ref: d898aeddbefdf3ab84a2c89dd04bc9862f351204
dir: /src/base/ftoutln.c/
/***************************************************************************/
/* */
/* ftoutln.c */
/* */
/* FreeType outline management (body). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006 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_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, 0, 0, 0, 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) << 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 || !func_interface )
return FT_Err_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 */
last = outline->contours[n];
limit = outline->points + last;
v_start = outline->points[first];
v_last = outline->points[last];
v_start.x = SCALED( v_start.x ); v_start.y = SCALED( v_start.y );
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--;
}
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 );
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 )
{
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;
error = func_interface->conic_to( &v_control, &v_middle, user );
if ( error )
goto Exit;
v_control = vec;
goto Do_Conic;
}
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 );
error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
if ( error )
goto Exit;
continue;
}
error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
goto Close;
}
}
}
/* close the contour with a line segment */
error = func_interface->line_to( &v_start, user );
Close:
if ( error )
goto Exit;
first = last + 1;
}
return 0;
Exit:
return error;
Invalid_Outline:
return FT_Err_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_Err_Invalid_Argument;
*anoutline = null_outline;
if ( FT_NEW_ARRAY( anoutline->points, numPoints * 2L ) ||
FT_NEW_ARRAY( anoutline->tags, numPoints ) ||
FT_NEW_ARRAY( anoutline->contours, numContours ) )
goto Fail;
anoutline->n_points = (FT_UShort)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_Err_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 0;
/* 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 0;
}
Bad:
return FT_Err_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 ||
source->n_points != target->n_points ||
source->n_contours != target->n_contours )
return FT_Err_Invalid_Argument;
if ( source == target )
return FT_Err_Ok;
FT_ARRAY_COPY( target->points, source->points, source->n_points );
FT_ARRAY_COPY( target->tags, source->tags, source->n_points );
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 ( memory && outline )
{
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;
}
else
return FT_Err_Invalid_Argument;
}
/* 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_Err_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 = outline->points;
if ( !outline )
return;
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;
char swap;
while ( p < q )
{
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_Bool update = 0;
FT_Renderer renderer;
FT_ListNode node;
if ( !library )
return FT_Err_Invalid_Library_Handle;
if ( !outline || !params )
return FT_Err_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_ERROR_BASE( error ) != FT_Err_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 );
update = 1;
}
/* if we changed the current renderer for the glyph image format */
/* we need to select it as the next current one */
if ( !error && update && renderer )
FT_Set_Renderer( library, renderer, 0, 0 );
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_Err_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, ¶ms );
}
/* documentation is in ftoutln.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 % 2 );
}
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 )
{
FT_Vector* points;
FT_Vector v_prev, v_first, v_next, v_cur;
FT_Angle rotate, angle_in, angle_out;
FT_Int c, n, first;
FT_Int orientation;
if ( !outline )
return FT_Err_Invalid_Argument;
strength /= 2;
if ( strength == 0 )
return FT_Err_Ok;
orientation = FT_Outline_Get_Orientation( outline );
if ( orientation == FT_ORIENTATION_NONE )
{
if ( outline->n_contours )
return FT_Err_Invalid_Argument;
else
return FT_Err_Ok;
}
if ( orientation == FT_ORIENTATION_TRUETYPE )
rotate = -FT_ANGLE_PI2;
else
rotate = FT_ANGLE_PI2;
points = outline->points;
first = 0;
for ( c = 0; c < outline->n_contours; c++ )
{
int last = outline->contours[c];
v_first = points[first];
v_prev = points[last];
v_cur = v_first;
for ( n = first; n <= last; n++ )
{
FT_Vector in, out;
FT_Angle angle_diff;
FT_Pos d;
FT_Fixed scale;
if ( n < last )
v_next = points[n + 1];
else
v_next = v_first;
/* compute the in and out vectors */
in.x = v_cur.x - v_prev.x;
in.y = v_cur.y - v_prev.y;
out.x = v_next.x - v_cur.x;
out.y = v_next.y - v_cur.y;
angle_in = FT_Atan2( in.x, in.y );
angle_out = FT_Atan2( out.x, out.y );
angle_diff = FT_Angle_Diff( angle_in, angle_out );
scale = FT_Cos( angle_diff / 2 );
if ( scale < 0x4000L && scale > -0x4000L )
in.x = in.y = 0;
else
{
d = FT_DivFix( strength, scale );
FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate );
}
outline->points[n].x = v_cur.x + strength + in.x;
outline->points[n].y = v_cur.y + strength + in.y;
v_prev = v_cur;
v_cur = v_next;
}
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_Pos xmin = 32768L;
FT_Vector* xmin_point = NULL;
FT_Vector* xmin_first = NULL;
FT_Vector* xmin_last = NULL;
short* contour;
FT_Vector* first;
FT_Vector* last;
FT_Vector* prev;
FT_Vector* next;
if ( !outline || outline->n_points <= 0 )
return FT_ORIENTATION_TRUETYPE;
first = outline->points;
for ( contour = outline->contours;
contour < outline->contours + outline->n_contours;
contour++, first = last + 1 )
{
FT_Vector* point;
FT_Int on_curve;
FT_Int on_curve_count = 0;
FT_Pos tmp_xmin = 32768L;
FT_Vector* tmp_xmin_point = NULL;
last = outline->points + *contour;
/* skip degenerate contours */
if ( last < first + 2 )
continue;
for ( point = first; point <= last; ++point )
{
/* Count on-curve points. If there are less than 3 on-curve */
/* points, just bypass this contour. */
on_curve = outline->tags[point - outline->points] & 1;
on_curve_count += on_curve;
if ( point->x < tmp_xmin && on_curve )
{
tmp_xmin = point->x;
tmp_xmin_point = point;
}
}
if ( on_curve_count > 2 && tmp_xmin < xmin )
{
xmin = tmp_xmin;
xmin_point = tmp_xmin_point;
xmin_first = first;
xmin_last = last;
}
}
if ( !xmin_point )
return FT_ORIENTATION_TRUETYPE;
prev = ( xmin_point == xmin_first ) ? xmin_last : xmin_point - 1;
next = ( xmin_point == xmin_last ) ? xmin_first : xmin_point + 1;
/* Skip off-curve points */
while ( ( outline->tags[prev - outline->points] & 1 ) == 0 )
{
if ( prev == xmin_first )
prev = xmin_last;
else
--prev;
}
while ( ( outline->tags[next - outline->points] & 1 ) == 0 )
{
if ( next == xmin_last )
next = xmin_first;
else
++next;
}
#if 1
{
FT_Pos dx1 = prev->x - xmin_point->x;
FT_Pos dy1 = prev->y - xmin_point->y;
FT_Pos dx2 = next->x - xmin_point->x;
FT_Pos dy2 = next->y - xmin_point->y;
if ( dy1 * dx2 > dy2 * dx1 )
return FT_ORIENTATION_POSTSCRIPT;
else
return FT_ORIENTATION_TRUETYPE;
}
#else /* 0 */
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 ) )
return FT_ORIENTATION_POSTSCRIPT;
else
return FT_ORIENTATION_TRUETYPE;
#endif /* 0 */
}
/* END */