diff options
Diffstat (limited to 'src/freetype2/base/ftcalc.c')
| -rw-r--r-- | src/freetype2/base/ftcalc.c | 217 |
1 files changed, 176 insertions, 41 deletions
diff --git a/src/freetype2/base/ftcalc.c b/src/freetype2/base/ftcalc.c index 63aed95..3892fab 100644 --- a/src/freetype2/base/ftcalc.c +++ b/src/freetype2/base/ftcalc.c @@ -4,7 +4,7 @@ /* */ /* Arithmetic computations (body). */ /* */ -/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006 by */ +/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2008 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ @@ -33,10 +33,14 @@ #include <ft2build.h> +#include FT_GLYPH_H #include FT_INTERNAL_CALC_H #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_OBJECTS_H +#ifdef FT_MULFIX_INLINED +#undef FT_MulFix +#endif /* we need to define a 64-bits data type here */ @@ -106,12 +110,12 @@ FT_EXPORT_DEF( FT_Int32 ) FT_Sqrt32( FT_Int32 x ) { - FT_ULong val, root, newroot, mask; + FT_UInt32 val, root, newroot, mask; root = 0; - mask = 0x40000000L; - val = (FT_ULong)x; + mask = (FT_UInt32)0x40000000UL; + val = (FT_UInt32)x; do { @@ -192,15 +196,33 @@ FT_MulFix( FT_Long a, FT_Long b ) { +#ifdef FT_MULFIX_ASSEMBLER + + return FT_MULFIX_ASSEMBLER( a, b ); + +#else + FT_Int s = 1; FT_Long c; - if ( a < 0 ) { a = -a; s = -1; } - if ( b < 0 ) { b = -b; s = -s; } + if ( a < 0 ) + { + a = -a; + s = -1; + } + + if ( b < 0 ) + { + b = -b; + s = -s; + } c = (FT_Long)( ( (FT_Int64)a * b + 0x8000L ) >> 16 ); - return ( s > 0 ) ? c : -c ; + + return ( s > 0 ) ? c : -c; + +#endif /* FT_MULFIX_ASSEMBLER */ } @@ -340,6 +362,7 @@ long s; + /* XXX: this function does not allow 64-bit arguments */ if ( a == 0 || b == c ) return a; @@ -355,12 +378,12 @@ FT_Int64 temp, temp2; - ft_multo64( a, b, &temp ); + ft_multo64( (FT_Int32)a, (FT_Int32)b, &temp ); temp2.hi = 0; temp2.lo = (FT_UInt32)(c >> 1); FT_Add64( &temp, &temp2, &temp ); - a = ft_div64by32( temp.hi, temp.lo, c ); + a = ft_div64by32( temp.hi, temp.lo, (FT_Int32)c ); } else a = 0x7FFFFFFFL; @@ -394,8 +417,8 @@ FT_Int64 temp; - ft_multo64( a, b, &temp ); - a = ft_div64by32( temp.hi, temp.lo, c ); + ft_multo64( (FT_Int32)a, (FT_Int32)b, &temp ); + a = ft_div64by32( temp.hi, temp.lo, (FT_Int32)c ); } else a = 0x7FFFFFFFL; @@ -412,31 +435,18 @@ FT_MulFix( FT_Long a, FT_Long b ) { - /* use inline assembly to speed up things a bit */ - -#if defined( __GNUC__ ) && defined( i386 ) - - FT_Long result; +#ifdef FT_MULFIX_ASSEMBLER + return FT_MULFIX_ASSEMBLER( a, b ); - __asm__ __volatile__ ( - "imul %%edx\n" - "movl %%edx, %%ecx\n" - "sarl $31, %%ecx\n" - "addl $0x8000, %%ecx\n" - "addl %%ecx, %%eax\n" - "adcl $0, %%edx\n" - "shrl $16, %%eax\n" - "shll $16, %%edx\n" - "addl %%edx, %%eax\n" - "mov %%eax, %0\n" - : "=r"(result) - : "a"(a), "d"(b) - : "%ecx" - ); - return result; +#elif 0 -#elif 1 + /* + * This code is nonportable. See comment below. + * + * However, on a platform where right-shift of a signed quantity fills + * the leftmost bits by copying the sign bit, it might be faster. + */ FT_Long sa, sb; FT_ULong ua, ub; @@ -445,6 +455,24 @@ if ( a == 0 || b == 0x10000L ) return a; + /* + * This is a clever way of converting a signed number `a' into its + * absolute value (stored back into `a') and its sign. The sign is + * stored in `sa'; 0 means `a' was positive or zero, and -1 means `a' + * was negative. (Similarly for `b' and `sb'). + * + * Unfortunately, it doesn't work (at least not portably). + * + * It makes the assumption that right-shift on a negative signed value + * fills the leftmost bits by copying the sign bit. This is wrong. + * According to K&R 2nd ed, section `A7.8 Shift Operators' on page 206, + * the result of right-shift of a negative signed value is + * implementation-defined. At least one implementation fills the + * leftmost bits with 0s (i.e., it is exactly