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Add support for Apple composite glyphs.

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* include/freetype/config/ftoption.h
(TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED): New macro.

* src/truetype/ttgload.c (OVERLAP_COMPOUND, SCALED_COMPONENT_OFFSET,
UNSCALED_COMPONENT_OFFSET): New macros for additional OpenType
glyph loading flags.
(load_truetype_glyph): Implement it.
This commit is contained in:
Werner Lemberg 2002-08-16 12:46:52 +00:00
parent f25ce9d0b3
commit eed446d0d5
3 changed files with 107 additions and 12 deletions
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12
ChangeLog
View File

@ -1,3 +1,15 @@
2002-08-16 George Williams <gww@silcom.com>
Add support for Apple composite glyphs.
* include/freetype/config/ftoption.h
(TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED): New macro.
* src/truetype/ttgload.c (OVERLAP_COMPOUND, SCALED_COMPONENT_OFFSET,
UNSCALED_COMPONENT_OFFSET): New macros for additional OpenType
glyph loading flags.
(load_truetype_glyph): Implement it.
2002-08-16 Werner Lemberg <wl@gnu.org>
* src/cff/cffgload.c (cff_free_glyph_data),

19
include/freetype/config/ftoption.h
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@ -401,6 +401,25 @@ FT_BEGIN_HEADER
#define TT_CONFIG_OPTION_INTERPRETER_SWITCH
/*************************************************************************/
/* */
/* Define TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED to compile the */
/* TrueType glyph loader to use Apple's definition of how to handle */
/* component offsets in composite glyphs. */
/* */
/* Apple and MS disagree on the default behavior of component offsets */
/* in composites. Apple says that they should be scaled by the scale */
/* factors in the transformation matrix (roughly, it's more complex) */
/* while MS says they should not. OpenType defines two bits in the */
/* composite flags array which can be used to disambiguate, but old */
/* fonts will not have them. */
/* */
/* http://partners.adobe.com/asn/developer/opentype/glyf.html */
/* http://fonts.apple.com/TTRefMan/RM06/Chap6glyf.html */
/* */
#undef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
/*************************************************************************/
/*************************************************************************/
/**** ****/

88
src/truetype/ttgload.c
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@ -43,17 +43,19 @@
/* */
/* Composite font flags. */
/* */
#define ARGS_ARE_WORDS 0x001
#define ARGS_ARE_XY_VALUES 0x002
#define ROUND_XY_TO_GRID 0x004
#define WE_HAVE_A_SCALE 0x008
/* reserved 0x010 */
#define MORE_COMPONENTS 0x020
#define WE_HAVE_AN_XY_SCALE 0x040
#define WE_HAVE_A_2X2 0x080
#define WE_HAVE_INSTR 0x100
#define USE_MY_METRICS 0x200
#define ARGS_ARE_WORDS 0x0001
#define ARGS_ARE_XY_VALUES 0x0002
#define ROUND_XY_TO_GRID 0x0004
#define WE_HAVE_A_SCALE 0x0008
/* reserved 0x0010 */
#define MORE_COMPONENTS 0x0020
#define WE_HAVE_AN_XY_SCALE 0x0040
#define WE_HAVE_A_2X2 0x0080
#define WE_HAVE_INSTR 0x0100
#define USE_MY_METRICS 0x0200
#define OVERLAP_COMPOUND 0x0400
#define SCALED_COMPONENT_OFFSET 0x0800
#define UNSCALED_COMPONENT_OFFSET 0x1000
/*************************************************************************/
@ -1005,7 +1007,7 @@
/* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
/* `as is' in the glyph slot (the client application will be */
/* responsible for interpreting this data)... */
/* responsible for interpreting these data)... */
/* */
if ( loader->load_flags & FT_LOAD_NO_RECURSE )
{
@ -1123,6 +1125,68 @@
x = subglyph->arg1;
y = subglyph->arg2;
/* Use a default value dependent on */
/* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED. This is useful for old TT */
/* fonts which don't set the xxx_COMPONENT_OFFSET bit. */
#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
if ( !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) &&
#else
if ( ( subglyph->flags & SCALED_COMPONENT_OFFSET ) &&
#endif
( subglyph->flags & ( WE_HAVE_A_SCALE |
WE_HAVE_AN_XY_SCALE |
WE_HAVE_A_2X2 )) )
{
#if 0
/*************************************************************************/
/* */
/* This algorithm is what Apple documents. But it doesn't work. */
/* */
int a = subglyph->transform.xx > 0 ? subglyph->transform.xx
: -subglyph->transform.xx;
int b = subglyph->transform.yx > 0 ? subglyph->transform.yx
: -subglyph->transform.yx;
int c = subglyph->transform.xy > 0 ? subglyph->transform.xy
: -subglyph->transform.xy;
int d = subglyph->transform.yy > 0 ? subglyph->transform.yy
: -subglyph->transform.yy;
int m = a > b ? a : b;
int n = c > d ? c : d;
if ( a - b <= 33 && a - b >= -33 )
m *= 2;
if ( c - d <= 33 && c - d >= -33 )
n *= 2;
x = FT_MulFix( x, m );
y = FT_MulFix( y, n );
#else /* 0 */
/*************************************************************************/
/* */
/* This algorithm is a guess and works much better than the above. */
/* */
int mac_xscale = FT_SqrtFixed(
FT_MulFix( subglyph->transform.xx,
subglyph->transform.xx ) +
FT_MulFix( subglyph->transform.xy,
subglyph->transform.xy) );
int mac_yscale = FT_SqrtFixed(
FT_MulFix( subglyph->transform.yy,
subglyph->transform.yy ) +
FT_MulFix( subglyph->transform.yx,
subglyph->transform.yx ) );
x = FT_MulFix( x, mac_xscale );
y = FT_MulFix( y, mac_yscale );
#endif /* 0 */
}
if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
{
x = FT_MulFix( x, x_scale );