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src/java.desktop/share/native/libfreetype/src/base/ftstroke.c
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@@ -2,11 +2,11 @@
*
* ftstroke.c
*
* FreeType path stroker (body).
*
- * Copyright (C) 2002-2019 by
+ * Copyright (C) 2002-2020 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
@@ -538,67 +538,56 @@
FT_Vector* center,
FT_Fixed radius,
FT_Angle angle_start,
FT_Angle angle_diff )
{
- FT_Angle total, angle, step, rotate, next, theta;
- FT_Vector a, b, a2, b2;
- FT_Fixed length;
+ FT_Fixed coef;
+ FT_Vector a0, a1, a2, a3;
+ FT_Int i, arcs = 1;
FT_Error error = FT_Err_Ok;
- /* compute start point */
- FT_Vector_From_Polar( &a, radius, angle_start );
- a.x += center->x;
- a.y += center->y;
-
- total = angle_diff;
- angle = angle_start;
- rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2;
-
- while ( total != 0 )
- {
- step = total;
- if ( step > FT_ARC_CUBIC_ANGLE )
- step = FT_ARC_CUBIC_ANGLE;
-
- else if ( step < -FT_ARC_CUBIC_ANGLE )
- step = -FT_ARC_CUBIC_ANGLE;
-
- next = angle + step;
- theta = step;
- if ( theta < 0 )
- theta = -theta;
-
- theta >>= 1;
-
- /* compute end point */
- FT_Vector_From_Polar( &b, radius, next );
- b.x += center->x;
- b.y += center->y;
-
- /* compute first and second control points */
- length = FT_MulDiv( radius, FT_Sin( theta ) * 4,
- ( 0x10000L + FT_Cos( theta ) ) * 3 );
-
- FT_Vector_From_Polar( &a2, length, angle + rotate );
- a2.x += a.x;
- a2.y += a.y;
-
- FT_Vector_From_Polar( &b2, length, next - rotate );
- b2.x += b.x;
- b2.y += b.y;
+ /* number of cubic arcs to draw */
+ while ( angle_diff > FT_ARC_CUBIC_ANGLE * arcs ||
+ -angle_diff > FT_ARC_CUBIC_ANGLE * arcs )
+ arcs++;
+
+ /* control tangents */
+ coef = FT_Tan( angle_diff / ( 4 * arcs ) );
+ coef += coef / 3;
+
+ /* compute start and first control point */
+ FT_Vector_From_Polar( &a0, radius, angle_start );
+ a1.x = FT_MulFix( -a0.y, coef );
+ a1.y = FT_MulFix( a0.x, coef );
+
+ a0.x += center->x;
+ a0.y += center->y;
+ a1.x += a0.x;
+ a1.y += a0.y;
+
+ for ( i = 1; i <= arcs; i++ )
+ {
+ /* compute end and second control point */
+ FT_Vector_From_Polar( &a3, radius,
+ angle_start + i * angle_diff / arcs );
+ a2.x = FT_MulFix( a3.y, coef );
+ a2.y = FT_MulFix( -a3.x, coef );
+
+ a3.x += center->x;
+ a3.y += center->y;
+ a2.x += a3.x;
+ a2.y += a3.y;
/* add cubic arc */
- error = ft_stroke_border_cubicto( border, &a2, &b2, &b );
+ error = ft_stroke_border_cubicto( border, &a1, &a2, &a3 );
if ( error )
break;
- /* process the rest of the arc ?? */
- a = b;
- total -= step;
- angle = next;
+ /* a0 = a3; */
+ a1.x = a3.x - a2.x + a3.x;
+ a1.y = a3.y - a2.y + a3.y;
}
return error;
}
@@ -932,59 +921,44 @@
stroker->angle_in = angle;
stroker->angle_out = angle + FT_ANGLE_PI;
error = ft_stroker_arcto( stroker, side );
}
- else if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE )
+ else
{
- /* add a square cap */
- FT_Vector delta, delta2;
- FT_Angle rotate = FT_SIDE_TO_ROTATE( side );
+ /* add a square or butt cap */
+ FT_Vector middle, delta;
FT_Fixed radius = stroker->radius;
