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authorBo Xu <bo_xu@foxitsoftware.com>2014-12-19 14:29:17 -0800
committerBo Xu <bo_xu@foxitsoftware.com>2014-12-19 15:03:12 -0800
commit4c764f391a4cfb82c81117cf9f249a8598be1cc5 (patch)
tree7d0cc6e2db4182a12ecab5f528c9bfccb4b7df6e /third_party/freetype/src/base/ftcalc.c
parentd44e39279b08c0954f07283b4fb3e7f3e292e4de (diff)
downloadpdfium-4c764f391a4cfb82c81117cf9f249a8598be1cc5.tar.xz
XFA: merge patch from CL 815103002
Update freetype to 2.5.4. Put freetype into third_party directory, cleaning up header files. Previously freetype header files are in core/src/fxge/freetype and core/include/thirdparties. There were also multiple fx_freetype.h. This patch removes the additional Foxit wrapper to make further update easier. Notice, for original freetype source code, the following files are modified and need to be updated accordingly in future update: third_party/freetype/include/config/ftmodule.h third_party/freetype/include/config/ftoption.h BUG=407341 R=thestig@chromium.org Review URL: https://codereview.chromium.org/815103002
Diffstat (limited to 'third_party/freetype/src/base/ftcalc.c')
-rw-r--r--third_party/freetype/src/base/ftcalc.c898
1 files changed, 898 insertions, 0 deletions
diff --git a/third_party/freetype/src/base/ftcalc.c b/third_party/freetype/src/base/ftcalc.c
new file mode 100644
index 0000000000..f3ef8c537b
--- /dev/null
+++ b/third_party/freetype/src/base/ftcalc.c
@@ -0,0 +1,898 @@
+/***************************************************************************/
+/* */
+/* ftcalc.c */
+/* */
+/* Arithmetic computations (body). */
+/* */
+/* Copyright 1996-2006, 2008, 2012-2014 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>
+#include FT_GLYPH_H
+#include FT_TRIGONOMETRY_H
+#include FT_INTERNAL_CALC_H
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_OBJECTS_H
+
+
+#ifdef FT_MULFIX_ASSEMBLER
+#undef FT_MulFix
+#endif
+
+/* we need to emulate a 64-bit data type if a real one isn't available */
+
+#ifndef FT_LONG64
+
+ typedef struct FT_Int64_
+ {
+ FT_UInt32 lo;
+ FT_UInt32 hi;
+
+ } FT_Int64;
+
+#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. */
+ /* */
+#undef FT_COMPONENT
+#define FT_COMPONENT trace_calc
+
+
+ /* transfer sign leaving a positive number */
+#define FT_MOVE_SIGN( x, s ) \
+ FT_BEGIN_STMNT \
+ if ( x < 0 ) \
+ { \
+ x = -x; \
+ s = -s; \
+ } \
+ FT_END_STMNT
+
+ /* The following three functions are available regardless of whether */
+ /* FT_LONG64 is defined. */
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Fixed )
+ FT_RoundFix( FT_Fixed a )
+ {
+ return ( a >= 0 ) ? ( a + 0x8000L ) & ~0xFFFFL
+ : -((-a + 0x8000L ) & ~0xFFFFL );
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Fixed )
+ FT_CeilFix( FT_Fixed a )
+ {
+ return ( a >= 0 ) ? ( a + 0xFFFFL ) & ~0xFFFFL
+ : -((-a + 0xFFFFL ) & ~0xFFFFL );
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Fixed )
