firefox-main/modules/freetype2/src/base/ftlcdfil.c (file symbol)

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/****************************************************************************
*
* ftlcdfil.c
*
* FreeType API for color filtering of subpixel bitmap glyphs (body).
*
* Copyright (C) 2006-2026 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/ftlcdfil.h>
#include <freetype/ftimage.h>
#include <freetype/internal/ftobjs.h>
#ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING
/* add padding sufficient for a 5-tap filter, */
/* which is 2/3 of a pixel */
FT_BASE_DEF( void )
ft_lcd_padding( FT_BBox* cbox,
FT_GlyphSlot slot,
FT_Render_Mode mode )
{
FT_UNUSED( slot );
if ( mode == FT_RENDER_MODE_LCD )
{
cbox->xMin -= 43;
cbox->xMax += 43;
}
else if ( mode == FT_RENDER_MODE_LCD_V )
{
cbox->yMin -= 43;
cbox->yMax += 43;
}
}
/* documentation in ftlcdfil.h */
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdFilterWeights( FT_Library library,
unsigned char *weights )
{
if ( !library )
return FT_THROW( Invalid_Library_Handle );
if ( !weights )
return FT_THROW( Invalid_Argument );
ft_memcpy( library->lcd_weights, weights, FT_LCD_FILTER_FIVE_TAPS );
return FT_Err_Ok;
}
/* documentation in ftlcdfil.h */
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdFilter( FT_Library library,
FT_LcdFilter filter )
{
static const FT_LcdFiveTapFilter default_weights =
{ 0x08, 0x4d, 0x56, 0x4d, 0x08 };
static const FT_LcdFiveTapFilter light_weights =
{ 0x00, 0x55, 0x56, 0x55, 0x00 };
if ( !library )
return FT_THROW( Invalid_Library_Handle );
switch ( filter )
{
case FT_LCD_FILTER_NONE:
ft_memset( library->lcd_weights,
0,
FT_LCD_FILTER_FIVE_TAPS );
break;
case FT_LCD_FILTER_DEFAULT:
ft_memcpy( library->lcd_weights,
default_weights,
FT_LCD_FILTER_FIVE_TAPS );
break;
case FT_LCD_FILTER_LIGHT:
ft_memcpy( library->lcd_weights,
light_weights,
FT_LCD_FILTER_FIVE_TAPS );
break;
default:
return FT_THROW( Invalid_Argument );
}
return FT_Err_Ok;
}
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdGeometry( FT_Library library,
FT_Vector sub[3] )
{
FT_UNUSED( library );
FT_UNUSED( sub );
return FT_THROW( Unimplemented_Feature );
}
#else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */
/* add padding to accommodate outline shifts */
FT_BASE_DEF( void )
ft_lcd_padding( FT_BBox* cbox,
FT_GlyphSlot slot,
FT_Render_Mode mode )
{
FT_Vector* sub = slot->library->lcd_geometry;
if ( mode == FT_RENDER_MODE_LCD )
{
cbox->xMin -= FT_MAX( FT_MAX( sub[0].x, sub[1].x ), sub[2].x );
cbox->xMax -= FT_MIN( FT_MIN( sub[0].x, sub[1].x ), sub[2].x );
cbox->yMin -= FT_MAX( FT_MAX( sub[0].y, sub[1].y ), sub[2].y );
cbox->yMax -= FT_MIN( FT_MIN( sub[0].y, sub[1].y ), sub[2].y );
}
else if ( mode == FT_RENDER_MODE_LCD_V )
{
cbox->xMin -= FT_MAX( FT_MAX( sub[0].y, sub[1].y ), sub[2].y );
cbox->xMax -= FT_MIN( FT_MIN( sub[0].y, sub[1].y ), sub[2].y );
cbox->yMin += FT_MIN( FT_MIN( sub[0].x, sub[1].x ), sub[2].x );
cbox->yMax += FT_MAX( FT_MAX( sub[0].x, sub[1].x ), sub[2].x );
}
}
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdFilterWeights( FT_Library library,
unsigned char *weights )
{
FT_UNUSED( library );
FT_UNUSED( weights );
return FT_THROW( Unimplemented_Feature );
}
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdFilter( FT_Library library,
FT_LcdFilter filter )
{
FT_UNUSED( library );
FT_UNUSED( filter );
return FT_THROW( Unimplemented_Feature );
}
/* documentation in ftlcdfil.h */
FT_EXPORT_DEF( FT_Error )
FT_Library_SetLcdGeometry( FT_Library library,
FT_Vector sub[3] )
{
if ( !library )
return FT_THROW( Invalid_Library_Handle );
if ( !sub )
return FT_THROW( Invalid_Argument );
ft_memcpy( library->lcd_geometry, sub, 3 * sizeof( FT_Vector ) );
return FT_Err_Ok;
}
#endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */
/* END */