FT_StrokeBorder border = stroker->borders + side;
- FT_Vector_From_Polar( &delta2, radius, angle + rotate );
- FT_Vector_From_Polar( &delta, radius, angle );
-
- delta.x += stroker->center.x + delta2.x;
- delta.y += stroker->center.y + delta2.y;
+ /* compute middle point and first angle point */
+ FT_Vector_From_Polar( &middle, radius, angle );
+ delta.x = side ? middle.y : -middle.y;
+ delta.y = side ? -middle.x : middle.x;
- error = ft_stroke_border_lineto( border, &delta, FALSE );
- if ( error )
- goto Exit;
-
- FT_Vector_From_Polar( &delta2, radius, angle - rotate );
- FT_Vector_From_Polar( &delta, radius, angle );
-
- delta.x += delta2.x + stroker->center.x;
- delta.y += delta2.y + stroker->center.y;
-
- error = ft_stroke_border_lineto( border, &delta, FALSE );
+ if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE )
+ {
+ middle.x += stroker->center.x;
+ middle.y += stroker->center.y;
}
- else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT )
+ else /* FT_STROKER_LINECAP_BUTT */
{
- /* add a butt ending */
- FT_Vector delta;
- FT_Angle rotate = FT_SIDE_TO_ROTATE( side );
- FT_Fixed radius = stroker->radius;
- FT_StrokeBorder border = stroker->borders + side;
-
-
- FT_Vector_From_Polar( &delta, radius, angle + rotate );
+ middle.x = stroker->center.x;
+ middle.y = stroker->center.y;
+ }
- delta.x += stroker->center.x;
- delta.y += stroker->center.y;
+ delta.x += middle.x;
+ delta.y += middle.y;
error = ft_stroke_border_lineto( border, &delta, FALSE );
if ( error )
goto Exit;
- FT_Vector_From_Polar( &delta, radius, angle - rotate );
-
- delta.x += stroker->center.x;
- delta.y += stroker->center.y;
+ /* compute second angle point */
+ delta.x = middle.x - delta.x + middle.x;
+ delta.y = middle.y - delta.y + middle.y;
error = ft_stroke_border_lineto( border, &delta, FALSE );
}
Exit:
@@ -998,12 +972,12 @@
FT_Int side,
FT_Fixed line_length )
{
FT_StrokeBorder border = stroker->borders + side;
FT_Angle phi, theta, rotate;
- FT_Fixed length, thcos;
- FT_Vector delta;
+ FT_Fixed length;
+ FT_Vector sigma, delta;
FT_Error error = FT_Err_Ok;
FT_Bool intersect; /* use intersection of lines? */
rotate = FT_SIDE_TO_ROTATE( side );
@@ -1017,13 +991,16 @@
theta > 0x59C000 || theta < -0x59C000 )
intersect = FALSE;
else
{
/* compute minimum required length of lines */
- FT_Fixed min_length = ft_pos_abs( FT_MulFix( stroker->radius,
- FT_Tan( theta ) ) );
+ FT_Fixed min_length;
+
+ FT_Vector_Unit( &sigma, theta );
+ min_length =
+ ft_pos_abs( FT_MulDiv( stroker->radius, sigma.y, sigma.x ) );
intersect = FT_BOOL( min_length &&
stroker->line_length >= min_length &&
line_length >= min_length );
}
@@ -1038,17 +1015,15 @@
border->movable = FALSE;
}
else
{
/* compute median angle */
- phi = stroker->angle_in + theta;
-
- thcos = FT_Cos( theta );
+ phi = stroker->angle_in + theta + rotate;
- length = FT_DivFix( stroker->radius, thcos );
+ length = FT_DivFix( stroker->radius, sigma.x );
- FT_Vector_From_Polar( &delta, length, phi + rotate );
+ FT_Vector_From_Polar( &delta, length, phi );
delta.x += stroker->center.x;