+ FT_FloorFix( FT_Fixed a )
+ {
+ return ( a >= 0 ) ? a & ~0xFFFFL
+ : -((-a) & ~0xFFFFL );
+ }
+
+#ifndef FT_MSB
+
+ FT_BASE_DEF ( FT_Int )
+ FT_MSB( FT_UInt32 z )
+ {
+ FT_Int shift = 0;
+
+ /* determine msb bit index in `shift' */
+ if ( z & 0xFFFF0000U )
+ {
+ z >>= 16;
+ shift += 16;
+ }
+ if ( z & 0x0000FF00U )
+ {
+ z >>= 8;
+ shift += 8;
+ }
+ if ( z & 0x000000F0U )
+ {
+ z >>= 4;
+ shift += 4;
+ }
+ if ( z & 0x0000000CU )
+ {
+ z >>= 2;
+ shift += 2;
+ }
+ if ( z & 0x00000002U )
+ {
+ /* z >>= 1; */
+ shift += 1;
+ }
+
+ return shift;
+ }
+
+#endif /* !FT_MSB */
+
+
+ /* documentation is in ftcalc.h */
+
+ FT_BASE_DEF( FT_Fixed )
+ FT_Hypot( FT_Fixed x,
+ FT_Fixed y )
+ {
+ FT_Vector v;
+
+
+ v.x = x;
+ v.y = y;
+
+ return FT_Vector_Length( &v );
+ }
+
+
+#ifdef FT_LONG64
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ FT_MulDiv( FT_Long a,
+ FT_Long b,
+ FT_Long c )
+ {
+ FT_Int s = 1;
+ FT_Long d;
+
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+ FT_MOVE_SIGN( c, s );
+
+ d = (FT_Long)( c > 0 ? ( (FT_Int64)a * b + ( c >> 1 ) ) / c
+ : 0x7FFFFFFFL );
+
+ return ( s > 0 ) ? d : -d;
+ }
+
+
+ /* documentation is in ftcalc.h */
+
+ FT_BASE_DEF( FT_Long )
+ FT_MulDiv_No_Round( FT_Long a,
+ FT_Long b,
+ FT_Long c )
+ {
+ FT_Int s = 1;
+ FT_Long d;
+
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+ FT_MOVE_SIGN( c, s );
+
+ d = (FT_Long)( c > 0 ? (FT_Int64)a * b / c
+ : 0x7FFFFFFFL );
+
+ return ( s > 0 ) ? d : -d;
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ 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;
+
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+
+ c = (FT_Long)( ( (FT_Int64)a * b + 0x8000L ) >> 16 );
+
+ return ( s > 0 ) ? c : -c;
+
+#endif /* FT_MULFIX_ASSEMBLER */
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ FT_DivFix( FT_Long a,
+ FT_Long b )
+ {
+ FT_Int s = 1;
+ FT_Long q;
+
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+
+ q = (FT_Long)( b > 0 ? ( ( (FT_UInt64)a << 16 ) + ( b >> 1 ) ) / b
+ : 0x7FFFFFFFL );
+
+ return ( s < 0 ? -q : q );
+ }
+
+
+#else /* !FT_LONG64 */
+
+
+ static void
+ ft_multo64( FT_UInt32 x,
+ FT_UInt32 y,
+ FT_Int64 *z )
+ {
+ FT_UInt32 lo1, hi1, lo2, hi2, lo, hi, i1, i2;
+
+
+ lo1 = x & 0x0000FFFFU; hi1 = x >> 16;
+ lo2 = y & 0x0000FFFFU; hi2 = y >> 16;
+
+ lo = lo1 * lo2;
+ i1 = lo1 * hi2;
+ i2 = lo2 * hi1;
+ hi = hi1 * hi2;
+
+ /* Check carry overflow of i1 + i2 */
+ i1 += i2;
+ hi += (FT_UInt32)( i1 < i2 ) << 16;
+
+ hi += i1 >> 16;
+ i1 = i1 << 16;
+
+ /* Check carry overflow of i1 + lo */
+ lo += i1;
+ hi += ( lo < i1 );
+
+ z->lo = lo;
+ z->hi = hi;
+ }
+
+
+ static FT_UInt32
+ ft_div64by32( FT_UInt32 hi,
+ FT_UInt32 lo,
+ FT_UInt32 y )
+ {
+ FT_UInt32 r, q;
+ FT_Int i;
+
+
+ if ( hi >= y )
+ return (FT_UInt32)0x7FFFFFFFL;
+
+ /* We shift as many bits as we can into the high register, perform */
+ /* 32-bit division with modulo there, then work through the remaining */
