forked from minhngoc25a/freetype2
593 lines
16 KiB
C
593 lines
16 KiB
C
/****************************************************************************
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*
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* ftsdfrend.c
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*
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* Signed Distance Field renderer interface (body).
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*
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* Copyright (C) 2020-2021 by
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* David Turner, Robert Wilhelm, and Werner Lemberg.
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*
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* Written by Anuj Verma.
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*
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* This file is part of the FreeType project, and may only be used,
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* modified, and distributed under the terms of the FreeType project
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* license, LICENSE.TXT. By continuing to use, modify, or distribute
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* this file you indicate that you have read the license and
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* understand and accept it fully.
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*
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*/
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#include <freetype/internal/ftdebug.h>
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#include <freetype/internal/ftobjs.h>
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#include <freetype/internal/services/svprop.h>
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#include <freetype/ftoutln.h>
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#include <freetype/ftbitmap.h>
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#include "ftsdfrend.h"
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#include "ftsdf.h"
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#include "ftsdferrs.h"
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/**************************************************************************
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*
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* The macro FT_COMPONENT is used in trace mode. It is an implicit
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* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
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* messages during execution.
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*/
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#undef FT_COMPONENT
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#define FT_COMPONENT sdf
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/**************************************************************************
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*
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* macros and default property values
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*
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*/
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#define SDF_RENDERER( rend ) ( (SDF_Renderer)rend )
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/**************************************************************************
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*
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* for setting properties
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*
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*/
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/* property setter function */
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static FT_Error
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sdf_property_set( FT_Module module,
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const char* property_name,
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const void* value,
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FT_Bool value_is_string )
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{
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FT_Error error = FT_Err_Ok;
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SDF_Renderer render = SDF_RENDERER( FT_RENDERER( module ) );
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FT_UNUSED( value_is_string );
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if ( ft_strcmp( property_name, "spread" ) == 0 )
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{
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FT_Int val = *(const FT_Int*)value;
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if ( val > MAX_SPREAD || val < MIN_SPREAD )
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{
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FT_TRACE0(( "[sdf] sdf_property_set:"
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" the `spread' property can have a value\n" ));
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FT_TRACE0(( " "
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" within range [%d, %d] (value provided: %d)\n",
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MIN_SPREAD, MAX_SPREAD, val ));
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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render->spread = (FT_UInt)val;
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FT_TRACE7(( "[sdf] sdf_property_set:"
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" updated property `spread' to %d\n", val ));
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}
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else if ( ft_strcmp( property_name, "flip_sign" ) == 0 )
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{
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FT_Int val = *(const FT_Int*)value;
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render->flip_sign = val ? 1 : 0;
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FT_TRACE7(( "[sdf] sdf_property_set:"
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" updated property `flip_sign' to %d\n", val ));
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}
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else if ( ft_strcmp( property_name, "flip_y" ) == 0 )
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{
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FT_Int val = *(const FT_Int*)value;
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render->flip_y = val ? 1 : 0;
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FT_TRACE7(( "[sdf] sdf_property_set:"
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" updated property `flip_y' to %d\n", val ));
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}
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else if ( ft_strcmp( property_name, "overlaps" ) == 0 )
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{
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FT_Bool val = *(const FT_Bool*)value;
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render->overlaps = val;
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FT_TRACE7(( "[sdf] sdf_property_set:"
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" updated property `overlaps' to %d\n", val ));
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}
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else
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{
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FT_TRACE0(( "[sdf] sdf_property_set:"
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" missing property `%s'\n", property_name ));
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error = FT_THROW( Missing_Property );
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}
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Exit:
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return error;
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}
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/* property getter function */
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static FT_Error
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sdf_property_get( FT_Module module,
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const char* property_name,
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void* value )
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{
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FT_Error error = FT_Err_Ok;
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SDF_Renderer render = SDF_RENDERER( FT_RENDERER( module ) );
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if ( ft_strcmp( property_name, "spread" ) == 0 )
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{
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FT_UInt* val = (FT_UInt*)value;
