diff -r f9283dc4860d -r 88f2e05288ba misc/libfreetype/src/base/ftlcdfil.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/misc/libfreetype/src/base/ftlcdfil.c Mon Apr 25 01:46:54 2011 +0200 @@ -0,0 +1,376 @@ +/***************************************************************************/ +/* */ +/* ftlcdfil.c */ +/* */ +/* FreeType API for color filtering of subpixel bitmap glyphs (body). */ +/* */ +/* Copyright 2006, 2008, 2009, 2010 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 +#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 + + /* FIR filter used by the default and light filters */ + static void + _ft_lcd_filter_fir( FT_Bitmap* bitmap, + FT_Render_Mode mode, + FT_Library library ) + { + FT_Byte* weights = library->lcd_weights; + FT_UInt width = (FT_UInt)bitmap->width; + FT_UInt height = (FT_UInt)bitmap->rows; + + + /* horizontal in-place FIR filter */ + if ( mode == FT_RENDER_MODE_LCD && width >= 4 ) + { + FT_Byte* line = bitmap->buffer; + + + for ( ; height > 0; height--, line += bitmap->pitch ) + { + FT_UInt fir[5]; + FT_UInt val1, xx; + + + val1 = line[0]; + fir[0] = weights[2] * val1; + fir[1] = weights[3] * val1; + fir[2] = weights[4] * val1; + fir[3] = 0; + fir[4] = 0; + + val1 = line[1]; + fir[0] += weights[1] * val1; + fir[1] += weights[2] * val1; + fir[2] += weights[3] * val1; + fir[3] += weights[4] * val1; + + for ( xx = 2; xx < width; xx++ ) + { + FT_UInt val, pix; + + + val = line[xx]; + pix = fir[0] + weights[0] * val; + fir[0] = fir[1] + weights[1] * val; + fir[1] = fir[2] + weights[2] * val; + fir[2] = fir[3] + weights[3] * val; + fir[3] = weights[4] * val; + + pix >>= 8; + pix |= -( pix >> 8 ); + line[xx - 2] = (FT_Byte)pix; + } + + { + FT_UInt pix; + + + pix = fir[0] >> 8; + pix |= -( pix >> 8 ); + line[xx - 2] = (FT_Byte)pix; + + pix = fir[1] >> 8; + pix |= -( pix >> 8 ); + line[xx - 1] = (FT_Byte)pix; + } + } + } + + /* vertical in-place FIR filter */ + else if ( mode == FT_RENDER_MODE_LCD_V && height >= 4 ) + { + FT_Byte* column = bitmap->buffer; + FT_Int pitch = bitmap->pitch; + + + for ( ; width > 0; width--, column++ ) + { + FT_Byte* col = column; + FT_UInt fir[5]; + FT_UInt val1, yy; + + + val1 = col[0]; + fir[0] = weights[2] * val1; + fir[1] = weights[3] * val1; + fir[2] = weights[4] * val1; + fir[3] = 0; + fir[4] = 0; + col += pitch; + + val1 = col[0]; + fir[0] += weights[1] * val1; + fir[1] += weights[2] * val1; + fir[2] += weights[3] * val1; + fir[3] += weights[4] * val1; + col += pitch; + + for ( yy = 2; yy < height; yy++ ) + { + FT_UInt val, pix; + + + val = col[0]; + pix = fir[0] + weights[0] * val; + fir[0] = fir[1] + weights[1] * val; + fir[1] = fir[2] + weights[2] * val; + fir[2] = fir[3] + weights[3] * val; + fir[3] = weights[4] * val; + + pix >>= 8; + pix |= -( pix >> 8 ); + col[-2 * pitch] = (FT_Byte)pix; + col += pitch; + } + + { + FT_UInt pix; + + + pix = fir[0] >> 8; + pix |= -( pix >> 8 ); + col[-2 * pitch] = (FT_Byte)pix; + + pix = fir[1] >> 8; + pix |= -( pix >> 8 ); + col[-pitch] = (FT_Byte)pix; + } + } + } + } + + +#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_Library library ) + { + FT_UInt width = (FT_UInt)bitmap->width; + FT_UInt