freetype2/src/base/ftbitmap.c

617 lines
14 KiB
C

/***************************************************************************/
/* */
/* ftbitmap.c */
/* */
/* FreeType utility functions for converting 1bpp, 2bpp, 4bpp, and 8bpp */
/* bitmaps into 8bpp format (body). */
/* */
/* Copyright 2004, 2005, 2006 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_BITMAP_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 ppb;
FT_Int i;
unsigned char* buffer;
pitch = bitmap->pitch;
if ( pitch < 0 )
pitch = -pitch;
switch ( bitmap->pixel_mode )
{
case FT_PIXEL_MODE_MONO:
ppb = 8;
break;
case FT_PIXEL_MODE_GRAY2:
ppb = 4;
break;
case FT_PIXEL_MODE_GRAY4:
ppb = 2;
break;
case FT_PIXEL_MODE_GRAY:
case FT_PIXEL_MODE_LCD:
case FT_PIXEL_MODE_LCD_V:
ppb = 1;
break;
default:
return FT_Err_Invalid_Glyph_Format;
}
/* if no need to allocate memory */
if ( ypixels == 0 && pitch * ppb >= bitmap->width + xpixels )
{
/* zero the padding */
for ( i = 0; i < bitmap->rows; i++ )
{
unsigned char* last_byte;
int bits = xpixels * ( 8 / ppb );
int mask = 0;
last_byte = bitmap->buffer + i * pitch + ( bitmap->width - 1 ) / ppb;
if ( bits >= 8 )
{
FT_MEM_ZERO( last_byte + 1, bits / 8 );
bits %= 8;
}
if ( bits > 0 )
{
while ( bits-- > 0 )
mask |= 1 << bits;
*last_byte &= ~mask;
}
}
return FT_Err_Ok;
}
new_pitch = ( bitmap->width + xpixels + ppb - 1 ) / ppb;
if ( FT_ALLOC( buffer, new_pitch * ( bitmap->rows + ypixels ) ) )
return error;
if ( bitmap->pitch > 0 )
{
for ( i = 0; i < bitmap->rows; i++ )
FT_MEM_COPY( buffer + new_pitch * ( ypixels + i ),
bitmap->buffer + pitch * i, pitch );
}
else
{
for ( i = 0; i < bitmap->rows; i++ )
FT_MEM_COPY( buffer + new_pitch * i,
bitmap->buffer + pitch * i, pitch );
}
FT_FREE( bitmap->buffer );
bitmap->buffer = buffer;
if ( bitmap->pitch < 0 )
new_pitch = -new_pitch;
/* set pitch only */
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_Err_Invalid_Library_Handle;
if ( !bitmap || !bitmap->buffer )
return FT_Err_Invalid_Argument;
xstr = FT_PIX_ROUND( xStrength ) >> 6;
ystr = FT_PIX_ROUND( yStrength ) >> 6;
if ( xstr == 0 && ystr == 0 )
return FT_Err_Ok;
else if ( xstr < 0 || ystr < 0 )
return FT_Err_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;
}
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;
}
/* 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_Err_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:
{
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->rows * target->pitch > old_size &&
FT_QREALLOC( target->buffer,
old_size, target->rows * target->pitch ) )
return error;
}
break;
default:
error = FT_Err_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:
{
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;
default:
;
}
return error;
}
/* 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_Err_Invalid_Library_Handle;
if ( !bitmap )
return FT_Err_Invalid_Argument;
memory = library->memory;
FT_FREE( bitmap->buffer );
*bitmap = null_bitmap;
return FT_Err_Ok;
}
/* END */