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freetype/src/base/ftoutln.c
Werner Lemberg fbe2fe4c75 Handle some integer overflow run-time errors (#46149, #48979). 
This commit (mainly for 32bit CPUs) is the first of a series of
similar commits to handle known integer overflows.  Basically, all
of them are harmless, since they affect rendering of glyphs only,
not posing security threats.  It is expected that fuzzying will show
up more overflows, to be fixed in due course.

The idea is to mark places where overflows can occur, using macros
that simply cast to unsigned integers, because overflow arithmetic
is well defined in this case.  Doing so suppresses run-time errors
of sanitizers without adding computational overhead.

* include/freetype/internal/ftcalc.h (OVERFLOW_ADD_INT,
OVERFLOW_SUB_INT, OVERFLOW_MUL_INT, OVERFLOW_ADD_LONG,
OVERFLOW_SUB_LONG, OVERFLOW_MUL_LONG): New macros.

* src/base/ftcalc.c (FT_RoundFix, FT_CeilFix, FT_Matrix_Multiply,
FT_Matrix_Multiply_Scaled, FT_Vector_Transform_Scaled,
ft_corner_orientation): Use new macros.

* src/base/ftoutln.c (FT_Outline_Get_Orientation): Use new macros.
2017-05-29 13:29:28 +02:00

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/***************************************************************************/
/* */
/* ftoutln.c */
/* */
/* FreeType outline management (body). */
/* */
/* Copyright 1996-2017 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. */
/* */
/***************************************************************************/
/*************************************************************************/
/* */
/* All functions are declared in freetype.h. */
/* */
/*************************************************************************/
#include <ft2build.h>
#include FT_OUTLINE_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_CALC_H
#include FT_INTERNAL_DEBUG_H
#include FT_TRIGONOMETRY_H
/*************************************************************************/
/* */
/* 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_outline
static
const FT_Outline null_outline = { 0, 0, NULL, NULL, NULL, 0 };
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Decompose( FT_Outline* outline,
const FT_Outline_Funcs* func_interface,
void* user )
{
#undef SCALED
#define SCALED( x ) ( ( (x) < 0 ? -( -(x) << shift ) \
: ( (x) << shift ) ) - delta )
FT_Vector v_last;
FT_Vector v_control;
FT_Vector v_start;
FT_Vector* point;
FT_Vector* limit;
char* tags;
FT_Error error;
FT_Int n; /* index of contour in outline */
FT_UInt first; /* index of first point in contour */
FT_Int tag; /* current point's state */
FT_Int shift;
FT_Pos delta;
if ( !outline )
return FT_THROW( Invalid_Outline );
if ( !func_interface )
return FT_THROW( Invalid_Argument );
shift = func_interface->shift;
delta = func_interface->delta;
first = 0;
for ( n = 0; n < outline->n_contours; n++ )
{
FT_Int last; /* index of last point in contour */
FT_TRACE5(( "FT_Outline_Decompose: Outline %d\n", n ));
last = outline->contours[n];
if ( last < 0 )
goto Invalid_Outline;
limit = outline->points + last;
v_start = outline->points[first];
v_start.x = SCALED( v_start.x );
v_start.y = SCALED( v_start.y );
v_last = outline->points[last];
v_last.x = SCALED( v_last.x );
v_last.y = SCALED( v_last.y );
v_control = v_start;
point = outline->points + first;
tags = outline->tags + first;
tag = FT_CURVE_TAG( tags[0] );
/* A contour cannot start with a cubic control point! */
if ( tag == FT_CURVE_TAG_CUBIC )
goto Invalid_Outline;
/* check first point to determine origin */