height = (FT_UInt)bitmap->rows; + FT_Int pitch = bitmap->pitch; + + static const 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( library ); + + + /* horizontal in-place intra-pixel filter */ + if ( mode == FT_RENDER_MODE_LCD && width >= 3 ) + { + FT_Byte* line = bitmap->buffer; + + + for ( ; height > 0; height--, line += pitch ) + { + FT_UInt xx; + + + for ( xx = 0; xx < width; xx += 3 ) + { + FT_UInt r = 0; + FT_UInt g = 0; + FT_UInt b = 0; + 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 = bitmap->buffer; + + + for ( ; width > 0; width--, column++ ) + { + FT_Byte* col = column; + FT_Byte* col_end = col + height * pitch; + + + for ( ; col < col_end; col += 3 * pitch ) + { + FT_UInt r = 0; + FT_UInt g = 0; + FT_UInt b = 0; + 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[2 * pitch] = (FT_Byte)( b / 65536 ); + } + } + } + } + +#endif /* USE_LEGACY */ + + + FT_EXPORT_DEF( FT_Error ) + FT_Library_SetLcdFilterWeights( FT_Library library, + unsigned char *weights ) + { + if ( !library || !weights ) + return FT_Err_Invalid_Argument; + + ft_memcpy( library->lcd_weights, weights, 5 ); + + return FT_Err_Ok; + } + + + FT_EXPORT_DEF( FT_Error ) + FT_Library_SetLcdFilter( FT_Library library, + FT_LcdFilter filter ) + { + static const FT_Byte light_filter[5] = + { 0x00, 0x55, 0x56, 0x55, 0x00 }; + /* the values here sum up to a value larger than 256, */ + /* providing a cheap gamma correction */ + static const FT_Byte default_filter[5] = + { 0x10, 0x40, 0x70, 0x40, 0x10 }; + + + if ( !library ) + return FT_Err_Invalid_Argument; + + switch ( filter ) + { + case FT_LCD_FILTER_NONE: + library->lcd_filter_func = NULL; + library->lcd_extra = 0; + break; + + case FT_LCD_FILTER_DEFAULT: +#if defined( FT_FORCE_LEGACY_LCD_FILTER ) + + library->lcd_filter_func = _ft_lcd_filter_legacy; + library->lcd_extra = 0; + +#elif defined( FT_FORCE_LIGHT_LCD_FILTER ) + + ft_memcpy( library->lcd_weights, light_filter, 5 ); + library->lcd_filter_func = _ft_lcd_filter_fir; + library->lcd_extra = 2; + +#else + + ft_memcpy( library->lcd_weights, default_filter, 5 ); + library->lcd_filter_func = _ft_lcd_filter_fir; + library->lcd_extra = 2; + +#endif + + break; + + case FT_LCD_FILTER_LIGHT: + ft_memcpy( library->lcd_weights, light_filter, 5 ); + library->lcd_filter_func = _ft_lcd_filter_fir; + library->lcd_extra = 2; + break; + +#ifdef USE_LEGACY + + case FT_LCD_FILTER_LEGACY: + library->lcd_filter_func = _ft_lcd_filter_legacy; + library->lcd_extra = 0; + break; + +#endif + + default: + return FT_Err_Invalid_Argument; + } + + library->lcd_filter = filter; + + return FT_Err_Ok; + } + +#else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ + + FT_EXPORT_DEF( FT_Error ) + FT_Library_SetLcdFilterWeights( FT_Library library, + unsigned char *weights ) + { + FT_UNUSED( library ); + FT_UNUSED( weights ); + + return FT_Err_Unimplemented_Feature; + } + + + FT_EXPORT_DEF( FT_Error ) + FT_Library_SetLcdFilter( FT_Library library, + FT_LcdFilter filter ) + { + FT_UNUSED( library ); + FT_UNUSED( filter ); + + return FT_Err_Unimplemented_Feature; + } + +#endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ + + +/* END */