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kc3-lang/freetype/src/base/ftbitmap.c
Werner Lemberg
- src/base/ftbitmap.c
-
/***************************************************************************/ /* */ /* ftbitmap.c */ /* */ /* FreeType utility functions for bitmaps (body). */ /* */ /* Copyright 2004-2016 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_BITMAP_H #include FT_IMAGE_H #include FT_INTERNAL_OBJECTS_H static const FT_Bitmap null_bitmap = { 0, 0, 0, 0, 0, 0, 0, 0 }; /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( void ) FT_Bitmap_Init( FT_Bitmap *abitmap ) { if ( abitmap ) *abitmap = null_bitmap; } /* deprecated function name; retained for ABI compatibility */ FT_EXPORT_DEF( void ) FT_Bitmap_New( FT_Bitmap *abitmap ) { if ( abitmap ) *abitmap = null_bitmap; } /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) FT_Bitmap_Copy( FT_Library library, const FT_Bitmap *source, FT_Bitmap *target) { FT_Memory memory; FT_Error error = FT_Err_Ok; FT_Int pitch; FT_ULong size; FT_Int source_pitch_sign, target_pitch_sign; if ( !library ) return FT_THROW( Invalid_Library_Handle ); if ( !source || !target ) return FT_THROW( Invalid_Argument ); if ( source == target ) return FT_Err_Ok; source_pitch_sign = source->pitch < 0 ? -1 : 1; target_pitch_sign = target->pitch < 0 ? -1 : 1; if ( !source->buffer ) { *target = *source; if ( source_pitch_sign != target_pitch_sign ) target->pitch = -target->pitch; return FT_Err_Ok; } memory = library->memory; pitch = source->pitch; if ( pitch < 0 ) pitch = -pitch; size = (FT_ULong)pitch * source->rows; if ( target->buffer ) { FT_Int target_pitch = target->pitch; FT_ULong target_size; if ( target_pitch < 0 ) target_pitch = -target_pitch; target_size = (FT_ULong)target_pitch * target->rows; if ( target_size != size ) (void)FT_QREALLOC( target->buffer, target_size, size ); } else (void)FT_QALLOC( target->buffer, size ); if ( !error ) { unsigned char *p; p = target->buffer; *target = *source; target->buffer = p; if ( source_pitch_sign == target_pitch_sign ) FT_MEM_COPY( target->buffer, source->buffer, size ); else { /* take care of bitmap flow */ FT_UInt i; FT_Byte* s = source->buffer; FT_Byte* t = target->buffer; t += (FT_ULong)pitch * ( target->rows - 1 ); for ( i = target->rows; i > 0; i-- ) { FT_ARRAY_COPY( t, s, pitch ); s += pitch; t -= pitch; } } } return error; } /* Enlarge `bitmap' horizontally and vertically by `xpixels' */ /* and `ypixels', respectively. */ static FT_Error ft_bitmap_assure_buffer( FT_Memory memory, FT_Bitmap* bitmap, FT_UInt xpixels, FT_UInt ypixels ) { FT_Error error; int pitch; int new_pitch; FT_UInt bpp; FT_UInt i, width, height; unsigned char* buffer = NULL; width = bitmap->width; height = bitmap->rows; pitch = bitmap->pitch; if ( pitch < 0 ) pitch = -pitch; switch ( bitmap->pixel_mode ) { case FT_PIXEL_MODE_MONO: bpp = 1; new_pitch = (int)( ( width + xpixels + 7 ) >> 3 ); break; case FT_PIXEL_MODE_GRAY2: bpp = 2; new_pitch = (int)( ( width + xpixels + 3 ) >> 2 ); break; case FT_PIXEL_MODE_GRAY4: bpp = 4; new_pitch = (int)( ( width + xpixels + 1 ) >> 1 ); break; case FT_PIXEL_MODE_GRAY: case FT_PIXEL_MODE_LCD: case FT_PIXEL_MODE_LCD_V: bpp = 8; new_pitch = (int)( width + xpixels ); break; default: return