ref: 2de1b5630d7717f5fc5401a7ca3aa756d3c204fd
dir: /src/base/ftgloadr.c/
/****************************************************************************
*
* ftgloadr.c
*
* The FreeType glyph loader (body).
*
* Copyright (C) 2002-2020 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.
*
*/
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftgloadr.h>
#include <freetype/internal/ftmemory.h>
#include <freetype/internal/ftobjs.h>
#undef FT_COMPONENT
#define FT_COMPONENT gloader
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** *****/
/***** G L Y P H L O A D E R *****/
/***** *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**************************************************************************
*
* The glyph loader is a simple object which is used to load a set of
* glyphs easily. It is critical for the correct loading of composites.
*
* Ideally, one can see it as a stack of abstract `glyph' objects.
*
* loader.base Is really the bottom of the stack. It describes a
* single glyph image made of the juxtaposition of
* several glyphs (those `in the stack').
*
* loader.current Describes the top of the stack, on which a new
* glyph can be loaded.
*
* Rewind Clears the stack.
* Prepare Set up `loader.current' for addition of a new glyph
* image.
* Add Add the `current' glyph image to the `base' one,
* and prepare for another one.
*
* The glyph loader is now a base object. Each driver used to
* re-implement it in one way or the other, which wasted code and
* energy.
*
*/
/* create a new glyph loader */
FT_BASE_DEF( FT_Error )
FT_GlyphLoader_New( FT_Memory memory,
FT_GlyphLoader *aloader )
{
FT_GlyphLoader loader = NULL;
FT_Error error;
if ( !FT_NEW( loader ) )
{
loader->memory = memory;
*aloader = loader;
}
return error;
}
/* rewind the glyph loader - reset counters to 0 */
FT_BASE_DEF( void )
FT_GlyphLoader_Rewind( FT_GlyphLoader loader )
{
FT_GlyphLoad base = &loader->base;
FT_GlyphLoad current = &loader->current;
base->outline.n_points = 0;
base->outline.n_contours = 0;
base->outline.flags = 0;
base->num_subglyphs = 0;
*current = *base;
}
/* reset glyph loader, free all allocated tables, */
/* and start from zero */
FT_BASE_DEF( void )
FT_GlyphLoader_Reset( FT_GlyphLoader loader )
{
FT_Memory memory = loader->memory;
FT_FREE( loader->base.outline.points );
FT_FREE( loader->base.outline.tags );
FT_FREE( loader->base.outline.contours );
FT_FREE( loader->base.extra_points );
FT_FREE( loader->base.subglyphs );
loader->base.extra_points2 = NULL;
loader->max_points = 0;
loader->max_contours = 0;
loader->max_subglyphs = 0;
FT_GlyphLoader_Rewind( loader );
}
/* delete a glyph loader */
FT_BASE_DEF( void )
FT_GlyphLoader_Done( FT_GlyphLoader loader )
{
if ( loader )
{
FT_Memory memory = loader->memory;
FT_GlyphLoader_Reset( loader );
FT_FREE( loader );
}
}
/* re-adjust the `current' outline fields */
static void
FT_GlyphLoader_Adjust_Points( FT_GlyphLoader loader )
{
FT_Outline* base = &loader->base.outline;
FT_Outline* current = &loader->current.outline;
current->points = FT_OFFSET( base->points, base->n_points );
current->tags = FT_OFFSET( base->tags, base->n_points );
current->contours = FT_OFFSET( base->contours, base->n_contours );
/* handle extra points table - if any */
if ( loader->use_extra )
{
loader->current.extra_points = loader->base.extra_points +
base->n_points;
loader->current.extra_points2 = loader->base.extra_points2 +
base->n_points;
}
}
FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CreateExtra( FT_GlyphLoader loader )
{
FT_Error error;
FT_Memory memory = loader->memory;
if ( loader->max_points == 0 ||
loader->base.extra_points != NULL )
return FT_Err_Ok;
if ( !FT_NEW_ARRAY( loader->base.extra_points, 2 * loader->max_points ) )
{
loader->use_extra = 1;
loader->base.extra_points2 = loader->base.extra_points +
loader->max_points;
FT_GlyphLoader_Adjust_Points( loader );
}
return error;
}
/* re-adjust the `current' subglyphs field */
static void
FT_GlyphLoader_Adjust_Subglyphs( FT_GlyphLoader loader )
{
FT_GlyphLoad base = &loader->base;
FT_GlyphLoad current = &loader->current;
