ref: aae0f1aff4ae40e65294ef27bdf3f21a173ec574
dir: /src/base/ftbitmap.c/
/***************************************************************************/
/* */
/* ftbitmap.c */
/* */
/* FreeType utility functions for bitmaps (body). */
/* */
/* 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, */
/* 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_New( FT_Bitmap *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 = library->memory;
FT_Error error = FT_Err_Ok;
FT_Int pitch = source->pitch;
FT_ULong size;
if ( source == target )
return FT_Err_Ok;
if ( source->buffer == NULL )
{
*target = *source;
return FT_Err_Ok;
}
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;
FT_MEM_COPY( target->buffer, source->buffer, size );
}
return error;
}
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_Int 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 = ( width + xpixels + 7 ) >> 3;
break;
case FT_PIXEL_MODE_GRAY2:
bpp = 2;
new_pitch = ( width + xpixels + 3 ) >> 2;
break;
case FT_PIXEL_MODE_GRAY4:
bpp = 4;
new_pitch = ( 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 = ( 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_Int bit_width = pitch * 8;
FT_Int 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_Int shift = bit_last & 7;
FT_UInt mask = 0xFF00U >> shift;
FT_Int 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;
}
if ( FT_QALLOC_MULT( buffer, new_pitch, bitmap->rows + ypixels ) )
return error;
if ( bitmap->pitch > 0 )
{
FT_Int len = ( width * bpp + 7 ) >> 3;
for ( i = 0; i < bitmap->rows; i++ )
FT_MEM_COPY( buffer + new_pitch * ( ypixels + i ),
bitmap->buffer + pitch * i, len );
}
else
{
FT_Int len = ( width * bpp + 7 ) >> 3;
for ( i = 0; i < bitmap->rows; i++ )
FT_MEM_COPY( buffer + new_pitch * i,
bitmap->buffer + 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, y, pitch;
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;
FT_Int align;
if ( bitmap->pixel_mode == FT_PIXEL_MODE_GRAY2 )
align = ( bitmap->width + xstr + 3 ) / 4;
else
align = ( bitmap->width + xstr + 1 ) / 2;
FT_Bitmap_New( &tmp );
error = FT_Bitmap_Convert( library, bitmap, &tmp, align );
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, xstr, ystr );
if ( error )
return error;
pitch = bitmap->pitch;
if ( pitch > 0 )
p = bitmap->buffer + pitch * ystr;
else
{
pitch = -pitch;
p = bitmap->buffer + 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 += xstr;
bitmap->rows += ystr;
return FT_Err_Ok;
}
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;
/* Short-circuit transparent color to avoid div-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.
*/
/* 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 )
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;
if ( !library )
return FT_THROW( Invalid_Library_Handle );
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;
FT_Long old_size;
old_size = target->rows * target->pitch;
if ( old_size < 0 )
old_size = -old_size;
target->pixel_mode = FT_PIXEL_MODE_GRAY;
target->rows = source->rows;
target->width = source->width;
pad = 0;
if ( alignment > 0 )
{
pad = source->width % alignment;
if ( pad != 0 )
pad = alignment - pad;
}
target->pitch = source->width + pad;
if ( target->pitch > 0 &&
(FT_ULong)target->rows > FT_ULONG_MAX / target->pitch )
return FT_THROW( Invalid_Argument );
if ( target->rows * target->pitch > old_size &&
FT_QREALLOC( target->buffer,
old_size, target->rows * target->pitch ) )
return error;
}
break;
default:
error = FT_THROW( Invalid_Argument );
}
switch ( source->pixel_mode )
{
case FT_PIXEL_MODE_MONO:
{
FT_Byte* s = source->buffer;
FT_Byte* t = target->buffer;
FT_Int i;
target->num_grays = 2;
for ( i = source->rows; i > 0; i-- )
{
FT_Byte* ss = s;
FT_Byte* tt = t;
FT_Int 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_Int width = source->width;
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_ARRAY_COPY( t, s, width );
s += s_pitch;
t += t_pitch;
}
}
break;
case FT_PIXEL_MODE_GRAY2:
{
FT_Byte* s = source->buffer;
FT_Byte* t = target->buffer;
FT_Int i;
target->num_grays = 4;
for ( i = source->rows; i > 0; i-- )
{
FT_Byte* ss = s;
FT_Byte* tt = t;
FT_Int 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_Byte* s = source->buffer;
FT_Byte* t = target->buffer;
FT_Int i;
target->num_grays = 16;
for ( i = source->rows; i > 0; i-- )
{
FT_Byte* ss = s;
FT_Byte* tt = t;
FT_Int 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_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:
;
}
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_New( &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 */