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*val = render->spread;
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}
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else if ( ft_strcmp( property_name, "flip_sign" ) == 0 )
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{
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FT_Int* val = (FT_Int*)value;
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*val = render->flip_sign;
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}
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else if ( ft_strcmp( property_name, "flip_y" ) == 0 )
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{
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FT_Int* val = (FT_Int*)value;
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*val = render->flip_y;
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}
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else if ( ft_strcmp( property_name, "overlaps" ) == 0 )
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{
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FT_Int* val = (FT_Int*)value;
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*val = render->overlaps;
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}
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else
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{
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FT_TRACE0(( "[sdf] sdf_property_get:"
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" missing property `%s'\n", property_name ));
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error = FT_THROW( Missing_Property );
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}
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return error;
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}
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FT_DEFINE_SERVICE_PROPERTIESREC(
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sdf_service_properties,
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(FT_Properties_SetFunc)sdf_property_set, /* set_property */
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(FT_Properties_GetFunc)sdf_property_get ) /* get_property */
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FT_DEFINE_SERVICEDESCREC1(
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sdf_services,
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FT_SERVICE_ID_PROPERTIES, &sdf_service_properties )
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static FT_Module_Interface
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ft_sdf_requester( FT_Renderer render,
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const char* module_interface )
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{
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FT_UNUSED( render );
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return ft_service_list_lookup( sdf_services, module_interface );
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}
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/*************************************************************************/
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/*************************************************************************/
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/** **/
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/** OUTLINE TO SDF CONVERTER **/
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/** **/
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/*************************************************************************/
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/*************************************************************************/
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/**************************************************************************
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*
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* interface functions
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*
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*/
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static FT_Error
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ft_sdf_init( FT_Renderer render )
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{
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SDF_Renderer sdf_render = SDF_RENDERER( render );
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sdf_render->spread = DEFAULT_SPREAD;
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sdf_render->flip_sign = 0;
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sdf_render->flip_y = 0;
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sdf_render->overlaps = 0;
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return FT_Err_Ok;
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}
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static void
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ft_sdf_done( FT_Renderer render )
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{
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FT_UNUSED( render );
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}
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/* generate signed distance field from a glyph's slot image */
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static FT_Error
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ft_sdf_render( FT_Renderer module,
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FT_GlyphSlot slot,
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FT_Render_Mode mode,
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const FT_Vector* origin )
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{
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FT_Error error = FT_Err_Ok;
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FT_Outline* outline = &slot->outline;
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FT_Bitmap* bitmap = &slot->bitmap;
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FT_Memory memory = NULL;
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FT_Renderer render = NULL;
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FT_Pos x_shift = 0;
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FT_Pos y_shift = 0;
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FT_Pos x_pad = 0;
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FT_Pos y_pad = 0;
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SDF_Raster_Params params;
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SDF_Renderer sdf_module = SDF_RENDERER( module );
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render = &sdf_module->root;
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memory = render->root.memory;
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/* check whether slot format is correct before rendering */
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if ( slot->format != render->glyph_format )
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{
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error = FT_THROW( Invalid_Glyph_Format );
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goto Exit;
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}
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/* check whether render mode is correct */
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if ( mode != FT_RENDER_MODE_SDF )
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{
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FT_ERROR(( "[sdf] ft_sdf_render:"
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" sdf module only render when"
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" using `FT_RENDER_MODE_SDF'\n" ));
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error = FT_THROW( Cannot_Render_Glyph );
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goto Exit;
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}
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/* deallocate the previously allocated bitmap */
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if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
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{
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FT_FREE( bitmap->buffer );
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slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
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}
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/* preset the bitmap using the glyph's outline; */
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/* the sdf bitmap is similar to an antialiased bitmap */
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/* with a slightly bigger size and different pixel mode */
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if ( ft_glyphslot_preset_bitmap( slot, FT_RENDER_MODE_NORMAL, origin ) )
