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 );
FREE( glyph );
}
}
/* END */