the same as an unsigned + * right shift). This means that when `a' is negative, `sa' ends up + * with the value 1 rather than -1. After that, everything else goes + * wrong. + */ sa = ( a >> ( sizeof ( a ) * 8 - 1 ) ); a = ( a ^ sa ) - sa; sb = ( b >> ( sizeof ( b ) * 8 - 1 ) ); @@ -512,13 +540,14 @@ FT_UInt32 q; - s = a; a = FT_ABS(a); - s ^= b; b = FT_ABS(b); + /* XXX: this function does not allow 64-bit arguments */ + s = (FT_Int32)a; a = FT_ABS( a ); + s ^= (FT_Int32)b; b = FT_ABS( b ); if ( b == 0 ) { /* check for division by 0 */ - q = 0x7FFFFFFFL; + q = (FT_UInt32)0x7FFFFFFFL; } else if ( ( a >> 16 ) == 0 ) { @@ -535,7 +564,7 @@ temp2.hi = 0; temp2.lo = (FT_UInt32)( b >> 1 ); FT_Add64( &temp, &temp2, &temp ); - q = ft_div64by32( temp.hi, temp.lo, b ); + q = ft_div64by32( temp.hi, temp.lo, (FT_Int32)b ); } return ( s < 0 ? -(FT_Int32)q : (FT_Int32)q ); @@ -666,6 +695,110 @@ #endif /* FT_LONG64 */ + /* documentation is in ftglyph.h */ + + FT_EXPORT_DEF( void ) + FT_Matrix_Multiply( const FT_Matrix* a, + FT_Matrix *b ) + { + FT_Fixed xx, xy, yx, yy; + + + if ( !a || !b ) + return; + + xx = FT_MulFix( a->xx, b->xx ) + FT_MulFix( a->xy, b->yx ); + xy = FT_MulFix( a->xx, b->xy ) + FT_MulFix( a->xy, b->yy ); + yx = FT_MulFix( a->yx, b->xx ) + FT_MulFix( a->yy, b->yx ); + yy = FT_MulFix( a->yx, b->xy ) + FT_MulFix( a->yy, b->yy ); + + b->xx = xx; b->xy = xy; + b->yx = yx; b->yy = yy; + } + + + /* documentation is in ftglyph.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Matrix_Invert( FT_Matrix* matrix ) + { + FT_Pos delta, xx, yy; + + + if ( !matrix ) + return FT_Err_Invalid_Argument; + + /* compute discriminant */ + delta = FT_MulFix( matrix->xx, matrix->yy ) - + FT_MulFix( matrix->xy, matrix->yx ); + + if ( !delta ) + return FT_Err_Invalid_Argument; /* matrix can't be inverted */ + + matrix->xy = - FT_DivFix( matrix->xy, delta ); + matrix->yx = - FT_DivFix( matrix->yx, delta ); + + xx = matrix->xx; + yy = matrix->yy; + + matrix->xx = FT_DivFix( yy, delta ); + matrix->yy = FT_DivFix( xx, delta ); + + return FT_Err_Ok; + } + + + /* documentation is in ftcalc.h */ + + FT_BASE_DEF( void ) + FT_Matrix_Multiply_Scaled( const FT_Matrix* a, + FT_Matrix *b, + FT_Long scaling ) + { + FT_Fixed xx, xy, yx, yy; + + FT_Long val = 0x10000L * scaling; + + + if ( !a || !b ) + return; + + xx = FT_MulDiv( a->xx, b->xx, val ) + FT_MulDiv( a->xy, b->yx, val ); + xy = FT_MulDiv( a->xx, b->xy, val ) + FT_MulDiv( a->xy, b->yy, val ); + yx = FT_MulDiv( a->yx, b->xx, val ) + FT_MulDiv( a->yy, b->yx, val ); + yy = FT_MulDiv( a->yx, b->xy, val ) + FT_MulDiv( a->yy, b->yy, val ); + + b->xx = xx; b->xy = xy; + b->yx = yx; b->yy = yy; + } + + + /* documentation is in ftcalc.h */ + + FT_BASE_DEF( void ) + FT_Vector_Transform_Scaled( FT_Vector* vector, + const FT_Matrix* matrix, + FT_Long scaling ) + { + FT_Pos xz, yz; + + FT_Long val = 0x10000L * scaling; + + + if ( !vector || !matrix ) + return; + + xz = FT_MulDiv( vector->x, matrix->xx, val ) + + FT_MulDiv( vector->y, matrix->xy, val ); + + yz = FT_MulDiv( vector->x, matrix->yx, val ) + + FT_MulDiv( vector->y, matrix->yy, val ); + + vector->x = xz; + vector->y = yz; + } + + /* documentation is in ftcalc.h */ FT_BASE_DEF( FT_Int32 ) @@ -709,7 +842,7 @@ FT_Pos out_x, FT_Pos out_y ) { - FT_Int result; + FT_Long result; /* avoid overflow on 16-bit system */ /* deal with the trivial cases quickly */ @@ -758,8 +891,9 @@ FT_Int64 z1, z2; - ft_multo64( in_x, out_y, &z1 ); - ft_multo64( in_y, out_x, &z2 ); + /* XXX: this function does not allow 64-bit arguments */ + ft_multo64( (FT_Int32)in_x, (FT_Int32)out_y, &z1 ); + ft_multo64( (FT_Int32)in_y, (FT_Int32)out_x, &z2 ); if ( z1.hi > z2.hi ) result = +1; @@ -775,7 +909,8 @@ #endif } - return result; + /* XXX: only the sign of return value, +1/0/-1 must be used */ + return (FT_Int)result; } |