delta.y += stroker->center.y;
}
error = ft_stroke_border_lineto( border, &delta, FALSE );
@@ -1071,13 +1046,13 @@
if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND )
error = ft_stroker_arcto( stroker, side );
else
{
/* this is a mitered (pointed) or beveled (truncated) corner */
- FT_Fixed sigma = 0, radius = stroker->radius;
+ FT_Fixed radius = stroker->radius;
+ FT_Vector sigma;
FT_Angle theta = 0, phi = 0;
- FT_Fixed thcos = 0;
FT_Bool bevel, fixed_bevel;
rotate = FT_SIDE_TO_ROTATE( side );
@@ -1085,30 +1060,24 @@
FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL );
fixed_bevel =
FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE );
+ /* check miter limit first */
if ( !bevel )
{
- theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out );
+ theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2;
+
+ if ( theta == FT_ANGLE_PI2 )
+ theta = -rotate;
- if ( theta == FT_ANGLE_PI )
- {
- theta = rotate;
- phi = stroker->angle_in;
- }
- else
- {
- theta /= 2;
phi = stroker->angle_in + theta + rotate;
- }
- thcos = FT_Cos( theta );
- sigma = FT_MulFix( stroker->miter_limit, thcos );
+ FT_Vector_From_Polar( &sigma, stroker->miter_limit, theta );
/* is miter limit exceeded? */
- if ( sigma < 0x10000L )
+ if ( sigma.x < 0x10000L )
{
/* don't create variable bevels for very small deviations; */
/* FT_Sin(x) = 0 for x <= 57 */
if ( fixed_bevel || ft_pos_abs( theta ) > 57 )
bevel = TRUE;
@@ -1131,40 +1100,38 @@
delta.y += stroker->center.y;
border->movable = FALSE;
error = ft_stroke_border_lineto( border, &delta, FALSE );
}
- else /* variable bevel */
+ else /* variable bevel or clipped miter */
{
/* the miter is truncated */
FT_Vector middle, delta;
- FT_Fixed length;
+ FT_Fixed coef;
- /* compute middle point */
+ /* compute middle point and first angle point */
FT_Vector_From_Polar( &middle,
FT_MulFix( radius, stroker->miter_limit ),
phi );
- middle.x += stroker->center.x;
- middle.y += stroker->center.y;
- /* compute first angle point */
- length = FT_MulDiv( radius, 0x10000L - sigma,
- ft_pos_abs( FT_Sin( theta ) ) );
+ coef = FT_DivFix( 0x10000L - sigma.x, sigma.y );
+ delta.x = FT_MulFix( middle.y, coef );
+ delta.y = FT_MulFix( -middle.x, coef );
- FT_Vector_From_Polar( &delta, length, phi + rotate );
+ middle.x += stroker->center.x;
+ middle.y += stroker->center.y;
delta.x += middle.x;
delta.y += middle.y;
error = ft_stroke_border_lineto( border, &delta, FALSE );
if ( error )
goto Exit;
/* compute second angle point */
- FT_Vector_From_Polar( &delta, length, phi - rotate );
- delta.x += middle.x;
- delta.y += middle.y;
+ delta.x = middle.x - delta.x + middle.x;
+ delta.y = middle.y - delta.y + middle.y;
error = ft_stroke_border_lineto( border, &delta, FALSE );
if ( error )
goto Exit;
@@ -1187,11 +1154,11 @@
{
FT_Fixed length;
FT_Vector delta;
- length = FT_DivFix( stroker->radius, thcos );
+ length = FT_MulDiv( stroker->radius, stroker->miter_limit, sigma.x );
FT_Vector_From_Polar( &delta, length, phi );
delta.x += stroker->center.x;
delta.y += stroker->center.y;
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