+ /* bits with long division. This optimization is especially noticeable */
+ /* for smaller dividends that barely use the high register. */
+
+ i = 31 - FT_MSB( hi );
+ r = ( hi << i ) | ( lo >> ( 32 - i ) ); lo <<= i; /* left 64-bit shift */
+ q = r / y;
+ r -= q * y; /* remainder */
+
+ i = 32 - i; /* bits remaining in low register */
+ do
+ {
+ q <<= 1;
+ r = ( r << 1 ) | ( lo >> 31 ); lo <<= 1;
+
+ if ( r >= y )
+ {
+ r -= y;
+ q |= 1;
+ }
+ } while ( --i );
+
+ return q;
+ }
+
+
+ static void
+ FT_Add64( FT_Int64* x,
+ FT_Int64* y,
+ FT_Int64 *z )
+ {
+ FT_UInt32 lo, hi;
+
+
+ lo = x->lo + y->lo;
+ hi = x->hi + y->hi + ( lo < x->lo );
+
+ z->lo = lo;
+ z->hi = hi;
+ }
+
+
+ /* The FT_MulDiv function has been optimized thanks to ideas from */
+ /* Graham Asher and Alexei Podtelezhnikov. The trick is to optimize */
+ /* a rather common case when everything fits within 32-bits. */
+ /* */
+ /* We compute 'a*b+c/2', then divide it by 'c' (all positive values). */
+ /* */
+ /* The product of two positive numbers never exceeds the square of */
+ /* its mean values. Therefore, we always avoid the overflow by */
+ /* imposing */
+ /* */
+ /* (a + b) / 2 <= sqrt(X - c/2) , */
+ /* */
+ /* where X = 2^32 - 1, the maximum unsigned 32-bit value, and using */
+ /* unsigned arithmetic. Now we replace `sqrt' with a linear function */
+ /* that is smaller or equal for all values of c in the interval */
+ /* [0;X/2]; it should be equal to sqrt(X) and sqrt(3X/4) at the */
+ /* endpoints. Substituting the linear solution and explicit numbers */
+ /* we get */
+ /* */
+ /* a + b <= 131071.99 - c / 122291.84 . */
+ /* */
+ /* In practice, we should use a faster and even stronger inequality */
+ /* */
+ /* a + b <= 131071 - (c >> 16) */
+ /* */
+ /* or, alternatively, */
+ /* */
+ /* a + b <= 129894 - (c >> 17) . */
+ /* */
+ /* FT_MulFix, on the other hand, is optimized for a small value of */
+ /* the first argument, when the second argument can be much larger. */
+ /* This can be achieved by scaling the second argument and the limit */
+ /* in the above inequalities. For example, */
+ /* */
+ /* a + (b >> 8) <= (131071 >> 4) */
+ /* */
+ /* covers the practical range of use. The actual test below is a bit */
+ /* tighter to avoid the border case overflows. */
+ /* */
+ /* In the case of FT_DivFix, the exact overflow check */
+ /* */
+ /* a << 16 <= X - c/2 */
+ /* */
+ /* is scaled down by 2^16 and we use */
+ /* */
+ /* a <= 65535 - (c >> 17) . */
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ FT_MulDiv( FT_Long a,
+ FT_Long b,
+ FT_Long c )
+ {
+ FT_Int s = 1;
+
+
+ /* XXX: this function does not allow 64-bit arguments */
+ if ( a == 0 || b == c )
+ return a;
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+ FT_MOVE_SIGN( c, s );
+
+ if ( c == 0 )
+ a = 0x7FFFFFFFL;
+
+ else if ( (FT_ULong)a + b <= 129894UL - ( c >> 17 ) )
+ a = ( (FT_ULong)a * b + ( c >> 1 ) ) / c;
