forked from KolibriOS/kolibrios
754f9336f0
git-svn-id: svn://kolibrios.org@4349 a494cfbc-eb01-0410-851d-a64ba20cac60
1123 lines
30 KiB
C
1123 lines
30 KiB
C
/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
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/* cairo - a vector graphics library with display and print output
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*
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* Copyright © 2002 University of Southern California
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* Copyright © 2013 Intel Corporation
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*
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* This library is free software; you can redistribute it and/or
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* modify it either under the terms of the GNU Lesser General Public
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* License version 2.1 as published by the Free Software Foundation
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* (the "LGPL") or, at your option, under the terms of the Mozilla
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* Public License Version 1.1 (the "MPL"). If you do not alter this
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* notice, a recipient may use your version of this file under either
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* the MPL or the LGPL.
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*
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* You should have received a copy of the LGPL along with this library
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* in the file COPYING-LGPL-2.1; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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* You should have received a copy of the MPL along with this library
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* in the file COPYING-MPL-1.1
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*
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* The contents of this file are subject to the Mozilla Public License
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* Version 1.1 (the "License"); you may not use this file except in
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* compliance with the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
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* OF ANY KIND, either express or implied. See the LGPL or the MPL for
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* the specific language governing rights and limitations.
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*
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* The Original Code is the cairo graphics library.
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*
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* The Initial Developer of the Original Code is University of Southern
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* California.
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*
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* Contributor(s):
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* Carl D. Worth <cworth@cworth.org>
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* Chris Wilson <chris@chris-wilson.co.uk>
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*/
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#include "cairoint.h"
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#include "cairo-box-inline.h"
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#include "cairo-path-fixed-private.h"
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#include "cairo-slope-private.h"
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#include "cairo-stroke-dash-private.h"
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#include "cairo-traps-private.h"
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#include <float.h>
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struct stroker {
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const cairo_stroke_style_t *style;
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const cairo_matrix_t *ctm;
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const cairo_matrix_t *ctm_inverse;
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double spline_cusp_tolerance;
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double half_line_width;
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double tolerance;
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double ctm_determinant;
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cairo_bool_t ctm_det_positive;
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cairo_line_join_t line_join;
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cairo_traps_t *traps;
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cairo_pen_t pen;
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cairo_point_t first_point;
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cairo_bool_t has_initial_sub_path;
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cairo_bool_t has_current_face;
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cairo_stroke_face_t current_face;
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cairo_bool_t has_first_face;
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cairo_stroke_face_t first_face;
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cairo_stroker_dash_t dash;
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cairo_bool_t has_bounds;
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cairo_box_t tight_bounds;
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cairo_box_t line_bounds;
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cairo_box_t join_bounds;
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};
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static cairo_status_t
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stroker_init (struct stroker *stroker,
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const cairo_path_fixed_t *path,
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const cairo_stroke_style_t *style,
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const cairo_matrix_t *ctm,
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const cairo_matrix_t *ctm_inverse,
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double tolerance,
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cairo_traps_t *traps)
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{
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cairo_status_t status;
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stroker->style = style;
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stroker->ctm = ctm;
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stroker->ctm_inverse = NULL;
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if (! _cairo_matrix_is_identity (ctm_inverse))
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stroker->ctm_inverse = ctm_inverse;
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stroker->line_join = style->line_join;
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stroker->half_line_width = style->line_width / 2.0;
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stroker->tolerance = tolerance;
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stroker->traps = traps;
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/* To test whether we need to join two segments of a spline using
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* a round-join or a bevel-join, we can inspect the angle between the
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* two segments. If the difference between the chord distance
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* (half-line-width times the cosine of the bisection angle) and the
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* half-line-width itself is greater than tolerance then we need to
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* inject a point.
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*/
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stroker->spline_cusp_tolerance = 1 - tolerance / stroker->half_line_width;
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stroker->spline_cusp_tolerance *= stroker->spline_cusp_tolerance;
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stroker->spline_cusp_tolerance *= 2;
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stroker->spline_cusp_tolerance -= 1;
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stroker->ctm_determinant = _cairo_matrix_compute_determinant (stroker->ctm);
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stroker->ctm_det_positive = stroker->ctm_determinant >= 0.0;
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status = _cairo_pen_init (&stroker->pen,
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stroker->half_line_width,
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tolerance, ctm);
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if (unlikely (status))
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return status;
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stroker->has_current_face = FALSE;
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stroker->has_first_face = FALSE;
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stroker->has_initial_sub_path = FALSE;
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_cairo_stroker_dash_init (&stroker->dash, style);
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stroker->has_bounds = traps->num_limits;
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if (stroker->has_bounds) {
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/* Extend the bounds in each direction to account for the maximum area
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* we might generate trapezoids, to capture line segments that are outside
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* of the bounds but which might generate rendering that's within bounds.
