diff options
Diffstat (limited to 'freetype/src/base/ftbitmap.c')
-rw-r--r-- | freetype/src/base/ftbitmap.c | 113 |
1 files changed, 102 insertions, 11 deletions
diff --git a/freetype/src/base/ftbitmap.c b/freetype/src/base/ftbitmap.c index 84fa32275..975818e14 100644 --- a/freetype/src/base/ftbitmap.c +++ b/freetype/src/base/ftbitmap.c @@ -4,7 +4,7 @@ /* */ /* FreeType utility functions for bitmaps (body). */ /* */ -/* Copyright 2004-2009, 2011 by */ +/* Copyright 2004-2009, 2011, 2013 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ @@ -17,6 +17,8 @@ #include <ft2build.h> +#include FT_INTERNAL_DEBUG_H + #include FT_BITMAP_H #include FT_IMAGE_H #include FT_INTERNAL_OBJECTS_H @@ -135,7 +137,7 @@ new_pitch = ( width + xpixels ); break; default: - return FT_Err_Invalid_Glyph_Format; + return FT_THROW( Invalid_Glyph_Format ); } /* if no need to allocate memory */ @@ -223,14 +225,14 @@ if ( !library ) - return FT_Err_Invalid_Library_Handle; + return FT_THROW( Invalid_Library_Handle ); if ( !bitmap || !bitmap->buffer ) - return FT_Err_Invalid_Argument; + return FT_THROW( Invalid_Argument ); if ( ( ( FT_PIX_ROUND( xStrength ) >> 6 ) > FT_INT_MAX ) || ( ( FT_PIX_ROUND( yStrength ) >> 6 ) > FT_INT_MAX ) ) - return FT_Err_Invalid_Argument; + return FT_THROW( Invalid_Argument ); xstr = (FT_Int)FT_PIX_ROUND( xStrength ) >> 6; ystr = (FT_Int)FT_PIX_ROUND( yStrength ) >> 6; @@ -238,7 +240,7 @@ if ( xstr == 0 && ystr == 0 ) return FT_Err_Ok; else if ( xstr < 0 || ystr < 0 ) - return FT_Err_Invalid_Argument; + return FT_THROW( Invalid_Argument ); switch ( bitmap->pixel_mode ) { @@ -277,6 +279,10 @@ case FT_PIXEL_MODE_LCD_V: ystr *= 3; break; + + case FT_PIXEL_MODE_BGRA: + /* We don't embolden color glyphs. */ + return FT_Err_Ok; } error = ft_bitmap_assure_buffer( library->memory, bitmap, xstr, ystr ); @@ -369,6 +375,59 @@ } + FT_Byte + ft_gray_for_premultiplied_srgb_bgra( const FT_Byte* bgra ) + { + FT_Long a = bgra[3]; + FT_Long b = bgra[0]; + FT_Long g = bgra[1]; + FT_Long r = bgra[2]; + FT_Long l; + + + /* + * Luminosity for sRGB is defined using ~0.2126,0.7152,0.0722 + * coefficients for RGB channels *on the linear colors*. + * A gamma of 2.2 is fair to assume. And then, we need to + * undo the premultiplication too. + * + * http://accessibility.kde.org/hsl-adjusted.php + * + * We do the computation with integers only. + */ + + /* Undo premultification, get the number in a 16.16 form. */ + b = FT_MulDiv( b, 65536, a ); + g = FT_MulDiv( g, 65536, a ); + r = FT_MulDiv( r, 65536, a ); + a = a * 256; + + /* Apply gamma of 2.0 instead of 2.2. */ + b = FT_MulFix( b, b ); + g = FT_MulFix( g, g ); + r = FT_MulFix( r, r ); + + /* Apply coefficients. */ + b = FT_MulFix( b, 4731 /* 0.0722 * 65536 */ ); + g = FT_MulFix( g, 46871 /* 0.7152 * 65536 */ ); + r = FT_MulFix( r, 13933 /* 0.2126 * 65536 */ ); + + l = r + g + b; + + /* + * Final transparency can be determined this way: + * + * - If alpha is zero, we want 0. + * - If alpha is zero and luminosity is zero, we want 255. + * - If alpha is zero and luminosity is one, we want 0. + * + * So the formula is a * (1 - l). + */ + + return (FT_Byte)( FT_MulFix( 65535 - l, a ) >> 8 ); + } + + /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) @@ -382,7 +441,7 @@ if ( !library ) - return FT_Err_Invalid_Library_Handle; + return FT_THROW( Invalid_Library_Handle ); memory = library->memory; @@ -394,6 +453,7 @@ case FT_PIXEL_MODE_GRAY4: case FT_PIXEL_MODE_LCD: case FT_PIXEL_MODE_LCD_V: + case FT_PIXEL_MODE_BGRA: { FT_Int pad; FT_Long old_size; @@ -419,7 +479,7 @@ if ( target->pitch > 0 && (FT_ULong)target->rows > FT_ULONG_MAX / target->pitch ) - return FT_Err_Invalid_Argument; + return FT_THROW( Invalid_Argument ); if ( target->rows * target->pitch > old_size && FT_QREALLOC( target->buffer, @@ -429,7 +489,7 @@ break; default: - error = FT_Err_Invalid_Argument; + error = FT_THROW( Invalid_Argument ); } switch ( source->pixel_mode ) @@ -606,6 +666,37 @@ } break; + case FT_PIXEL_MODE_BGRA: + { + FT_Byte* s = source->buffer; + FT_Byte* t = target->buffer; + FT_Int s_pitch = source->pitch; + FT_Int t_pitch = target->pitch; + FT_Int i; + + + target->num_grays = 256; + + for ( i = source->rows; i > 0; i-- ) + { + FT_Byte* ss = s; + FT_Byte* tt = t; + FT_Int j; + + + for ( j = source->width; j > 0; j-- ) + { + tt[0] = ft_gray_for_premultiplied_srgb_bgra( ss ); + + ss += 4; + tt += 1; + } + + s += s_pitch; + t += t_pitch; + } + } + break; default: ; @@ -650,10 +741,10 @@ if ( !library ) - return FT_Err_Invalid_Library_Handle; + return FT_THROW( Invalid_Library_Handle ); if ( !bitmap ) - return FT_Err_Invalid_Argument; + return FT_THROW( Invalid_Argument ); memory = library->memory; |