+
+ else
+ {
+ FT_Int64 temp, temp2;
+
+
+ ft_multo64( a, b, &temp );
+
+ temp2.hi = 0;
+ temp2.lo = c >> 1;
+
+ FT_Add64( &temp, &temp2, &temp );
+
+ /* last attempt to ditch long division */
+ a = temp.hi == 0 ? temp.lo / c
+ : ft_div64by32( temp.hi, temp.lo, c );
+ }
+
+ return ( s < 0 ? -a : a );
+ }
+
+
+ FT_BASE_DEF( FT_Long )
+ FT_MulDiv_No_Round( FT_Long a,
+ FT_Long b,
+ FT_Long c )
+ {
+ FT_Int s = 1;
+
+
+ if ( a == 0 || b == c )
+ return a;
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+ FT_MOVE_SIGN( c, s );
+
+ if ( c == 0 )
+ a = 0x7FFFFFFFL;
+
+ else if ( (FT_ULong)a + b <= 131071UL )
+ a = (FT_ULong)a * b / c;
+
+ else
+ {
+ FT_Int64 temp;
+
+
+ ft_multo64( a, b, &temp );
+
+ /* last attempt to ditch long division */
+ a = temp.hi == 0 ? temp.lo / c
+ : ft_div64by32( temp.hi, temp.lo, c );
+ }
+
+ return ( s < 0 ? -a : a );
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ FT_MulFix( FT_Long a,
+ FT_Long b )
+ {
+#ifdef FT_MULFIX_ASSEMBLER
+
+ return FT_MULFIX_ASSEMBLER( a, b );
+
+#elif 0
+
+ /*
+ * 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;
+
+
+ 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 ) );
+ b = ( b ^ sb ) - sb;
+
+ ua = (FT_ULong)a;
+ ub = (FT_ULong)b;
+
+ if ( ua + ( ub >> 8 ) <= 8190UL )
+ ua = ( ua * ub + 0x8000U ) >> 16;
+ else
+ {
+ FT_ULong al = ua & 0xFFFFU;
+
+
+ ua = ( ua >> 16 ) * ub + al * ( ub >> 16 ) +
+ ( ( al * ( ub & 0xFFFFU ) + 0x8000U ) >> 16 );
+ }
+
+ sa ^= sb,
+ ua = (FT_ULong)(( ua ^ sa ) - sa);
+
+ return (FT_Long)ua;
+
+#else /* 0 */
+
+ FT_Int s = 1;
+ FT_ULong ua, ub;
+
+
+ if ( a == 0 || b == 0x10000L )
+ return a;
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+
+ ua = (FT_ULong)a;
+ ub = (FT_ULong)b;
+
+ if ( ua + ( ub >> 8 ) <= 8190UL )
+ ua = ( ua * ub + 0x8000UL ) >> 16;
+ else
+ {
+ FT_ULong al = ua & 0xFFFFUL;
+
+
+ ua = ( ua >> 16 ) * ub + al * ( ub >> 16 ) +
+ ( ( al * ( ub & 0xFFFFUL ) + 0x8000UL ) >> 16 );
+ }
+
+ return ( s < 0 ? -(FT_Long)ua : (FT_Long)ua );
+
+#endif /* 0 */
+
+ }
+
+
+ /* documentation is in freetype.h */
+
+ FT_EXPORT_DEF( FT_Long )
+ FT_DivFix( FT_Long a,
+ FT_Long b )
+ {
+ FT_Int s = 1;
+ FT_Long q;
+
+
+ /* XXX: this function does not allow 64-bit arguments */
+
+ FT_MOVE_SIGN( a, s );
+ FT_MOVE_SIGN( b, s );
+
+ if ( b == 0 )
+ {
+ /* check for division by 0 */
+ q = 0x7FFFFFFFL;
+ }
+ else if ( a <= 65535L - ( b >> 17 ) )
+ {
+ /* compute result directly */
+ q = (FT_Long)( ( ( (FT_ULong)a << 16 ) + ( b >> 1 ) ) / b );
+ }
+ else
+ {
+ /* we need more bits; we have to do it by hand */
+ FT_Int64 temp, temp2;
+
+
+ temp.hi = a >> 16;
+ temp.lo = a << 16;
+ temp2.hi = 0;
+ temp2.lo = b >> 1;
+
+ FT_Add64( &temp, &temp2, &temp );
+ q = (FT_Long)ft_div64by32( temp.hi, temp.lo, b );
+ }
+
+ return ( s < 0 ? -q : q );
+ }
+
+
+#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_THROW( Invalid_Argument );
+
+ /* compute discriminant */