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*/
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double dx, dy;
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cairo_fixed_t fdx, fdy;
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stroker->tight_bounds = traps->bounds;
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_cairo_stroke_style_max_distance_from_path (stroker->style, path,
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stroker->ctm, &dx, &dy);
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_cairo_stroke_style_max_line_distance_from_path (stroker->style, path,
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stroker->ctm, &dx, &dy);
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fdx = _cairo_fixed_from_double (dx);
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fdy = _cairo_fixed_from_double (dy);
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stroker->line_bounds = stroker->tight_bounds;
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stroker->line_bounds.p1.x -= fdx;
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stroker->line_bounds.p2.x += fdx;
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stroker->line_bounds.p1.y -= fdy;
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stroker->line_bounds.p2.y += fdy;
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_cairo_stroke_style_max_join_distance_from_path (stroker->style, path,
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stroker->ctm, &dx, &dy);
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fdx = _cairo_fixed_from_double (dx);
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fdy = _cairo_fixed_from_double (dy);
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stroker->join_bounds = stroker->tight_bounds;
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stroker->join_bounds.p1.x -= fdx;
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stroker->join_bounds.p2.x += fdx;
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stroker->join_bounds.p1.y -= fdy;
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stroker->join_bounds.p2.y += fdy;
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}
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return CAIRO_STATUS_SUCCESS;
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}
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static void
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stroker_fini (struct stroker *stroker)
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{
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_cairo_pen_fini (&stroker->pen);
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}
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static void
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translate_point (cairo_point_t *point, cairo_point_t *offset)
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{
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point->x += offset->x;
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point->y += offset->y;
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}
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static int
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join_is_clockwise (const cairo_stroke_face_t *in,
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const cairo_stroke_face_t *out)
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{
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return _cairo_slope_compare (&in->dev_vector, &out->dev_vector) < 0;
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}
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static int
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slope_compare_sgn (double dx1, double dy1, double dx2, double dy2)
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{
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double c = dx1 * dy2 - dx2 * dy1;
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if (c > 0) return 1;
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if (c < 0) return -1;
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return 0;
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}
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static cairo_bool_t
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stroker_intersects_join (const struct stroker *stroker,
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const cairo_point_t *in,
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const cairo_point_t *out)
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{
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cairo_line_t segment;
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if (! stroker->has_bounds)
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return TRUE;
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segment.p1 = *in;
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segment.p2 = *out;
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return _cairo_box_intersects_line_segment (&stroker->join_bounds, &segment);
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}
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static void
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join (struct stroker *stroker,
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cairo_stroke_face_t *in,
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cairo_stroke_face_t *out)
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{
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int clockwise = join_is_clockwise (out, in);
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cairo_point_t *inpt, *outpt;
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if (in->cw.x == out->cw.x &&
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in->cw.y == out->cw.y &&
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in->ccw.x == out->ccw.x &&
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in->ccw.y == out->ccw.y)
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{
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return;
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}
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if (clockwise) {
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inpt = &in->ccw;
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outpt = &out->ccw;
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} else {
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inpt = &in->cw;
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outpt = &out->cw;
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}
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if (! stroker_intersects_join (stroker, inpt, outpt))
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return;
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switch (stroker->line_join) {
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case CAIRO_LINE_JOIN_ROUND:
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/* construct a fan around the common midpoint */
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if ((in->dev_slope.x * out->dev_slope.x +
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in->dev_slope.y * out->dev_slope.y) < stroker->spline_cusp_tolerance)
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{
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int start, stop;
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cairo_point_t tri[3];
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cairo_pen_t *pen = &stroker->pen;
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tri[0] = in->point;
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tri[1] = *inpt;
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if (clockwise) {
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_cairo_pen_find_active_ccw_vertices (pen,
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&in->dev_vector, &out->dev_vector,
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&start, &stop);
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while (start != stop) {
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tri[2] = in->point;
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translate_point (&tri[2], &pen->vertices[start].point);
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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tri[1] = tri[2];
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if (start-- == 0)
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start += pen->num_vertices;
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}
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} else {
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_cairo_pen_find_active_cw_vertices (pen,
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&in->dev_vector, &out->dev_vector,
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&start, &stop);
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while (start != stop) {
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tri[2] = in->point;
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translate_point (&tri[2], &pen->vertices[start].point);
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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tri[1] = tri[2];
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if (++start == pen->num_vertices)