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{
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error = FT_THROW( Raster_Overflow );
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goto Exit;
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}
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if ( !bitmap->rows || !bitmap->pitch )
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goto Exit;
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/* the padding will simply be equal to the `spread' */
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x_pad = sdf_module->spread;
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y_pad = sdf_module->spread;
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/* apply the padding; will be in all the directions */
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bitmap->rows += y_pad * 2;
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bitmap->width += x_pad * 2;
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/* ignore the pitch, pixel mode and set custom */
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bitmap->pixel_mode = FT_PIXEL_MODE_GRAY;
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bitmap->pitch = (int)( bitmap->width );
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bitmap->num_grays = 255;
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/* allocate new buffer */
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if ( FT_ALLOC_MULT( bitmap->buffer, bitmap->rows, bitmap->pitch ) )
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goto Exit;
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slot->internal->flags |= FT_GLYPH_OWN_BITMAP;
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x_shift = 64 * -( slot->bitmap_left - x_pad );
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y_shift = 64 * -( slot->bitmap_top + y_pad );
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y_shift += 64 * (FT_Int)bitmap->rows;
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if ( origin )
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{
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x_shift += origin->x;
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y_shift += origin->y;
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}
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/* translate outline to render it into the bitmap */
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if ( x_shift || y_shift )
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FT_Outline_Translate( outline, x_shift, y_shift );
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/* set up parameters */
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params.root.target = bitmap;
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params.root.source = outline;
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params.root.flags = FT_RASTER_FLAG_SDF;
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params.spread = sdf_module->spread;
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params.flip_sign = sdf_module->flip_sign;
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params.flip_y = sdf_module->flip_y;
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params.overlaps = sdf_module->overlaps;
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/* render the outline */
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error = render->raster_render( render->raster,
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(const FT_Raster_Params*)¶ms );
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Exit:
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if ( !error )
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{
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/* the glyph is successfully rendered to a bitmap */
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slot->format = FT_GLYPH_FORMAT_BITMAP;
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}
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else if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
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{
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FT_FREE( bitmap->buffer );
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slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
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}
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if ( x_shift || y_shift )
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FT_Outline_Translate( outline, -x_shift, -y_shift );
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return error;
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}
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/* transform the glyph using matrix and/or delta */
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static FT_Error
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ft_sdf_transform( FT_Renderer render,
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FT_GlyphSlot slot,
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const FT_Matrix* matrix,
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const FT_Vector* delta )
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{
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FT_Error error = FT_Err_Ok;
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if ( slot->format != render->glyph_format )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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if ( matrix )
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FT_Outline_Transform( &slot->outline, matrix );
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if ( delta )
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FT_Outline_Translate( &slot->outline, delta->x, delta->y );
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Exit:
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return error;
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}
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/* return the control box of a glyph's outline */
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static void
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ft_sdf_get_cbox( FT_Renderer render,
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FT_GlyphSlot slot,
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FT_BBox* cbox )
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{
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FT_ZERO( cbox );
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if ( slot->format == render->glyph_format )
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FT_Outline_Get_CBox( &slot->outline, cbox );
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}
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/* set render specific modes or attributes */
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static FT_Error
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ft_sdf_set_mode( FT_Renderer render,
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FT_ULong mode_tag,
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FT_Pointer data )
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{
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/* pass it to the rasterizer */
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return render->clazz->raster_class->raster_set_mode( render->raster,
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mode_tag,
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data );
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}
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FT_DEFINE_RENDERER(
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ft_sdf_renderer_class,
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FT_MODULE_RENDERER,
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sizeof ( SDF_Renderer_Module ),
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"sdf",
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0x10000L,
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0x20000L,
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NULL,
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(FT_Module_Constructor)ft_sdf_init,
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(FT_Module_Destructor) ft_sdf_done,
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(FT_Module_Requester) ft_sdf_requester,
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FT_GLYPH_FORMAT_OUTLINE,
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(FT_Renderer_RenderFunc) ft_sdf_render, /* render_glyph */
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(FT_Renderer_TransformFunc)ft_sdf_transform, /* transform_glyph */
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(FT_Renderer_GetCBoxFunc) ft_sdf_get_cbox, /* get_glyph_cbox */
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(FT_Renderer_SetModeFunc) ft_sdf_set_mode, /* set_mode */
