+++ /dev/null
-/***************************************************************************/
-/* */
-/* ftlcdfil.c */
-/* */
-/* FreeType API for color filtering of subpixel bitmap glyphs (body). */
-/* */
-/* Copyright 2006-2017 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 <ft2build.h>
-#include FT_INTERNAL_DEBUG_H
-
-#include FT_LCD_FILTER_H
-#include FT_IMAGE_H
-#include FT_INTERNAL_OBJECTS_H
-
-
-#ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING
-
-/* define USE_LEGACY to implement the legacy filter */
-#define USE_LEGACY
-
-#define FT_SHIFTCLAMP( x ) ( x >>= 8, (FT_Byte)( x > 255 ? 255 : x ) )
-
- /* FIR filter used by the default and light filters */
- FT_BASE( void )
- ft_lcd_filter_fir( FT_Bitmap* bitmap,
- FT_Render_Mode mode,
- FT_LcdFiveTapFilter weights )
- {
- FT_UInt width = (FT_UInt)bitmap->width;
- FT_UInt height = (FT_UInt)bitmap->rows;
- FT_Int pitch = bitmap->pitch;
- FT_Byte* origin = bitmap->buffer;
-
-
- /* take care of bitmap flow */
- if ( pitch > 0 )
- origin += pitch * (FT_Int)( height - 1 );
-
- /* horizontal in-place FIR filter */
- if ( mode == FT_RENDER_MODE_LCD && width >= 2 )
- {
- FT_Byte* line = origin;
-
-
- /* `fir' must be at least 32 bit wide, since the sum of */
- /* the values in `weights' can exceed 0xFF */
-
- for ( ; height > 0; height--, line -= pitch )
- {
- FT_UInt fir[5];
- FT_UInt val, xx;
-
-
- val = line[0];
- fir[2] = weights[2] * val;
- fir[3] = weights[3] * val;
- fir[4] = weights[4] * val;
-
- val = line[1];
- fir[1] = fir[2] + weights[1] * val;
- fir[2] = fir[3] + weights[2] * val;
- fir[3] = fir[4] + weights[3] * val;
- fir[4] = weights[4] * val;
-
- for ( xx = 2; xx < width; xx++ )
- {
- val = line[xx];
- fir[0] = fir[1] + weights[0] * val;
- fir[1] = fir[2] + weights[1] * val;
- fir[2] = fir[3] + weights[2] * val;
- fir[3] = fir[4] + weights[3] * val;
- fir[4] = weights[4] * val;
-
- line[xx - 2] = FT_SHIFTCLAMP( fir[0] );
- }
-
- line[xx - 2] = FT_SHIFTCLAMP( fir[1] );
- line[xx - 1] = FT_SHIFTCLAMP( fir[2] );
- }
- }
-
- /* vertical in-place FIR filter */
- else if ( mode == FT_RENDER_MODE_LCD_V && height >= 2 )
- {
- FT_Byte* column = origin;
-
-
- for ( ; width > 0; width--, column++ )
- {
- FT_Byte* col = column;
- FT_UInt fir[5];
- FT_UInt val, yy;
-
-
- val = col[0];
- fir[2] = weights[2] * val;
- fir[3] = weights[3] * val;
- fir[4] = weights[4] * val;
- col -= pitch;
-
- val = col[0];
- fir[1] = fir[2] + weights[1] * val;
- fir[2] = fir[3] + weights[2] * val;
- fir[3] = fir[4] + weights[3] * val;
- fir[4] = weights[4] * val;
- col -= pitch;
-
- for ( yy = 2; yy < height; yy++, col -= pitch )
- {
- val = col[0];
- fir[0] = fir[1] + weights[0] * val;
- fir[1] = fir[2] + weights[1] * val;
- fir[2] = fir[3] + weights[2] * val;
- fir[3] = fir[4] + weights[3] * val;
- fir[4] = weights[4] * val;
-
- col[pitch * 2] = FT_SHIFTCLAMP( fir[0] );
- }
-
- col[pitch * 2] = FT_SHIFTCLAMP( fir[1] );
- col[pitch] = FT_SHIFTCLAMP( fir[2] );
- }
- }
- }
-
-
-#ifdef USE_LEGACY
-
- /* intra-pixel filter used by the legacy filter */
- static void
- _ft_lcd_filter_legacy( FT_Bitmap* bitmap,
- FT_Render_Mode mode,
- FT_Byte* weights )
- {