current->subglyphs = FT_OFFSET( base->subglyphs, base->num_subglyphs );
}
/* Ensure that we can add `n_points' and `n_contours' to our glyph. */
/* This function reallocates its outline tables if necessary. Note that */
/* it DOESN'T change the number of points within the loader! */
/* */
FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CheckPoints( FT_GlyphLoader loader,
FT_UInt n_points,
FT_UInt n_contours )
{
FT_Memory memory = loader->memory;
FT_Error error = FT_Err_Ok;
FT_Outline* base = &loader->base.outline;
FT_Outline* current = &loader->current.outline;
FT_Bool adjust = 0;
FT_UInt new_max, old_max;
error = FT_GlyphLoader_CreateExtra( loader );
if ( error )
return error;
/* check points & tags */
new_max = (FT_UInt)base->n_points + (FT_UInt)current->n_points +
n_points;
old_max = loader->max_points;
if ( new_max > old_max )
{
new_max = FT_PAD_CEIL( new_max, 8 );
if ( new_max > FT_OUTLINE_POINTS_MAX )
return FT_THROW( Array_Too_Large );
if ( FT_RENEW_ARRAY( base->points, old_max, new_max ) ||
FT_RENEW_ARRAY( base->tags, old_max, new_max ) )
goto Exit;
if ( loader->use_extra )
{
if ( FT_RENEW_ARRAY( loader->base.extra_points,
old_max * 2, new_max * 2 ) )
goto Exit;
FT_ARRAY_MOVE( loader->base.extra_points + new_max,
loader->base.extra_points + old_max,
old_max );
loader->base.extra_points2 = loader->base.extra_points + new_max;
}
adjust = 1;
loader->max_points = new_max;
}
error = FT_GlyphLoader_CreateExtra( loader );
if ( error )
return error;
/* check contours */
old_max = loader->max_contours;
new_max = (FT_UInt)base->n_contours + (FT_UInt)current->n_contours +
n_contours;
if ( new_max > old_max )
{
new_max = FT_PAD_CEIL( new_max, 4 );
if ( new_max > FT_OUTLINE_CONTOURS_MAX )
return FT_THROW( Array_Too_Large );
if ( FT_RENEW_ARRAY( base->contours, old_max, new_max ) )
goto Exit;
adjust = 1;
loader->max_contours = new_max;
}
if ( adjust )
FT_GlyphLoader_Adjust_Points( loader );
Exit:
if ( error )
FT_GlyphLoader_Reset( loader );
return error;
}
/* Ensure that we can add `n_subglyphs' to our glyph. this function */
/* reallocates its subglyphs table if necessary. Note that it DOES */
/* NOT change the number of subglyphs within the loader! */
/* */
FT_BASE_DEF( FT_Error )
FT_GlyphLoader_CheckSubGlyphs( FT_GlyphLoader loader,
FT_UInt n_subs )
{
FT_Memory memory = loader->memory;
FT_Error error = FT_Err_Ok;
FT_UInt new_max, old_max;
FT_GlyphLoad base = &loader->base;
FT_GlyphLoad current = &loader->current;
new_max = base->num_subglyphs + current->num_subglyphs + n_subs;
old_max = loader->max_subglyphs;
if ( new_max > old_max )
{
new_max = FT_PAD_CEIL( new_max, 2 );
if ( FT_RENEW_ARRAY( base->subglyphs, old_max, new_max ) )
goto Exit;
loader->max_subglyphs = new_max;
FT_GlyphLoader_Adjust_Subglyphs( loader );
}
Exit:
return error;
}
/* prepare loader for the addition of a new glyph on top of the base one */
FT_BASE_DEF( void )
FT_GlyphLoader_Prepare( FT_GlyphLoader loader )
{
FT_GlyphLoad current = &loader->current;
current->outline.n_points = 0;
current->outline.n_contours = 0;
current->num_subglyphs = 0;
FT_GlyphLoader_Adjust_Points ( loader );
FT_GlyphLoader_Adjust_Subglyphs( loader );
}
/* add current glyph to the base image -- and prepare for another */
FT_BASE_DEF( void )
FT_GlyphLoader_Add( FT_GlyphLoader loader )
{
FT_GlyphLoad base;
FT_GlyphLoad current;
FT_Int n_curr_contours;
FT_Int n_base_points;
FT_Int n;
if ( !loader )
return;
base = &loader->base;
current = &loader->current;
n_curr_contours = current->outline.n_contours;
n_base_points = base->outline.n_points;
base->outline.n_points =
(short)( base->outline.n_points + current->outline.n_points );
base->outline.n_contours =
(short)( base->outline.n_contours + current->outline.n_contours );
base->num_subglyphs += current->num_subglyphs;
/* adjust contours count in newest outline */
for ( n = 0; n < n_curr_contours; n++ )
current->outline.contours[n] =
(short)( current->outline.contours[n] + n_base_points );
/* prepare for another new glyph image */
FT_GlyphLoader_Prepare( loader );
}
/* END */