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start = 0;
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}
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}
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tri[2] = *outpt;
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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break;
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}
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case CAIRO_LINE_JOIN_MITER:
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default: {
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/* dot product of incoming slope vector with outgoing slope vector */
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double in_dot_out = (-in->usr_vector.x * out->usr_vector.x +
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-in->usr_vector.y * out->usr_vector.y);
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double ml = stroker->style->miter_limit;
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/* Check the miter limit -- lines meeting at an acute angle
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* can generate long miters, the limit converts them to bevel
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*
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* Consider the miter join formed when two line segments
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* meet at an angle psi:
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*
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* /.\
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* /. .\
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* /./ \.\
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* /./psi\.\
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*
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* We can zoom in on the right half of that to see:
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*
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* |\
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* | \ psi/2
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* | \
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* | \
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* | \
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* | \
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* miter \
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* length \
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* | \
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* | .\
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* | . \
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* |. line \
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* \ width \
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* \ \
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*
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*
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* The right triangle in that figure, (the line-width side is
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* shown faintly with three '.' characters), gives us the
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* following expression relating miter length, angle and line
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* width:
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*
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* 1 /sin (psi/2) = miter_length / line_width
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*
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* The right-hand side of this relationship is the same ratio
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* in which the miter limit (ml) is expressed. We want to know
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* when the miter length is within the miter limit. That is
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* when the following condition holds:
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*
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* 1/sin(psi/2) <= ml
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* 1 <= ml sin(psi/2)
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* 1 <= ml² sin²(psi/2)
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* 2 <= ml² 2 sin²(psi/2)
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* 2·sin²(psi/2) = 1-cos(psi)
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* 2 <= ml² (1-cos(psi))
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*
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* in · out = |in| |out| cos (psi)
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*
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* in and out are both unit vectors, so:
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*
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* in · out = cos (psi)
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*
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* 2 <= ml² (1 - in · out)
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*
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*/
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if (2 <= ml * ml * (1 - in_dot_out)) {
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double x1, y1, x2, y2;
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double mx, my;
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double dx1, dx2, dy1, dy2;
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cairo_point_t outer;
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cairo_point_t quad[4];
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double ix, iy;
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double fdx1, fdy1, fdx2, fdy2;
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double mdx, mdy;
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/*
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* we've got the points already transformed to device
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* space, but need to do some computation with them and
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* also need to transform the slope from user space to
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* device space
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*/
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/* outer point of incoming line face */
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x1 = _cairo_fixed_to_double (inpt->x);
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y1 = _cairo_fixed_to_double (inpt->y);
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dx1 = in->usr_vector.x;
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dy1 = in->usr_vector.y;
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cairo_matrix_transform_distance (stroker->ctm, &dx1, &dy1);
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/* outer point of outgoing line face */
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x2 = _cairo_fixed_to_double (outpt->x);
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y2 = _cairo_fixed_to_double (outpt->y);
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dx2 = out->usr_vector.x;
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dy2 = out->usr_vector.y;
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cairo_matrix_transform_distance (stroker->ctm, &dx2, &dy2);
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/*
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* Compute the location of the outer corner of the miter.
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* That's pretty easy -- just the intersection of the two
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* outer edges. We've got slopes and points on each
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* of those edges. Compute my directly, then compute
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* mx by using the edge with the larger dy; that avoids
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* dividing by values close to zero.
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*/
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my = (((x2 - x1) * dy1 * dy2 - y2 * dx2 * dy1 + y1 * dx1 * dy2) /
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(dx1 * dy2 - dx2 * dy1));
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if (fabs (dy1) >= fabs (dy2))
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mx = (my - y1) * dx1 / dy1 + x1;
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else
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mx = (my - y2) * dx2 / dy2 + x2;
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/*
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* When the two outer edges are nearly parallel, slight
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* perturbations in the position of the outer points of the lines
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* caused by representing them in fixed point form can cause the
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* intersection point of the miter to move a large amount. If
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* that moves the miter intersection from between the two faces,
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* then draw a bevel instead.
