diff options
Diffstat (limited to 'src/3rdparty/freetype/src/base/ftcalc.c')
| -rw-r--r-- | src/3rdparty/freetype/src/base/ftcalc.c | 194 |
1 files changed, 133 insertions, 61 deletions
diff --git a/src/3rdparty/freetype/src/base/ftcalc.c b/src/3rdparty/freetype/src/base/ftcalc.c index f4ff45f8ef..315dc44185 100644 --- a/src/3rdparty/freetype/src/base/ftcalc.c +++ b/src/3rdparty/freetype/src/base/ftcalc.c @@ -1,35 +1,35 @@ -/***************************************************************************/ -/* */ -/* ftcalc.c */ -/* */ -/* Arithmetic computations (body). */ -/* */ -/* Copyright 1996-2018 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. */ -/* */ -/***************************************************************************/ - - /*************************************************************************/ - /* */ - /* Support for 1-complement arithmetic has been totally dropped in this */ - /* release. You can still write your own code if you need it. */ - /* */ - /*************************************************************************/ - - /*************************************************************************/ - /* */ - /* Implementing basic computation routines. */ - /* */ - /* FT_MulDiv(), FT_MulFix(), FT_DivFix(), FT_RoundFix(), FT_CeilFix(), */ - /* and FT_FloorFix() are declared in freetype.h. */ - /* */ - /*************************************************************************/ +/**************************************************************************** + * + * ftcalc.c + * + * Arithmetic computations (body). + * + * Copyright (C) 1996-2019 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. + * + */ + + /************************************************************************** + * + * Support for 1-complement arithmetic has been totally dropped in this + * release. You can still write your own code if you need it. + * + */ + + /************************************************************************** + * + * Implementing basic computation routines. + * + * FT_MulDiv(), FT_MulFix(), FT_DivFix(), FT_RoundFix(), FT_CeilFix(), + * and FT_FloorFix() are declared in freetype.h. + * + */ #include <ft2build.h> @@ -58,14 +58,14 @@ #endif /* !FT_LONG64 */ - /*************************************************************************/ - /* */ - /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ - /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ - /* messages during execution. */ - /* */ + /************************************************************************** + * + * The macro FT_COMPONENT is used in trace mode. It is an implicit + * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log + * messages during execution. + */ #undef FT_COMPONENT -#define FT_COMPONENT trace_calc +#define FT_COMPONENT calc /* transfer sign, leaving a positive number; */ @@ -516,10 +516,10 @@ #elif 0 /* - * This code is nonportable. See comment below. + * 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. + * 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; @@ -527,22 +527,22 @@ /* - * 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'). + * 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). + * 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. + * 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; @@ -701,8 +701,8 @@ if ( !delta ) return FT_THROW( Invalid_Argument ); /* matrix can't be inverted */ - matrix->xy = - FT_DivFix( matrix->xy, delta ); - matrix->yx = - FT_DivFix( matrix->yx, delta ); + matrix->xy = -FT_DivFix( matrix->xy, delta ); + matrix->yx = -FT_DivFix( matrix->yx, delta ); xx = matrix->xx; yy = matrix->yy; @@ -747,6 +747,76 @@ /* documentation is in ftcalc.h */ + 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; + + + 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 ); + + /* + * 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 ) + return 0; + + if ( maxval > 23170 ) + { + FT_Fixed scale = FT_DivFix( maxval, 23170 ); + + + if ( !FT_DivFix( nonzero_minval, scale ) ) + return 0; /* value range too large */ + + 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 ); + } + 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; + + if ( temp1 == 0 || + temp2 / temp1 > 50 ) + return 0; + + return 1; + } + + + /* documentation is in ftcalc.h */ + FT_BASE_DEF( void ) FT_Vector_Transform_Scaled( FT_Vector* vector, const FT_Matrix* matrix, @@ -913,9 +983,13 @@ FT_Pos out_x, FT_Pos out_y ) { + /* we silently ignore overflow errors since such large values */ + /* lead to even more (harmless) rendering errors later on */ + #ifdef FT_LONG64 - FT_Int64 delta = (FT_Int64)in_x * out_y - (FT_Int64)in_y * out_x; + FT_Int64 delta = SUB_INT64( MUL_INT64( in_x, out_y ), + MUL_INT64( in_y, out_x ) ); return ( delta > 0 ) - ( delta < 0 ); @@ -925,8 +999,6 @@ FT_Int result; - /* we silently ignore overflow errors, since such large values */ - /* lead to even more (harmless) rendering errors later on */ if ( ADD_LONG( FT_ABS( in_x ), FT_ABS( out_y ) ) <= 131071L && ADD_LONG( FT_ABS( in_y ), FT_ABS( out_x ) ) <= 131071L ) { |