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(FT_Raster_Funcs*)&ft_sdf_raster /* raster_class */
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)
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/*************************************************************************/
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/*************************************************************************/
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/** **/
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/** BITMAP TO SDF CONVERTER **/
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/** **/
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/*************************************************************************/
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/*************************************************************************/
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/* generate signed distance field from glyph's bitmap */
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static FT_Error
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ft_bsdf_render( FT_Renderer module,
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FT_GlyphSlot slot,
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FT_Render_Mode mode,
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const FT_Vector* origin )
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{
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FT_Error error = FT_Err_Ok;
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FT_Memory memory = NULL;
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FT_Bitmap* bitmap = &slot->bitmap;
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FT_Renderer render = NULL;
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FT_Bitmap target;
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FT_Pos x_pad = 0;
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FT_Pos y_pad = 0;
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SDF_Raster_Params params;
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SDF_Renderer sdf_module = SDF_RENDERER( module );
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/* initialize the bitmap in case any error occurs */
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FT_Bitmap_Init( &target );
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render = &sdf_module->root;
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memory = render->root.memory;
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/* check whether slot format is correct before rendering */
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if ( slot->format != render->glyph_format )
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{
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FT_ERROR(( "ft_bsdf_render: slot format must be a bitmap\n" ));
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error = FT_THROW( Invalid_Glyph_Format );
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goto Exit;
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}
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/* check whether render mode is correct */
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if ( mode != FT_RENDER_MODE_SDF )
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{
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FT_ERROR(( "ft_bsdf_render: need `FT_RENDER_MODE_SDF' mode\n" ));
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error = FT_THROW( Cannot_Render_Glyph );
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goto Exit;
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}
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if ( origin )
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{
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FT_ERROR(( "ft_bsdf_render: can't translate the bitmap\n" ));
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error = FT_THROW( Unimplemented_Feature );
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goto Exit;
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}
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if ( !bitmap->rows || !bitmap->pitch )
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goto Exit;
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FT_Bitmap_New( &target );
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/* padding will simply be equal to `spread` */
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x_pad = sdf_module->spread;
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y_pad = sdf_module->spread;
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/* apply padding, which extends to all directions */
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target.rows = bitmap->rows + y_pad * 2;
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target.width = bitmap->width + x_pad * 2;
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/* set up the target bitmap */
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target.pixel_mode = FT_PIXEL_MODE_GRAY;
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target.pitch = (int)( target.width );
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target.num_grays = 255;
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if ( FT_ALLOC_MULT( target.buffer, target.rows, target.pitch ) )
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goto Exit;
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/* set up parameters */
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params.root.target = ⌖
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params.root.source = bitmap;
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params.root.flags = FT_RASTER_FLAG_SDF;
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params.spread = sdf_module->spread;
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params.flip_sign = sdf_module->flip_sign;
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params.flip_y = sdf_module->flip_y;
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error = render->raster_render( render->raster,
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(const FT_Raster_Params*)¶ms );
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Exit:
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if ( !error )
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{
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/* the glyph is successfully converted to a SDF */
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if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP )
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{
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FT_FREE( bitmap->buffer );
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slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP;
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}
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slot->bitmap = target;
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slot->internal->flags |= FT_GLYPH_OWN_BITMAP;
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}
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else if ( target.buffer )
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FT_FREE( target.buffer );
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return error;
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}
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FT_DEFINE_RENDERER(
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ft_bitmap_sdf_renderer_class,
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FT_MODULE_RENDERER,
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sizeof ( SDF_Renderer_Module ),
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"bsdf",
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0x10000L,
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0x20000L,
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NULL,
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(FT_Module_Constructor)ft_sdf_init,
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(FT_Module_Destructor) ft_sdf_done,
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(FT_Module_Requester) ft_sdf_requester,
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FT_GLYPH_FORMAT_BITMAP,
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(FT_Renderer_RenderFunc) ft_bsdf_render, /* render_glyph */
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(FT_Renderer_TransformFunc)ft_sdf_transform, /* transform_glyph */
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(FT_Renderer_GetCBoxFunc) ft_sdf_get_cbox, /* get_glyph_cbox */
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(FT_Renderer_SetModeFunc) ft_sdf_set_mode, /* set_mode */
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(FT_Raster_Funcs*)&ft_bitmap_sdf_raster /* raster_class */
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)
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/* END */
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