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*/
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ix = _cairo_fixed_to_double (in->point.x);
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iy = _cairo_fixed_to_double (in->point.y);
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/* slope of one face */
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fdx1 = x1 - ix; fdy1 = y1 - iy;
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/* slope of the other face */
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fdx2 = x2 - ix; fdy2 = y2 - iy;
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/* slope from the intersection to the miter point */
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mdx = mx - ix; mdy = my - iy;
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/*
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* Make sure the miter point line lies between the two
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* faces by comparing the slopes
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*/
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if (slope_compare_sgn (fdx1, fdy1, mdx, mdy) !=
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slope_compare_sgn (fdx2, fdy2, mdx, mdy))
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{
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/*
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* Draw the quadrilateral
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*/
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outer.x = _cairo_fixed_from_double (mx);
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outer.y = _cairo_fixed_from_double (my);
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quad[0] = in->point;
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quad[1] = *inpt;
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quad[2] = outer;
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quad[3] = *outpt;
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_cairo_traps_tessellate_convex_quad (stroker->traps, quad);
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break;
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}
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}
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/* fall through ... */
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}
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case CAIRO_LINE_JOIN_BEVEL: {
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cairo_point_t tri[3];
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tri[0] = in->point;
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tri[1] = *inpt;
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tri[2] = *outpt;
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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break;
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}
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}
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}
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static void
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add_cap (struct stroker *stroker, cairo_stroke_face_t *f)
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{
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switch (stroker->style->line_cap) {
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case CAIRO_LINE_CAP_ROUND: {
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int start, stop;
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cairo_slope_t in_slope, out_slope;
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cairo_point_t tri[3];
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cairo_pen_t *pen = &stroker->pen;
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in_slope = f->dev_vector;
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out_slope.dx = -in_slope.dx;
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out_slope.dy = -in_slope.dy;
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_cairo_pen_find_active_cw_vertices (pen, &in_slope, &out_slope,
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&start, &stop);
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tri[0] = f->point;
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tri[1] = f->cw;
