diff options
Diffstat (limited to 'src/3rdparty/freetype/src/base/ftcalc.c')
| -rw-r--r-- | src/3rdparty/freetype/src/base/ftcalc.c | 86 |
1 files changed, 29 insertions, 57 deletions
diff --git a/src/3rdparty/freetype/src/base/ftcalc.c b/src/3rdparty/freetype/src/base/ftcalc.c index 13e74f3353..c5bc7e3b14 100644 --- a/src/3rdparty/freetype/src/base/ftcalc.c +++ b/src/3rdparty/freetype/src/base/ftcalc.c @@ -749,65 +749,43 @@ FT_BASE_DEF( FT_Bool ) FT_Matrix_Check( const FT_Matrix* matrix ) { - FT_Matrix m; - FT_Fixed val[4]; - FT_Fixed nonzero_minval, maxval; - FT_Fixed temp1, temp2; - FT_UInt i; + FT_Fixed xx, xy, yx, yy; + FT_Fixed val; + FT_Int shift; + FT_ULong temp1, temp2; if ( !matrix ) return 0; - val[0] = FT_ABS( matrix->xx ); - val[1] = FT_ABS( matrix->xy ); - val[2] = FT_ABS( matrix->yx ); - val[3] = FT_ABS( matrix->yy ); + xx = matrix->xx; + xy = matrix->xy; + yx = matrix->yx; + yy = matrix->yy; + val = FT_ABS( xx ) | FT_ABS( xy ) | FT_ABS( yx ) | FT_ABS( yy ); - /* - * To avoid overflow, we ensure that each value is not larger than - * - * int(sqrt(2^31 / 4)) = 23170 ; - * - * we also check that no value becomes zero if we have to scale. - */ - - maxval = 0; - nonzero_minval = FT_LONG_MAX; - - for ( i = 0; i < 4; i++ ) - { - if ( val[i] > maxval ) - maxval = val[i]; - if ( val[i] && val[i] < nonzero_minval ) - nonzero_minval = val[i]; - } - - /* we only handle 32bit values */ - if ( maxval > 0x7FFFFFFFL ) + /* we only handle non-zero 32-bit values */ + if ( !val || val > 0x7FFFFFFFL ) return 0; - if ( maxval > 23170 ) - { - FT_Fixed scale = FT_DivFix( maxval, 23170 ); - + /* Scale matrix to avoid the temp1 overflow, which is */ + /* more stringent than avoiding the temp2 overflow. */ - if ( !FT_DivFix( nonzero_minval, scale ) ) - return 0; /* value range too large */ + shift = FT_MSB( val ) - 12; - m.xx = FT_DivFix( matrix->xx, scale ); - m.xy = FT_DivFix( matrix->xy, scale ); - m.yx = FT_DivFix( matrix->yx, scale ); - m.yy = FT_DivFix( matrix->yy, scale ); + if ( shift > 0 ) + { + xx >>= shift; + xy >>= shift; + yx >>= shift; + yy >>= shift; } - else - m = *matrix; - temp1 = FT_ABS( m.xx * m.yy - m.xy * m.yx ); - temp2 = m.xx * m.xx + m.xy * m.xy + m.yx * m.yx + m.yy * m.yy; + temp1 = 32U * (FT_ULong)FT_ABS( xx * yy - xy * yx ); + temp2 = (FT_ULong)( xx * xx ) + (FT_ULong)( xy * xy ) + + (FT_ULong)( yx * yx ) + (FT_ULong)( yy * yy ); - if ( temp1 == 0 || - temp2 / temp1 > 50 ) + if ( temp1 <= temp2 ) return 0; return 1; @@ -1061,7 +1039,7 @@ /* */ /* This approach has the advantage that the angle between */ /* `in' and `out' is not checked. In case one of the two */ - /* vectors is `dominant', this is, much larger than the */ + /* vectors is `dominant', that is, much larger than the */ /* other vector, we thus always have a flat corner. */ /* */ /* hypotenuse */ @@ -1092,9 +1070,6 @@ { FT_UInt i; FT_Int64 temp; -#ifndef FT_INT64 - FT_Int64 halfUnit; -#endif #ifdef FT_INT64 @@ -1103,7 +1078,7 @@ for ( i = 0; i < count; ++i ) temp += (FT_Int64)s[i] * f[i]; - return ( temp + 0x8000 ) >> 16; + return (FT_Int32)( ( temp + 0x8000 ) >> 16 ); #else temp.hi = 0; temp.lo = 0; @@ -1139,13 +1114,10 @@ FT_Add64( &temp, &multResult, &temp ); } - /* Round value. */ - halfUnit.hi = 0; - halfUnit.lo = 0x8000; - FT_Add64( &temp, &halfUnit, &temp ); + /* Shift and round value. */ + return (FT_Int32)( ( ( temp.hi << 16 ) | ( temp.lo >> 16 ) ) + + ( 1 & ( temp.lo >> 15 ) ) ); - return (FT_Int32)( ( (FT_Int32)( temp.hi & 0xFFFF ) << 16 ) | - ( temp.lo >> 16 ) ); #endif /* !FT_INT64 */ |