FT_THROW( Invalid_Glyph_Format ); } /* if no need to allocate memory */ if ( ypixels == 0 && new_pitch <= pitch ) { /* zero the padding */ FT_UInt bit_width = (FT_UInt)pitch * 8; FT_UInt bit_last = ( width + xpixels ) * bpp; if ( bit_last < bit_width ) { FT_Byte* line = bitmap->buffer + ( bit_last >> 3 ); FT_Byte* end = bitmap->buffer + pitch; FT_UInt shift = bit_last & 7; FT_UInt mask = 0xFF00U >> shift; FT_UInt count = height; for ( ; count > 0; count--, line += pitch, end += pitch ) { FT_Byte* write = line; if ( shift > 0 ) { write[0] = (FT_Byte)( write[0] & mask ); write++; } if ( write < end ) FT_MEM_ZERO( write, end - write ); } } return FT_Err_Ok; } /* otherwise allocate new buffer */ if ( FT_QALLOC_MULT( buffer, new_pitch, bitmap->rows + ypixels ) ) return error; /* new rows get added at the top of the bitmap, */ /* thus take care of the flow direction */ if ( bitmap->pitch > 0 ) { FT_UInt len = ( width * bpp + 7 ) >> 3; for ( i = 0; i < bitmap->rows; i++ ) FT_MEM_COPY( buffer + (FT_UInt)new_pitch * ( ypixels + i ), bitmap->buffer + (FT_UInt)pitch * i, len ); } else { FT_UInt len = ( width * bpp + 7 ) >> 3; for ( i = 0; i < bitmap->rows; i++ ) FT_MEM_COPY( buffer + (FT_UInt)new_pitch * i, bitmap->buffer + (FT_UInt)pitch * i, len ); } FT_FREE( bitmap->buffer ); bitmap->buffer = buffer; if ( bitmap->pitch < 0 ) new_pitch = -new_pitch; /* set pitch only, width and height are left untouched */ bitmap->pitch = new_pitch; return FT_Err_Ok; } /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) FT_Bitmap_Embolden( FT_Library library, FT_Bitmap* bitmap, FT_Pos xStrength, FT_Pos yStrength ) { FT_Error error; unsigned char* p; FT_Int i, x, pitch; FT_UInt y; FT_Int xstr, ystr; if ( !library ) return FT_THROW( Invalid_Library_Handle ); if ( !bitmap || !bitmap->buffer ) return FT_THROW( Invalid_Argument ); if ( ( ( FT_PIX_ROUND( xStrength ) >> 6 ) > FT_INT_MAX ) || ( ( FT_PIX_ROUND( yStrength ) >> 6 ) > FT_INT_MAX ) ) return FT_THROW( Invalid_Argument ); xstr = (FT_Int)FT_PIX_ROUND( xStrength ) >> 6; ystr = (FT_Int)FT_PIX_ROUND( yStrength ) >> 6; if ( xstr == 0 && ystr == 0 ) return FT_Err_Ok; else if ( xstr < 0 || ystr < 0 ) return FT_THROW( Invalid_Argument ); switch ( bitmap->pixel_mode ) { case FT_PIXEL_MODE_GRAY2: case FT_PIXEL_MODE_GRAY4: { FT_Bitmap tmp; /* convert to 8bpp */ FT_Bitmap_Init( &tmp ); error = FT_Bitmap_Convert( library, bitmap, &tmp, 1 ); if ( error ) return error; FT_Bitmap_Done( library, bitmap ); *bitmap = tmp; } break; case FT_PIXEL_MODE_MONO: if ( xstr > 8 ) xstr = 8; break; case FT_PIXEL_MODE_LCD: xstr *= 3; break; 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, (FT_UInt)xstr, (FT_UInt)ystr ); if ( error ) return error; /* take care of bitmap flow */ pitch = bitmap->pitch; if ( pitch > 0 ) p = bitmap->buffer + pitch * ystr; else { pitch = -pitch; p = bitmap->buffer + (FT_UInt)pitch * ( bitmap->rows - 1 ); } /* for each row */ for ( y = 0; y < bitmap->rows; y++ ) { /* * Horizontally: * * From the last pixel on, make each pixel or'ed with the * `xstr' pixels before it. */ for ( x = pitch - 1; x >= 0; x-- ) { unsigned char tmp; tmp = p[x]; for ( i = 1; i <= xstr; i++ ) { if ( bitmap->pixel_mode == FT_PIXEL_MODE_MONO ) { p[x] |= tmp >> i; /* the maximum value of 8 for `xstr' comes from here */ if ( x > 0 ) p[x] |= p[x - 1] << ( 8 - i ); #if 0 if ( p[x] == 0xFF ) break; #endif } else { if ( x - i >= 0 ) { if ( p[x] + p[x - i] > bitmap->num_grays - 1 ) { p[x] = (unsigned char)( bitmap->num_grays - 1 ); break; } else { p[x] = (unsigned char)( p[x] + p[x - i] ); if ( p[x] == bitmap->num_grays - 1 ) break; } } else break; } } } /* * Vertically: * * Make the above `ystr' rows or'ed with it. */ for ( x = 1; x <= ystr; x++ ) { unsigned char* q; q = p - bitmap->pitch * x; for ( i = 0; i < pitch; i++ ) q[i] |= p[i]; } p += bitmap->pitch; } bitmap->width += (FT_UInt)xstr; bitmap->rows += (FT_UInt)ystr; return FT_Err_Ok; } static FT_Byte ft_gray_for_premultiplied_srgb_bgra( const FT_Byte* bgra ) { FT_UInt a = bgra[3]; FT_UInt l; /* Short-circuit transparent color to avoid division by zero. */ if ( !a ) return 0; /* * 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, applying a gamma of 2.0. * We guarantee 32-bit arithmetic to avoid overflow but the resulting * luminosity fits into 16 bits. * */ l = ( 4732UL /* 0.0722 * 65536 */ * bgra[0] * bgra[0] + 46871UL /* 0.7152 * 65536 */ * bgra[1] * bgra[1] + 13933UL /* 0.2126 * 65536 */ * bgra[2] * bgra[2] ) >> 16; /* * Final transparency can be determined as follows. * * - 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) = a - l * a. * * We still need to undo premultiplication by dividing l by a*a. * */ return (FT_Byte)( a - l / a ); } /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) FT_Bitmap_Convert( FT_Library library, const FT_Bitmap *source, FT_Bitmap *target, FT_Int alignment ) { FT_Error error = FT_Err_Ok; FT_Memory memory; FT_Byte* s; FT_Byte* t; if ( !library ) return FT_THROW( Invalid_Library_Handle ); if ( !source || !target ) return FT_THROW( Invalid_Argument ); memory = library->memory; switch ( source->pixel_mode ) { case FT_PIXEL_MODE_MONO: case FT_PIXEL_MODE_GRAY: case FT_PIXEL_MODE_GRAY2: case FT_PIXEL_MODE_GRAY4: case FT_PIXEL_MODE_LCD: case FT_PIXEL_MODE_LCD_V: case FT_PIXEL_MODE_BGRA: { FT_Int pad, old_target_pitch, target_pitch; FT_ULong old_size; old_target_pitch = target->pitch; if ( old_target_pitch < 0 ) old_target_pitch = -old_target_pitch; old_size = target->rows * (FT_UInt)old_target_pitch; target->pixel_mode = FT_PIXEL_MODE_GRAY; target->rows = source->rows; target->width = source->width; pad = 0; if ( alignment > 0 ) { pad = (FT_Int)source->width % alignment; if ( pad != 0 ) pad = alignment - pad; } target_pitch = (FT_Int)source->width + pad; if ( target_pitch > 0 && (FT_ULong)target->rows > FT_ULONG_MAX / (FT_ULong)target_pitch ) return FT_THROW( Invalid_Argument ); if ( target->rows * (FT_ULong)target_pitch > old_size && FT_QREALLOC( target->buffer, old_size, target->rows * (FT_UInt)target_pitch ) ) return error; target->pitch = target->pitch < 0 ? -target_pitch : target_pitch; } break; default: error = FT_THROW( Invalid_Argument ); } s = source->buffer; t = target->buffer; /* take care of bitmap flow */ if ( source->pitch < 0 ) s -= source->pitch * (FT_Int)( source->rows - 1 ); if ( target->pitch < 0 ) t -= target->pitch * (FT_Int)( target->rows - 1 ); switch ( source->pixel_mode ) { case FT_PIXEL_MODE_MONO: { FT_UInt i; target->num_grays = 2; for ( i = source->rows; i > 