if ( tag == FT_CURVE_TAG_CONIC )
{
/* first point is conic control. Yes, this happens. */
if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
{
/* start at last point if it is on the curve */
v_start = v_last;
limit--;
}
else
{
/* if both first and last points are conic, */
/* start at their middle and record its position */
/* for closure */
v_start.x = ( v_start.x + v_last.x ) / 2;
v_start.y = ( v_start.y + v_last.y ) / 2;
/* v_last = v_start; */
}
point--;
tags--;
}
FT_TRACE5(( " move to (%.2f, %.2f)\n",
v_start.x / 64.0, v_start.y / 64.0 ));
error = func_interface->move_to( &v_start, user );
if ( error )
goto Exit;
while ( point < limit )
{
point++;
tags++;
tag = FT_CURVE_TAG( tags[0] );
switch ( tag )
{
case FT_CURVE_TAG_ON: /* emit a single line_to */
{
FT_Vector vec;
vec.x = SCALED( point->x );
vec.y = SCALED( point->y );
FT_TRACE5(( " line to (%.2f, %.2f)\n",
vec.x / 64.0, vec.y / 64.0 ));
error = func_interface->line_to( &vec, user );
if ( error )
goto Exit;
continue;
}
case FT_CURVE_TAG_CONIC: /* consume conic arcs */
v_control.x = SCALED( point->x );
v_control.y = SCALED( point->y );
Do_Conic:
if ( point < limit )
{
FT_Vector vec;
FT_Vector v_middle;
point++;
tags++;
tag = FT_CURVE_TAG( tags[0] );
vec.x = SCALED( point->x );
vec.y = SCALED( point->y );
if ( tag == FT_CURVE_TAG_ON )
{
FT_TRACE5(( " conic to (%.2f, %.2f)"
" with control (%.2f, %.2f)\n",
vec.x / 64.0, vec.y / 64.0,
v_control.x / 64.0, v_control.y / 64.0 ));
error = func_interface->conic_to( &v_control, &vec, user );
if ( error )
goto Exit;
continue;
}
if ( tag != FT_CURVE_TAG_CONIC )
goto Invalid_Outline;
v_middle.x = ( v_control.x + vec.x ) / 2;
v_middle.y = ( v_control.y + vec.y ) / 2;
FT_TRACE5(( " conic to (%.2f, %.2f)"
" with control (%.2f, %.2f)\n",
v_middle.x / 64.0, v_middle.y / 64.0,
v_control.x / 64.0, v_control.y / 64.0 ));
error = func_interface->conic_to( &v_control, &v_middle, user );
if ( error )
goto Exit;
v_control = vec;
goto Do_Conic;
}
FT_TRACE5(( " conic to (%.2f, %.2f)"
" with control (%.2f, %.2f)\n",
v_start.x / 64.0, v_start.y / 64.0,
v_control.x / 64.0, v_control.y / 64.0 ));
error = func_interface->conic_to( &v_control, &v_start, user );
goto Close;
default: /* FT_CURVE_TAG_CUBIC */
{
FT_Vector vec1, vec2;
if ( point + 1 > limit ||
FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
goto Invalid_Outline;
point += 2;
tags += 2;
vec1.x = SCALED( point[-2].x );
vec1.y = SCALED( point[-2].y );
vec2.x = SCALED( point[-1].x );
vec2.y = SCALED( point[-1].y );
if ( point <= limit )
{
FT_Vector vec;
vec.x = SCALED( point->x );
vec.y = SCALED( point->y );
FT_TRACE5(( " cubic to (%.2f, %.2f)"
" with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
vec.x / 64.0, vec.y / 64.0,
vec1.x / 64.0, vec1.y / 64.0,
vec2.x / 64.0, vec2.y / 64.0 ));
error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
if ( error )
goto Exit;
continue;
}
FT_TRACE5(( " cubic to (%.2f, %.2f)"
" with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
v_start.x / 64.0, v_start.y / 64.0,
vec1.x / 64.0, vec1.y / 64.0,
vec2.x / 64.0, vec2.y / 64.0 ));
error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
goto Close;
}
}
}
/* close the contour with a line segment */
FT_TRACE5(( " line to (%.2f, %.2f)\n",
v_start.x / 64.0, v_start.y / 64.0 ));
error = func_interface->line_to( &v_start, user );
Close:
if ( error )
goto Exit;
first = (FT_UInt)last + 1;
}
FT_TRACE5(( "FT_Outline_Decompose: Done\n", n ));
return FT_Err_Ok;
Exit:
FT_TRACE5(( "FT_Outline_Decompose: Error 0x%x\n", error ));
return error;
Invalid_Outline:
return FT_THROW( Invalid_Outline );
}
FT_EXPORT_DEF( FT_Error )
FT_Outline_New_Internal( FT_Memory memory,
FT_UInt numPoints,
FT_Int numContours,
FT_Outline *anoutline )
{
FT_Error error;
if ( !anoutline || !memory )
return FT_THROW( Invalid_Argument );
*anoutline = null_outline;
if ( numContours < 0 ||
(FT_UInt)numContours > numPoints )
return FT_THROW( Invalid_Argument );
if ( numPoints > FT_OUTLINE_POINTS_MAX )
return FT_THROW( Array_Too_Large );
if ( FT_NEW_ARRAY( anoutline->points, numPoints ) ||
FT_NEW_ARRAY( anoutline->tags, numPoints ) ||
FT_NEW_ARRAY( anoutline->contours, numContours ) )
goto Fail;
anoutline->n_points = (FT_Short)numPoints;
anoutline->n_contours = (FT_Short)numContours;
anoutline->flags |= FT_OUTLINE_OWNER;
return FT_Err_Ok;
Fail:
anoutline->flags |= FT_OUTLINE_OWNER;
FT_Outline_Done_Internal( memory, anoutline );
return error;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_New( FT_Library library,
FT_UInt numPoints,
FT_Int numContours,
FT_Outline *anoutline )
{
if ( !library )
return FT_THROW( Invalid_Library_Handle );
return FT_Outline_New_Internal( library->memory, numPoints,
numContours, anoutline );
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Check( FT_Outline* outline )
{
if ( outline )
{
FT_Int n_points = outline->n_points;
FT_Int n_contours = outline->n_contours;
FT_Int end0, end;
FT_Int n;
/* empty glyph? */
if ( n_points == 0 && n_contours == 0 )
return FT_Err_Ok;
/* check point and contour counts */
if ( n_points <= 0 || n_contours <= 0 )
goto Bad;
end0 = end = -1;
for ( n = 0; n < n_contours; n++ )
{
end = outline->contours[n];
/* note that we don't accept empty contours */
if ( end <= end0 || end >= n_points )
goto Bad;
end0 = end;
}
if ( end != n_points - 1 )
goto Bad;
/* XXX: check the tags array */
return FT_Err_Ok;
}
Bad:
return FT_THROW( Invalid_Argument );
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Copy( const FT_Outline* source,
FT_Outline *target )
{
FT_Int is_owner;
if ( !source || !target )
return FT_THROW( Invalid_Outline );
if ( source->n_points != target->n_points ||
source->n_contours != target->n_contours )
return FT_THROW( Invalid_Argument );
if ( source == target )
return FT_Err_Ok;
if ( source->n_points )
{
FT_ARRAY_COPY( target->points, source->points, source->n_points );
FT_ARRAY_COPY( target->tags, source->tags, source->n_points );
}
if ( source->n_contours )
FT_ARRAY_COPY( target->contours, source->contours, source->n_contours );
/* copy all flags, except the `FT_OUTLINE_OWNER' one */
is_owner = target->flags & FT_OUTLINE_OWNER;
target->flags = source->flags;
target->flags &= ~FT_OUTLINE_OWNER;
target->flags |= is_owner;
return FT_Err_Ok;
}
FT_EXPORT_DEF( FT_Error )
FT_Outline_Done_Internal( FT_Memory memory,
FT_Outline* outline )
{
if ( !outline )
return FT_THROW( Invalid_Outline );
if ( !memory )
return FT_THROW( Invalid_Argument );
if ( outline->flags & FT_OUTLINE_OWNER )
{
FT_FREE( outline->points );
FT_FREE( outline->tags );
FT_FREE( outline->contours );
}
*outline = null_outline;
return FT_Err_Ok;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Done( FT_Library library,
FT_Outline* outline )
{
/* check for valid `outline' in FT_Outline_Done_Internal() */
if ( !library )
return FT_THROW( Invalid_Library_Handle );
return FT_Outline_Done_Internal( library->memory, outline );
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( void )
FT_Outline_Get_CBox( const FT_Outline* outline,
FT_BBox *acbox )
{
FT_Pos xMin, yMin, xMax, yMax;
if ( outline && acbox )
{
if ( outline->n_points == 0 )
{
xMin = 0;