- FT_UInt width = (FT_UInt)bitmap->width;
- FT_UInt height = (FT_UInt)bitmap->rows;
- FT_Int pitch = bitmap->pitch;
- FT_Byte* origin = bitmap->buffer;
-
- static const unsigned int filters[3][3] =
- {
- { 65538 * 9/13, 65538 * 1/6, 65538 * 1/13 },
- { 65538 * 3/13, 65538 * 4/6, 65538 * 3/13 },
- { 65538 * 1/13, 65538 * 1/6, 65538 * 9/13 }
- };
-
- FT_UNUSED( weights );
-
-
- /* take care of bitmap flow */
- if ( pitch > 0 )
- origin += pitch * (FT_Int)( height - 1 );
-
- /* horizontal in-place intra-pixel filter */
- if ( mode == FT_RENDER_MODE_LCD && width >= 3 )
- {
- FT_Byte* line = origin;
-
-
- for ( ; height > 0; height--, line -= pitch )
- {
- FT_UInt xx;
-
-
- for ( xx = 0; xx < width; xx += 3 )
- {
- FT_UInt r, g, b;
- FT_UInt p;
-
-
- p = line[xx];
- r = filters[0][0] * p;
- g = filters[0][1] * p;
- b = filters[0][2] * p;
-
- p = line[xx + 1];
- r += filters[1][0] * p;
- g += filters[1][1] * p;
- b += filters[1][2] * p;
-
- p = line[xx + 2];
- r += filters[2][0] * p;
- g += filters[2][1] * p;
- b += filters[2][2] * p;
-
- line[xx] = (FT_Byte)( r / 65536 );
- line[xx + 1] = (FT_Byte)( g / 65536 );
- line[xx + 2] = (FT_Byte)( b / 65536 );
- }
- }
- }
- else if ( mode == FT_RENDER_MODE_LCD_V && height >= 3 )
- {
- FT_Byte* column = origin;
-
-
- for ( ; width > 0; width--, column++ )
- {
- FT_Byte* col = column - 2 * pitch;
-
-
- for ( ; height > 0; height -= 3, col -= 3 * pitch )
- {
- FT_UInt r, g, b;
- FT_UInt p;
-
-
- p = col[0];
- r = filters[0][0] * p;
- g = filters[0][1] * p;
- b = filters[0][2] * p;
-
- p = col[pitch];
- r += filters[1][0] * p;
- g += filters[1][1] * p;
- b += filters[1][2] * p;
-
- p = col[pitch * 2];
- r += filters[2][0] * p;
- g += filters[2][1] * p;
- b += filters[2][2] * p;
-
- col[0] = (FT_Byte)( r / 65536 );
- col[pitch] = (FT_Byte)( g / 65536 );
- col[pitch * 2] = (FT_Byte)( b / 65536 );
- }
- }
- }
- }
-
-#endif /* USE_LEGACY */
-
-
- 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 );
- library->lcd_filter_func = ft_lcd_filter_fir;
-
- return FT_Err_Ok;
- }
-
-
- 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:
- library->lcd_filter_func = NULL;
- break;
-
- case FT_LCD_FILTER_DEFAULT:
- ft_memcpy( library->lcd_weights,
- default_weights,
- FT_LCD_FILTER_FIVE_TAPS );
- library->lcd_filter_func = ft_lcd_filter_fir;
- break;
-
- case FT_LCD_FILTER_LIGHT:
- ft_memcpy( library->lcd_weights,
- light_weights,
- FT_LCD_FILTER_FIVE_TAPS );
- library->lcd_filter_func = ft_lcd_filter_fir;
- break;
-
-#ifdef USE_LEGACY
-
- case FT_LCD_FILTER_LEGACY:
- case FT_LCD_FILTER_LEGACY1:
- library->lcd_filter_func = _ft_lcd_filter_legacy;
- break;
-
-#endif
-
- default:
- return FT_THROW( Invalid_Argument );
- }
-
- library->lcd_filter = filter;
-
- return FT_Err_Ok;
- }
-
-#else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */
-
- FT_BASE( void )
- ft_lcd_filter_fir( FT_Bitmap* bitmap,
- FT_Render_Mode mode,
- FT_LcdFiveTapFilter weights )
- {
- FT_UNUSED( bitmap );
- FT_UNUSED( mode );
- FT_UNUSED( weights );
- }
-
-
- 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 );
- }
-
-#endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */
-
-
-/* END */
projects / reactos.git / blobdiff