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while (start != stop) {
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tri[2] = f->point;
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translate_point (&tri[2], &pen->vertices[start].point);
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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tri[1] = tri[2];
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if (++start == pen->num_vertices)
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start = 0;
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}
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tri[2] = f->ccw;
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_cairo_traps_tessellate_triangle (stroker->traps, tri);
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break;
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}
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case CAIRO_LINE_CAP_SQUARE: {
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double dx, dy;
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cairo_slope_t fvector;
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cairo_point_t quad[4];
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|
|
dx = f->usr_vector.x;
|
|
dy = f->usr_vector.y;
|
|
dx *= stroker->half_line_width;
|
|
dy *= stroker->half_line_width;
|
|
cairo_matrix_transform_distance (stroker->ctm, &dx, &dy);
|
|
fvector.dx = _cairo_fixed_from_double (dx);
|
|
fvector.dy = _cairo_fixed_from_double (dy);
|
|
|
|
quad[0] = f->cw;
|
|
quad[1].x = f->cw.x + fvector.dx;
|
|
quad[1].y = f->cw.y + fvector.dy;
|
|
quad[2].x = f->ccw.x + fvector.dx;
|
|
quad[2].y = f->ccw.y + fvector.dy;
|
|
quad[3] = f->ccw;
|
|
|
|
_cairo_traps_tessellate_convex_quad (stroker->traps, quad);
|
|
break;
|
|
}
|
|
|
|
case CAIRO_LINE_CAP_BUTT:
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
add_leading_cap (struct stroker *stroker,
|
|
cairo_stroke_face_t *face)
|
|
{
|
|
cairo_stroke_face_t reversed;
|
|
cairo_point_t t;
|
|
|
|
reversed = *face;
|
|
|
|
/* The initial cap needs an outward facing vector. Reverse everything */
|
|
reversed.usr_vector.x = -reversed.usr_vector.x;
|
|
reversed.usr_vector.y = -reversed.usr_vector.y;
|
|
reversed.dev_vector.dx = -reversed.dev_vector.dx;
|
|
reversed.dev_vector.dy = -reversed.dev_vector.dy;
|
|
t = reversed.cw;
|
|
reversed.cw = reversed.ccw;
|
|
reversed.ccw = t;
|
|
|
|
add_cap (stroker, &reversed);
|
|
}
|
|
|
|
static void
|
|
add_trailing_cap (struct stroker *stroker, cairo_stroke_face_t *face)
|
|
{
|
|
add_cap (stroker, face);
|
|
}
|
|
|
|
static inline double
|
|
normalize_slope (double *dx, double *dy)
|
|
{
|
|
double dx0 = *dx, dy0 = *dy;
|
|
|
|
if (dx0 == 0.0 && dy0 == 0.0)
|
|
return 0;
|
|
|
|
if (dx0 == 0.0) {
|
|
*dx = 0.0;
|
|
if (dy0 > 0.0) {
|
|
*dy = 1.0;
|
|
return dy0;
|
|
} else {
|
|
*dy = -1.0;
|
|
return -dy0;
|
|
}
|
|
} else if (dy0 == 0.0) {
|
|
*dy = 0.0;
|
|
if (dx0 > 0.0) {
|
|
*dx = 1.0;
|
|
return dx0;
|
|
} else {
|
|
*dx = -1.0;
|
|
return -dx0;
|
|
}
|
|
} else {
|
|
double mag = hypot (dx0, dy0);
|
|
*dx = dx0 / mag;
|
|
*dy = dy0 / mag;
|
|
return mag;
|
|
}
|
|
}
|
|
|
|
static void
|
|
compute_face (const cairo_point_t *point,
|
|
const cairo_slope_t *dev_slope,
|
|
struct stroker *stroker,
|
|
cairo_stroke_face_t *face)
|
|
{
|
|
double face_dx, face_dy;
|
|
cairo_point_t offset_ccw, offset_cw;
|
|
double slope_dx, slope_dy;
|
|
|
|
slope_dx = _cairo_fixed_to_double (dev_slope->dx);
|
|
slope_dy = _cairo_fixed_to_double (dev_slope->dy);
|
|
face->length = normalize_slope (&slope_dx, &slope_dy);
|
|
face->dev_slope.x = slope_dx;
|
|
face->dev_slope.y = slope_dy;
|
|
|
|
/*
|
|
* rotate to get a line_width/2 vector along the face, note that
|
|
* the vector must be rotated the right direction in device space,
|
|
* but by 90° in user space. So, the rotation depends on
|
|
* whether the ctm reflects or not, and that can be determined
|
|
* by looking at the determinant of the matrix.
|
|
*/
|
|
if (stroker->ctm_inverse) {
|
|
cairo_matrix_transform_distance (stroker->ctm_inverse, &slope_dx, &slope_dy);
|
|
normalize_slope (&slope_dx, &slope_dy);
|
|
|
|
if (stroker->ctm_det_positive) {
|
|
face_dx = - slope_dy * stroker->half_line_width;
|
|
face_dy = slope_dx * stroker->half_line_width;
|
|
} else {
|
|
face_dx = slope_dy * stroker->half_line_width;