yMin = 0;
xMax = 0;
yMax = 0;
}
else
{
FT_Vector* vec = outline->points;
FT_Vector* limit = vec + outline->n_points;
xMin = xMax = vec->x;
yMin = yMax = vec->y;
vec++;
for ( ; vec < limit; vec++ )
{
FT_Pos x, y;
x = vec->x;
if ( x < xMin ) xMin = x;
if ( x > xMax ) xMax = x;
y = vec->y;
if ( y < yMin ) yMin = y;
if ( y > yMax ) yMax = y;
}
}
acbox->xMin = xMin;
acbox->xMax = xMax;
acbox->yMin = yMin;
acbox->yMax = yMax;
}
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( void )
FT_Outline_Translate( const FT_Outline* outline,
FT_Pos xOffset,
FT_Pos yOffset )
{
FT_UShort n;
FT_Vector* vec;
if ( !outline )
return;
vec = outline->points;
for ( n = 0; n < outline->n_points; n++ )
{
vec->x += xOffset;
vec->y += yOffset;
vec++;
}
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( void )
FT_Outline_Reverse( FT_Outline* outline )
{
FT_UShort n;
FT_Int first, last;
if ( !outline )
return;
first = 0;
for ( n = 0; n < outline->n_contours; n++ )
{
last = outline->contours[n];
/* reverse point table */
{
FT_Vector* p = outline->points + first;
FT_Vector* q = outline->points + last;
FT_Vector swap;
while ( p < q )
{
swap = *p;
*p = *q;
*q = swap;
p++;
q--;
}
}
/* reverse tags table */
{
char* p = outline->tags + first;
char* q = outline->tags + last;
while ( p < q )
{
char swap;
swap = *p;
*p = *q;
*q = swap;
p++;
q--;
}
}
first = last + 1;
}
outline->flags ^= FT_OUTLINE_REVERSE_FILL;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Render( FT_Library library,
FT_Outline* outline,
FT_Raster_Params* params )
{
FT_Error error;
FT_Renderer renderer;
FT_ListNode node;
if ( !library )
return FT_THROW( Invalid_Library_Handle );
if ( !outline )
return FT_THROW( Invalid_Outline );
if ( !params )
return FT_THROW( Invalid_Argument );
renderer = library->cur_renderer;
node = library->renderers.head;
params->source = (void*)outline;
error = FT_ERR( Cannot_Render_Glyph );
while ( renderer )
{
error = renderer->raster_render( renderer->raster, params );
if ( !error || FT_ERR_NEQ( error, Cannot_Render_Glyph ) )
break;
/* FT_Err_Cannot_Render_Glyph is returned if the render mode */
/* is unsupported by the current renderer for this glyph image */
/* format */
/* now, look for another renderer that supports the same */
/* format */
renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
&node );
}
return error;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Get_Bitmap( FT_Library library,
FT_Outline* outline,
const FT_Bitmap *abitmap )
{
FT_Raster_Params params;
if ( !abitmap )
return FT_THROW( Invalid_Argument );
/* other checks are delayed to `FT_Outline_Render' */
params.target = abitmap;
params.flags = 0;
if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY ||
abitmap->pixel_mode == FT_PIXEL_MODE_LCD ||
abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
params.flags |= FT_RASTER_FLAG_AA;
return FT_Outline_Render( library, outline, &params );
}
/* documentation is in freetype.h */
FT_EXPORT_DEF( void )
FT_Vector_Transform( FT_Vector* vector,
const FT_Matrix* matrix )
{
FT_Pos xz, yz;
if ( !vector || !matrix )
return;
xz = FT_MulFix( vector->x, matrix->xx ) +
FT_MulFix( vector->y, matrix->xy );
yz = FT_MulFix( vector->x, matrix->yx ) +
FT_MulFix( vector->y, matrix->yy );
vector->x = xz;
vector->y = yz;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( void )
FT_Outline_Transform( const FT_Outline* outline,
const FT_Matrix* matrix )
{
FT_Vector* vec;
FT_Vector* limit;
if ( !outline || !matrix )
return;
vec = outline->points;
limit = vec + outline->n_points;
for ( ; vec < limit; vec++ )
