diff options
Diffstat (limited to 'freetype/src/base/fttrigon.c')
| -rw-r--r-- | freetype/src/base/fttrigon.c | 97 |
1 files changed, 34 insertions, 63 deletions
diff --git a/freetype/src/base/fttrigon.c b/freetype/src/base/fttrigon.c index fdf433ab8..52395388b 100644 --- a/freetype/src/base/fttrigon.c +++ b/freetype/src/base/fttrigon.c @@ -4,7 +4,7 @@ /* */ /* FreeType trigonometric functions (body). */ /* */ -/* Copyright 2001, 2002, 2003, 2004, 2005 by */ +/* Copyright 2001-2005, 2012 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ @@ -21,25 +21,30 @@ #include FT_TRIGONOMETRY_H - /* the following is 0.2715717684432231 * 2^30 */ -#define FT_TRIG_COSCALE 0x11616E8EUL +#ifdef FT_LONG64 + typedef FT_INT64 FT_Int64; +#endif + + + /* the Cordic shrink factor 0.607252935008887 * 2^32 */ +#define FT_TRIG_SCALE 0x9B74EDA8UL + + /* the following is 0.607252935008887 * 2^30 */ +#define FT_TRIG_COSCALE 0x26DD3B6AUL /* this table was generated for FT_PI = 180L << 16, i.e. degrees */ #define FT_TRIG_MAX_ITERS 23 static const FT_Fixed - ft_trig_arctan_table[24] = + ft_trig_arctan_table[23] = { - 4157273L, 2949120L, 1740967L, 919879L, 466945L, 234379L, 117304L, - 58666L, 29335L, 14668L, 7334L, 3667L, 1833L, 917L, 458L, 229L, 115L, + 2949120L, 1740967L, 919879L, 466945L, 234379L, 117304L, 58666L, + 29335L, 14668L, 7334L, 3667L, 1833L, 917L, 458L, 229L, 115L, 57L, 29L, 14L, 7L, 4L, 2L, 1L }; - /* the Cordic shrink factor, multiplied by 2^32 */ -#define FT_TRIG_SCALE 1166391785UL /* 0x4585BA38UL */ - -#ifdef FT_CONFIG_HAS_INT64 +#ifdef FT_LONG64 /* multiply a given value by the CORDIC shrink factor */ static FT_Fixed @@ -58,7 +63,7 @@ return ( s >= 0 ) ? val : -val; } -#else /* !FT_CONFIG_HAS_INT64 */ +#else /* !FT_LONG64 */ /* multiply a given value by the CORDIC shrink factor */ static FT_Fixed @@ -72,10 +77,10 @@ val = ( val >= 0 ) ? val : -val; v1 = (FT_UInt32)val >> 16; - v2 = (FT_UInt32)(val & 0xFFFFL); + v2 = (FT_UInt32)( val & 0xFFFFL ); - k1 = (FT_UInt32)FT_TRIG_SCALE >> 16; /* constant */ - k2 = (FT_UInt32)(FT_TRIG_SCALE & 0xFFFFL); /* constant */ + k1 = (FT_UInt32)FT_TRIG_SCALE >> 16; /* constant */ + k2 = (FT_UInt32)( FT_TRIG_SCALE & 0xFFFFL ); /* constant */ hi = k1 * v1; lo1 = k1 * v2 + k2 * v1; /* can't overflow */ @@ -93,7 +98,7 @@ return ( s >= 0 ) ? val : -val; } -#endif /* !FT_CONFIG_HAS_INT64 */ +#endif /* !FT_LONG64 */ static FT_Int @@ -209,25 +214,9 @@ theta -= FT_ANGLE_PI; } - /* Initial pseudorotation, with left shift */ arctanptr = ft_trig_arctan_table; - if ( theta < 0 ) - { - xtemp = x + ( y << 1 ); - y = y - ( x << 1 ); - x = xtemp; - theta += *arctanptr++; - } - else - { - xtemp = x - ( y << 1 ); - y = y + ( x << 1 ); - x = xtemp; - theta -= *arctanptr++; - } - - /* Subsequent pseudorotations, with right shifts */ + /* Pseudorotations, with right shifts */ i = 0; do { @@ -255,9 +244,9 @@ static void ft_trig_pseudo_polarize( FT_Vector* vec ) { - FT_Fixed theta; - FT_Fixed yi, i; - FT_Fixed x, y; + FT_Angle theta; + FT_Int i; + FT_Fixed x, y, xtemp; const FT_Fixed *arctanptr; @@ -278,41 +267,23 @@ arctanptr = ft_trig_arctan_table; - if ( y < 0 ) - { - /* Rotate positive */ - yi = y + ( x << 1 ); - x = x - ( y << 1 ); - y = yi; - theta -= *arctanptr++; /* Subtract angle */ - } - else - { - /* Rotate negative */ - yi = y - ( x << 1 ); - x = x + ( y << 1 ); - y = yi; - theta += *arctanptr++; /* Add angle */ - } - + /* Pseudorotations, with right shifts */ i = 0; do { - if ( y < 0 ) + if ( y > 0 ) { - /* Rotate positive */ - yi = y + ( x >> i ); - x = x - ( y >> i ); - y = yi; - theta -= *arctanptr++; + xtemp = x + ( y >> i ); + y = y - ( x >> i ); + x = xtemp; + theta += *arctanptr++; } else { - /* Rotate negative */ - yi = y - ( x >> i ); - x = x + ( y >> i ); - y = yi; - theta += *arctanptr++; + xtemp = x - ( y >> i ); + y = y + ( x >> i ); + x = xtemp; + theta -= *arctanptr++; } } while ( ++i < FT_TRIG_MAX_ITERS ); |