|
|
face_dy = - slope_dx * stroker->half_line_width;
|
|
}
|
|
|
|
/* back to device space */
|
|
cairo_matrix_transform_distance (stroker->ctm, &face_dx, &face_dy);
|
|
} else {
|
|
face_dx = - slope_dy * stroker->half_line_width;
|
|
face_dy = slope_dx * stroker->half_line_width;
|
|
}
|
|
|
|
offset_ccw.x = _cairo_fixed_from_double (face_dx);
|
|
offset_ccw.y = _cairo_fixed_from_double (face_dy);
|
|
offset_cw.x = -offset_ccw.x;
|
|
offset_cw.y = -offset_ccw.y;
|
|
|
|
face->ccw = *point;
|
|
translate_point (&face->ccw, &offset_ccw);
|
|
|
|
face->point = *point;
|
|
|
|
face->cw = *point;
|
|
translate_point (&face->cw, &offset_cw);
|
|
|
|
face->usr_vector.x = slope_dx;
|
|
face->usr_vector.y = slope_dy;
|
|
|
|
face->dev_vector = *dev_slope;
|
|
}
|
|
|
|
static void
|
|
add_caps (struct stroker *stroker)
|
|
{
|
|
/* check for a degenerative sub_path */
|
|
if (stroker->has_initial_sub_path &&
|
|
!stroker->has_first_face &&
|
|
!stroker->has_current_face &&
|
|
stroker->style->line_cap == CAIRO_LINE_CAP_ROUND)
|
|
{
|
|
/* pick an arbitrary slope to use */
|
|
cairo_slope_t slope = { CAIRO_FIXED_ONE, 0 };
|
|
cairo_stroke_face_t face;
|
|
|
|
/* arbitrarily choose first_point
|
|
* first_point and current_point should be the same */
|
|
compute_face (&stroker->first_point, &slope, stroker, &face);
|
|
|
|
add_leading_cap (stroker, &face);
|
|
add_trailing_cap (stroker, &face);
|
|
}
|
|
|
|
if (stroker->has_first_face)
|
|
add_leading_cap (stroker, &stroker->first_face);
|
|
|
|
if (stroker->has_current_face)
|
|
add_trailing_cap (stroker, &stroker->current_face);
|
|
}
|
|
|
|
static cairo_bool_t
|
|
stroker_intersects_edge (const struct stroker *stroker,
|
|
const cairo_stroke_face_t *start,
|
|
const cairo_stroke_face_t *end)
|
|
{
|
|
cairo_box_t box;
|
|
|
|
if (! stroker->has_bounds)
|
|
return TRUE;
|
|
|
|
if (_cairo_box_contains_point (&stroker->tight_bounds, &start->cw))
|
|
return TRUE;
|
|
box.p2 = box.p1 = start->cw;
|
|
|
|
if (_cairo_box_contains_point (&stroker->tight_bounds, &start->ccw))
|
|
return TRUE;
|
|
_cairo_box_add_point (&box, &start->ccw);
|
|
|
|
if (_cairo_box_contains_point (&stroker->tight_bounds, &end->cw))
|
|
return TRUE;
|
|
_cairo_box_add_point (&box, &end->cw);
|
|
|
|
if (_cairo_box_contains_point (&stroker->tight_bounds, &end->ccw))
|
|
return TRUE;
|
|
_cairo_box_add_point (&box, &end->ccw);
|
|
|
|
return (box.p2.x > stroker->tight_bounds.p1.x &&
|
|
box.p1.x < stroker->tight_bounds.p2.x &&
|
|
box.p2.y > stroker->tight_bounds.p1.y &&
|
|
box.p1.y < stroker->tight_bounds.p2.y);
|
|
}
|
|
|
|
static void
|
|
add_sub_edge (struct stroker *stroker,
|
|
const cairo_point_t *p1, const cairo_point_t *p2,
|
|
const cairo_slope_t *dev_slope,
|
|
cairo_stroke_face_t *start, cairo_stroke_face_t *end)
|
|
{
|
|
cairo_point_t rectangle[4];
|
|
|
|
compute_face (p1, dev_slope, stroker, start);
|
|
|
|
*end = *start;
|
|
end->point = *p2;
|
|
rectangle[0].x = p2->x - p1->x;
|
|
rectangle[0].y = p2->y - p1->y;
|
|
translate_point (&end->ccw, &rectangle[0]);
|
|
translate_point (&end->cw, &rectangle[0]);
|
|
|
|
if (p1->x == p2->x && p1->y == p2->y)
|
|
return;
|
|
|
|
if (! stroker_intersects_edge (stroker, start, end))
|
|
return;
|
|
|
|
rectangle[0] = start->cw;
|
|
rectangle[1] = start->ccw;
|
|
rectangle[2] = end->ccw;
|
|
rectangle[3] = end->cw;
|
|
|
|
_cairo_traps_tessellate_convex_quad (stroker->traps, rectangle);
|
|
}
|
|
|
|
static cairo_status_t
|
|
move_to (void *closure, const cairo_point_t *point)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
|
|
/* Cap the start and end of the previous sub path as needed */
|
|
add_caps (stroker);
|
|
|
|
stroker->first_point = *point;
|
|
stroker->current_face.point = *point;
|
|
|
|
stroker->has_first_face = FALSE;
|
|
stroker->has_current_face = FALSE;
|
|
stroker->has_initial_sub_path = FALSE;
|
|
|
|
return CAIRO_STATUS_SUCCESS;
|
|
}
|
|
|
|
static cairo_status_t
|
|
move_to_dashed (void *closure, const cairo_point_t *point)
|
|
{
|
|
/* reset the dash pattern for new sub paths */
|
|
struct stroker *stroker = closure;
|
|
|
|
_cairo_stroker_dash_start (&stroker->dash);
|
|
return move_to (closure, point);
|
|
}
|
|
|
|
static cairo_status_t
|
|
line_to (void *closure, const cairo_point_t *point)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_stroke_face_t start, end;
|
|