FT_Vector_Transform( vec, matrix );
}
#if 0
#define FT_OUTLINE_GET_CONTOUR( outline, c, first, last ) \
do \
{ \
(first) = ( c > 0 ) ? (outline)->points + \
(outline)->contours[c - 1] + 1 \
: (outline)->points; \
(last) = (outline)->points + (outline)->contours[c]; \
} while ( 0 )
/* Is a point in some contour? */
/* */
/* We treat every point of the contour as if it */
/* it were ON. That is, we allow false positives, */
/* but disallow false negatives. (XXX really?) */
static FT_Bool
ft_contour_has( FT_Outline* outline,
FT_Short c,
FT_Vector* point )
{
FT_Vector* first;
FT_Vector* last;
FT_Vector* a;
FT_Vector* b;
FT_UInt n = 0;
FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
for ( a = first; a <= last; a++ )
{
FT_Pos x;
FT_Int intersect;
b = ( a == last ) ? first : a + 1;
intersect = ( a->y - point->y ) ^ ( b->y - point->y );
/* a and b are on the same side */
if ( intersect >= 0 )
{
if ( intersect == 0 && a->y == point->y )
{
if ( ( a->x <= point->x && b->x >= point->x ) ||
( a->x >= point->x && b->x <= point->x ) )
return 1;
}
continue;
}
x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );
if ( x < point->x )
n++;
else if ( x == point->x )
return 1;
}
return n & 1;
}
static FT_Bool
ft_contour_enclosed( FT_Outline* outline,
FT_UShort c )
{
FT_Vector* first;
FT_Vector* last;
FT_Short i;
FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
for ( i = 0; i < outline->n_contours; i++ )
{
if ( i != c && ft_contour_has( outline, i, first ) )
{
FT_Vector* pt;
for ( pt = first + 1; pt <= last; pt++ )
if ( !ft_contour_has( outline, i, pt ) )
return 0;
return 1;
}
}
return 0;
}
/* This version differs from the public one in that each */
/* part (contour not enclosed in another contour) of the */
/* outline is checked for orientation. This is */
/* necessary for some buggy CJK fonts. */
static FT_Orientation
ft_outline_get_orientation( FT_Outline* outline )
{
FT_Short i;
FT_Vector* first;
FT_Vector* last;
FT_Orientation orient = FT_ORIENTATION_NONE;
first = outline->points;
for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
{
FT_Vector* point;
FT_Vector* xmin_point;
FT_Pos xmin;
last = outline->points + outline->contours[i];
/* skip degenerate contours */
if ( last < first + 2 )
continue;
if ( ft_contour_enclosed( outline, i ) )
continue;
xmin = first->x;
xmin_point = first;
for ( point = first + 1; point <= last; point++ )
{
if ( point->x < xmin )
{
xmin = point->x;
xmin_point = point;
}
}
/* check the orientation of the contour */
{
FT_Vector* prev;
FT_Vector* next;
FT_Orientation o;
prev = ( xmin_point == first ) ? last : xmin_point - 1;
next = ( xmin_point == last ) ? first : xmin_point + 1;
if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
o = FT_ORIENTATION_POSTSCRIPT;
else
o = FT_ORIENTATION_TRUETYPE;
if ( orient == FT_ORIENTATION_NONE )
orient = o;
else if ( orient != o )
return FT_ORIENTATION_NONE;
}
}
return orient;
}
#endif /* 0 */
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_Embolden( FT_Outline* outline,
FT_Pos strength )
{
return FT_Outline_EmboldenXY( outline, strength, strength );
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Error )
FT_Outline_EmboldenXY( FT_Outline* outline,
FT_Pos xstrength,
FT_Pos ystrength )
{
FT_Vector* points;
FT_Int c, first, last;
FT_Int orientation;
if ( !outline )
return FT_THROW( Invalid_Outline );
xstrength /= 2;
ystrength /= 2;
if ( xstrength == 0 && ystrength == 0 )
return FT_Err_Ok;
orientation = FT_Outline_Get_Orientation( outline );
if ( orientation == FT_ORIENTATION_NONE )
{
if ( outline->n_contours )