+ delta = FT_MulFix( matrix->xx, matrix->yy ) -
+ FT_MulFix( matrix->xy, matrix->yx );
+
+ 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 );
+
+ 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;
+ }
+
+
+#if 0
+
+ /* documentation is in ftcalc.h */
+
+ FT_BASE_DEF( FT_Int32 )
+ FT_SqrtFixed( FT_Int32 x )
+ {
+ FT_UInt32 root, rem_hi, rem_lo, test_div;
+ FT_Int count;
+
+
+ root = 0;
+
+ if ( x > 0 )
+ {
+ rem_hi = 0;
+ rem_lo = x;
+ count = 24;
+ do
+ {
+ rem_hi = ( rem_hi << 2 ) | ( rem_lo >> 30 );
+ rem_lo <<= 2;
+ root <<= 1;
+ test_div = ( root << 1 ) + 1;
+
+ if ( rem_hi >= test_div )
+ {
+ rem_hi -= test_div;
+ root += 1;
+ }
+ } while ( --count );
+ }
+
+ return (FT_Int32)root;
+ }
+
+#endif /* 0 */
+
+
+ /* documentation is in ftcalc.h */
+
+ FT_BASE_DEF( FT_Int )
+ ft_corner_orientation( FT_Pos in_x,
+ FT_Pos in_y,
+ FT_Pos out_x,
+ FT_Pos out_y )
+ {
+ FT_Long result; /* avoid overflow on 16-bit system */
+
+
+ /* deal with the trivial cases quickly */
+ if ( in_y == 0 )
+ {
+ if ( in_x >= 0 )
+ result = out_y;
+ else
+ result = -out_y;
+ }
+ else if ( in_x == 0 )
+ {
+ if ( in_y >= 0 )
+ result = -out_x;
+ else
+ result = out_x;
+ }
+ else if ( out_y == 0 )
+ {
+ if ( out_x >= 0 )
+ result = in_y;
+ else
+ result = -in_y;
+ }
+ else if ( out_x == 0 )
+ {
+ if ( out_y >= 0 )
+ result = -in_x;
+ else
+ result = in_x;
+ }
+ else /* general case */
+ {
+#ifdef FT_LONG64
+
+ FT_Int64 delta = (FT_Int64)in_x * out_y - (FT_Int64)in_y * out_x;
+
+
+ if ( delta == 0 )
+ result = 0;
+ else
+ result = 1 - 2 * ( delta < 0 );
+
+#else
+
+ FT_Int64 z1, 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;
+ else if ( z1.hi < z2.hi )
+ result = -1;
+ else if ( z1.lo > z2.lo )
+ result = +1;
+ else if ( z1.lo < z2.lo )
+ result = -1;
+ else
+ result = 0;
+
+#endif
+ }
+
+ /* XXX: only the sign of return value, +1/0/-1 must be used */
+ return (FT_Int)result;
+ }
+
+
+ /* documentation is in ftcalc.h */
+
+ FT_BASE_DEF( FT_Int )
+ ft_corner_is_flat( FT_Pos in_x,
+ FT_Pos in_y,
+ FT_Pos out_x,
+ FT_Pos out_y )
+ {
+ FT_Pos ax = in_x + out_x;
+ FT_Pos ay = in_y + out_y;
+
+ FT_Pos d_in, d_out, d_hypot;
+
+
+ /* The idea of this function is to compare the length of the */
+ /* hypotenuse with the `in' and `out' length. The `corner' */
+ /* represented by `in' and `out' is flat if the hypotenuse's */
+ /* length isn't too large. */
+ /* */
+ /* 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 */
+ /* other vector, we thus always have a flat corner. */
+ /* */
+ /* hypotenuse */
+ /* x---------------------------x */
+ /* \ / */
+ /* \ / */
+ /* in \ / out */
+ /* \ / */
+ /* o */
+ /* Point */
+
+ d_in = FT_HYPOT( in_x, in_y );
+ d_out = FT_HYPOT( out_x, out_y );
+ d_hypot = FT_HYPOT( ax, ay );
+
+ /* now do a simple length comparison: */
+ /* */
+ /* d_in + d_out < 17/16 d_hypot */
+
+ return ( d_in + d_out - d_hypot ) < ( d_hypot >> 4 );
+ }
+
+
+/* END */