const cairo_point_t *p1 = &stroker->current_face.point;
|
|
const cairo_point_t *p2 = point;
|
|
cairo_slope_t dev_slope;
|
|
|
|
stroker->has_initial_sub_path = TRUE;
|
|
|
|
if (p1->x == p2->x && p1->y == p2->y)
|
|
return CAIRO_STATUS_SUCCESS;
|
|
|
|
_cairo_slope_init (&dev_slope, p1, p2);
|
|
add_sub_edge (stroker, p1, p2, &dev_slope, &start, &end);
|
|
|
|
if (stroker->has_current_face) {
|
|
/* Join with final face from previous segment */
|
|
join (stroker, &stroker->current_face, &start);
|
|
} else if (!stroker->has_first_face) {
|
|
/* Save sub path's first face in case needed for closing join */
|
|
stroker->first_face = start;
|
|
stroker->has_first_face = TRUE;
|
|
}
|
|
stroker->current_face = end;
|
|
stroker->has_current_face = TRUE;
|
|
|
|
return CAIRO_STATUS_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* Dashed lines. Cap each dash end, join around turns when on
|
|
*/
|
|
static cairo_status_t
|
|
line_to_dashed (void *closure, const cairo_point_t *point)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
double mag, remain, step_length = 0;
|
|
double slope_dx, slope_dy;
|
|
double dx2, dy2;
|
|
cairo_stroke_face_t sub_start, sub_end;
|
|
const cairo_point_t *p1 = &stroker->current_face.point;
|
|
const cairo_point_t *p2 = point;
|
|
cairo_slope_t dev_slope;
|
|
cairo_line_t segment;
|
|
cairo_bool_t fully_in_bounds;
|
|
|
|
stroker->has_initial_sub_path = stroker->dash.dash_starts_on;
|
|
|
|
if (p1->x == p2->x && p1->y == p2->y)
|
|
return CAIRO_STATUS_SUCCESS;
|
|
|
|
fully_in_bounds = TRUE;
|
|
if (stroker->has_bounds &&
|
|
(! _cairo_box_contains_point (&stroker->join_bounds, p1) ||
|
|
! _cairo_box_contains_point (&stroker->join_bounds, p2)))
|
|
{
|
|
fully_in_bounds = FALSE;
|
|
}
|
|
|
|
_cairo_slope_init (&dev_slope, p1, p2);
|
|
|
|
slope_dx = _cairo_fixed_to_double (p2->x - p1->x);
|
|
slope_dy = _cairo_fixed_to_double (p2->y - p1->y);
|
|
|
|
if (stroker->ctm_inverse)
|
|
cairo_matrix_transform_distance (stroker->ctm_inverse, &slope_dx, &slope_dy);
|
|
mag = normalize_slope (&slope_dx, &slope_dy);
|
|
if (mag <= DBL_EPSILON)
|
|
return CAIRO_STATUS_SUCCESS;
|
|
|
|
remain = mag;
|
|
segment.p1 = *p1;
|
|
while (remain) {
|
|
step_length = MIN (stroker->dash.dash_remain, remain);
|
|
remain -= step_length;
|
|
dx2 = slope_dx * (mag - remain);
|
|
dy2 = slope_dy * (mag - remain);
|
|
cairo_matrix_transform_distance (stroker->ctm, &dx2, &dy2);
|
|
segment.p2.x = _cairo_fixed_from_double (dx2) + p1->x;
|
|
segment.p2.y = _cairo_fixed_from_double (dy2) + p1->y;
|
|
|
|
if (stroker->dash.dash_on &&
|
|
(fully_in_bounds ||
|
|
(! stroker->has_first_face && stroker->dash.dash_starts_on) ||
|
|
_cairo_box_intersects_line_segment (&stroker->join_bounds, &segment)))
|
|
{
|
|
add_sub_edge (stroker,
|
|
&segment.p1, &segment.p2,
|
|
&dev_slope,
|
|
&sub_start, &sub_end);
|
|
|
|
if (stroker->has_current_face) {
|
|
/* Join with final face from previous segment */
|
|
join (stroker, &stroker->current_face, &sub_start);
|
|
|
|
stroker->has_current_face = FALSE;
|
|
} else if (! stroker->has_first_face && stroker->dash.dash_starts_on) {
|
|
/* Save sub path's first face in case needed for closing join */
|
|
stroker->first_face = sub_start;
|
|
stroker->has_first_face = TRUE;
|
|
} else {
|
|
/* Cap dash start if not connecting to a previous segment */
|
|
add_leading_cap (stroker, &sub_start);
|
|
}
|
|
|
|
if (remain) {
|
|
/* Cap dash end if not at end of segment */
|
|
add_trailing_cap (stroker, &sub_end);
|
|
} else {
|
|
stroker->current_face = sub_end;
|
|
stroker->has_current_face = TRUE;
|
|
}
|
|
} else {
|
|
if (stroker->has_current_face) {
|
|
/* Cap final face from previous segment */
|
|
add_trailing_cap (stroker, &stroker->current_face);
|
|
|
|
stroker->has_current_face = FALSE;
|
|
}
|
|
}
|
|
|
|
_cairo_stroker_dash_step (&stroker->dash, step_length);
|
|
segment.p1 = segment.p2;
|
|
}
|
|
|
|
if (stroker->dash.dash_on && ! stroker->has_current_face) {
|
|
/* This segment ends on a transition to dash_on, compute a new face
|
|
* and add cap for the beginning of the next dash_on step.
|
|
*
|
|
* Note: this will create a degenerate cap if this is not the last line
|
|
* in the path. Whether this behaviour is desirable or not is debatable.
|
|
* On one side these degenerate caps can not be reproduced with regular
|
|
* path stroking.