return FT_THROW( Invalid_Argument );
else
return FT_Err_Ok;
}
points = outline->points;
first = 0;
for ( c = 0; c < outline->n_contours; c++ )
{
FT_Vector in, out, anchor, shift;
FT_Fixed l_in, l_out, l_anchor = 0, l, q, d;
FT_Int i, j, k;
l_in = 0;
last = outline->contours[c];
/* pacify compiler */
in.x = in.y = anchor.x = anchor.y = 0;
/* Counter j cycles though the points; counter i advances only */
/* when points are moved; anchor k marks the first moved point. */
for ( i = last, j = first, k = -1;
j != i && i != k;
j = j < last ? j + 1 : first )
{
if ( j != k )
{
out.x = points[j].x - points[i].x;
out.y = points[j].y - points[i].y;
l_out = (FT_Fixed)FT_Vector_NormLen( &out );
if ( l_out == 0 )
continue;
}
else
{
out = anchor;
l_out = l_anchor;
}
if ( l_in != 0 )
{
if ( k < 0 )
{
k = i;
anchor = in;
l_anchor = l_in;
}
d = FT_MulFix( in.x, out.x ) + FT_MulFix( in.y, out.y );
/* shift only if turn is less than ~160 degrees */
if ( d > -0xF000L )
{
d = d + 0x10000L;
/* shift components along lateral bisector in proper orientation */
shift.x = in.y + out.y;
shift.y = in.x + out.x;
if ( orientation == FT_ORIENTATION_TRUETYPE )
shift.x = -shift.x;
else
shift.y = -shift.y;
/* restrict shift magnitude to better handle collapsing segments */
q = FT_MulFix( out.x, in.y ) - FT_MulFix( out.y, in.x );
if ( orientation == FT_ORIENTATION_TRUETYPE )
q = -q;
l = FT_MIN( l_in, l_out );
/* non-strict inequalities avoid divide-by-zero when q == l == 0 */
if ( FT_MulFix( xstrength, q ) <= FT_MulFix( l, d ) )
shift.x = FT_MulDiv( shift.x, xstrength, d );
else
shift.x = FT_MulDiv( shift.x, l, q );
if ( FT_MulFix( ystrength, q ) <= FT_MulFix( l, d ) )
shift.y = FT_MulDiv( shift.y, ystrength, d );
else
shift.y = FT_MulDiv( shift.y, l, q );
}
else
shift.x = shift.y = 0;
for ( ;
i != j;
i = i < last ? i + 1 : first )
{
points[i].x += xstrength + shift.x;
points[i].y += ystrength + shift.y;
}
}
else
i = j;
in = out;
l_in = l_out;
}
first = last + 1;
}
return FT_Err_Ok;
}
/* documentation is in ftoutln.h */
FT_EXPORT_DEF( FT_Orientation )
FT_Outline_Get_Orientation( FT_Outline* outline )
{
FT_BBox cbox;
FT_Int xshift, yshift;
FT_Vector* points;
FT_Vector v_prev, v_cur;
FT_Int c, n, first;
FT_Pos area = 0;
if ( !outline || outline->n_points <= 0 )
return FT_ORIENTATION_TRUETYPE;
/* We use the nonzero winding rule to find the orientation. */
/* Since glyph outlines behave much more `regular' than arbitrary */
/* cubic or quadratic curves, this test deals with the polygon */
/* only that is spanned up by the control points. */
FT_Outline_Get_CBox( outline, &cbox );
/* Handle collapsed outlines to avoid undefined FT_MSB. */
if ( cbox.xMin == cbox.xMax || cbox.yMin == cbox.yMax )
return FT_ORIENTATION_NONE;
xshift = FT_MSB( (FT_UInt32)( FT_ABS( cbox.xMax ) |
FT_ABS( cbox.xMin ) ) ) - 14;
xshift = FT_MAX( xshift, 0 );
yshift = FT_MSB( (FT_UInt32)( cbox.yMax - cbox.yMin ) ) - 14;
yshift = FT_MAX( yshift, 0 );
points = outline->points;
first = 0;
for ( c = 0; c < outline->n_contours; c++ )
{
FT_Int last = outline->contours[c];
v_prev.x = points[last].x >> xshift;
v_prev.y = points[last].y >> yshift;
for ( n = first; n <= last; n++ )
{
v_cur.x = points[n].x >> xshift;
v_cur.y = points[n].y >> yshift;
area = OVERFLOW_ADD_LONG(
area,
( v_cur.y - v_prev.y ) * ( v_cur.x + v_prev.x ) );
v_prev = v_cur;
}
first = last + 1;
}
if ( area > 0 )
return FT_ORIENTATION_POSTSCRIPT;
else if ( area < 0 )
return FT_ORIENTATION_TRUETYPE;
else
return FT_ORIENTATION_NONE;
}
/* END */
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