0; i-- ) { FT_Byte* ss = s; FT_Byte* tt = t; FT_UInt j; /* get the full bytes */ for ( j = source->width >> 3; j > 0; j-- ) { FT_Int val = ss[0]; /* avoid a byte->int cast on each line */ tt[0] = (FT_Byte)( ( val & 0x80 ) >> 7 ); tt[1] = (FT_Byte)( ( val & 0x40 ) >> 6 ); tt[2] = (FT_Byte)( ( val & 0x20 ) >> 5 ); tt[3] = (FT_Byte)( ( val & 0x10 ) >> 4 ); tt[4] = (FT_Byte)( ( val & 0x08 ) >> 3 ); tt[5] = (FT_Byte)( ( val & 0x04 ) >> 2 ); tt[6] = (FT_Byte)( ( val & 0x02 ) >> 1 ); tt[7] = (FT_Byte)( val & 0x01 ); tt += 8; ss += 1; } /* get remaining pixels (if any) */ j = source->width & 7; if ( j > 0 ) { FT_Int val = *ss; for ( ; j > 0; j-- ) { tt[0] = (FT_Byte)( ( val & 0x80 ) >> 7); val <<= 1; tt += 1; } } s += source->pitch; t += target->pitch; } } break; case FT_PIXEL_MODE_GRAY: case FT_PIXEL_MODE_LCD: case FT_PIXEL_MODE_LCD_V: { FT_UInt width = source->width; FT_UInt i; target->num_grays = 256; for ( i = source->rows; i > 0; i-- ) { FT_ARRAY_COPY( t, s, width ); s += source->pitch; t += target->pitch; } } break; case FT_PIXEL_MODE_GRAY2: { FT_UInt i; target->num_grays = 4; for ( i = source->rows; i > 0; i-- ) { FT_Byte* ss = s; FT_Byte* tt = t; FT_UInt j; /* get the full bytes */ for ( j = source->width >> 2; j > 0; j-- ) { FT_Int val = ss[0]; tt[0] = (FT_Byte)( ( val & 0xC0 ) >> 6 ); tt[1] = (FT_Byte)( ( val & 0x30 ) >> 4 ); tt[2] = (FT_Byte)( ( val & 0x0C ) >> 2 ); tt[3] = (FT_Byte)( ( val & 0x03 ) ); ss += 1; tt += 4; } j = source->width & 3; if ( j > 0 ) { FT_Int val = ss[0]; for ( ; j > 0; j-- ) { tt[0] = (FT_Byte)( ( val & 0xC0 ) >> 6 ); val <<= 2; tt += 1; } } s += source->pitch; t += target->pitch; } } break; case FT_PIXEL_MODE_GRAY4: { FT_UInt i; target->num_grays = 16; for ( i = source->rows; i > 0; i-- ) { FT_Byte* ss = s; FT_Byte* tt = t; FT_UInt j; /* get the full bytes */ for ( j = source->width >> 1; j > 0; j-- ) { FT_Int val = ss[0]; tt[0] = (FT_Byte)( ( val & 0xF0 ) >> 4 ); tt[1] = (FT_Byte)( ( val & 0x0F ) ); ss += 1; tt += 2; } if ( source->width & 1 ) tt[0] = (FT_Byte)( ( ss[0] & 0xF0 ) >> 4 ); s += source->pitch; t += target->pitch; } } break; case FT_PIXEL_MODE_BGRA: { FT_UInt i; target->num_grays = 256; for ( i = source->rows; i > 0; i-- ) { FT_Byte* ss = s; FT_Byte* tt = t; FT_UInt j; for ( j = source->width; j > 0; j-- ) { tt[0] = ft_gray_for_premultiplied_srgb_bgra( ss ); ss += 4; tt += 1; } s += source->pitch; t += target->pitch; } } break; default: ; } return error; } /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) FT_GlyphSlot_Own_Bitmap( FT_GlyphSlot slot ) { if ( slot && slot->format == FT_GLYPH_FORMAT_BITMAP && !( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) ) { FT_Bitmap bitmap; FT_Error error; FT_Bitmap_Init( &bitmap ); error = FT_Bitmap_Copy( slot->library, &slot->bitmap, &bitmap ); if ( error ) return error; slot->bitmap = bitmap; slot->internal->flags |= FT_GLYPH_OWN_BITMAP; } return FT_Err_Ok; } /* documentation is in ftbitmap.h */ FT_EXPORT_DEF( FT_Error ) FT_Bitmap_Done( FT_Library library, FT_Bitmap *bitmap ) { FT_Memory memory; if ( !library ) return FT_THROW( Invalid_Library_Handle ); if ( !bitmap ) return FT_THROW( Invalid_Argument ); memory = library->memory; FT_FREE( bitmap->buffer ); *bitmap = null_bitmap; return FT_Err_Ok; } /* END */