|
|
* On the other hand, Acroread 7 also produces the degenerate caps.
|
|
*/
|
|
compute_face (point, &dev_slope, stroker, &stroker->current_face);
|
|
|
|
add_leading_cap (stroker, &stroker->current_face);
|
|
|
|
stroker->has_current_face = TRUE;
|
|
} else
|
|
stroker->current_face.point = *point;
|
|
|
|
return CAIRO_STATUS_SUCCESS;
|
|
}
|
|
|
|
static cairo_status_t
|
|
spline_to (void *closure,
|
|
const cairo_point_t *point,
|
|
const cairo_slope_t *tangent)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_stroke_face_t face;
|
|
|
|
if ((tangent->dx | tangent->dy) == 0) {
|
|
cairo_point_t t;
|
|
|
|
face = stroker->current_face;
|
|
|
|
face.usr_vector.x = -face.usr_vector.x;
|
|
face.usr_vector.y = -face.usr_vector.y;
|
|
face.dev_slope.x = -face.dev_slope.x;
|
|
face.dev_slope.y = -face.dev_slope.y;
|
|
face.dev_vector.dx = -face.dev_vector.dx;
|
|
face.dev_vector.dy = -face.dev_vector.dy;
|
|
|
|
t = face.cw;
|
|
face.cw = face.ccw;
|
|
face.ccw = t;
|
|
|
|
join (stroker, &stroker->current_face, &face);
|
|
} else {
|
|
cairo_point_t rectangle[4];
|
|
|
|
compute_face (&stroker->current_face.point, tangent, stroker, &face);
|
|
|
|
join (stroker, &stroker->current_face, &face);
|
|
|
|
rectangle[0] = face.cw;
|
|
rectangle[1] = face.ccw;
|
|
|
|
rectangle[2].x = point->x - face.point.x;
|
|
rectangle[2].y = point->y - face.point.y;
|
|
face.point = *point;
|
|
translate_point (&face.ccw, &rectangle[2]);
|
|
translate_point (&face.cw, &rectangle[2]);
|
|
|
|
rectangle[2] = face.ccw;
|
|
rectangle[3] = face.cw;
|
|
|
|
_cairo_traps_tessellate_convex_quad (stroker->traps, rectangle);
|
|
}
|
|
|
|
stroker->current_face = face;
|
|
|
|
return CAIRO_STATUS_SUCCESS;
|
|
}
|
|
|
|
static cairo_status_t
|
|
curve_to (void *closure,
|
|
const cairo_point_t *b,
|
|
const cairo_point_t *c,
|
|
const cairo_point_t *d)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_line_join_t line_join_save;
|
|
cairo_spline_t spline;
|
|
cairo_stroke_face_t face;
|
|
cairo_status_t status;
|
|
|
|
if (stroker->has_bounds &&
|
|
! _cairo_spline_intersects (&stroker->current_face.point, b, c, d,
|
|
&stroker->line_bounds))
|
|
return line_to (closure, d);
|
|
|
|
if (! _cairo_spline_init (&spline, spline_to, stroker,
|
|
&stroker->current_face.point, b, c, d))
|
|
return line_to (closure, d);
|
|
|
|
compute_face (&stroker->current_face.point, &spline.initial_slope,
|
|
stroker, &face);
|
|
|
|
if (stroker->has_current_face) {
|
|
/* Join with final face from previous segment */
|
|
join (stroker, &stroker->current_face, &face);
|
|
} else {
|
|
if (! stroker->has_first_face) {
|
|
/* Save sub path's first face in case needed for closing join */
|
|
stroker->first_face = face;
|
|
stroker->has_first_face = TRUE;
|
|
}
|
|
stroker->has_current_face = TRUE;
|
|
}
|
|
stroker->current_face = face;
|
|
|
|
/* Temporarily modify the stroker to use round joins to guarantee
|
|
* smooth stroked curves. */
|
|
line_join_save = stroker->line_join;
|
|
stroker->line_join = CAIRO_LINE_JOIN_ROUND;
|
|
|
|
status = _cairo_spline_decompose (&spline, stroker->tolerance);
|
|
|
|
stroker->line_join = line_join_save;
|
|
|
|
return status;
|
|
}
|
|
|
|
static cairo_status_t
|
|
curve_to_dashed (void *closure,
|
|
const cairo_point_t *b,
|
|
const cairo_point_t *c,
|
|
const cairo_point_t *d)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_spline_t spline;
|
|
cairo_line_join_t line_join_save;
|
|
cairo_spline_add_point_func_t func;
|
|
cairo_status_t status;
|
|
|
|
func = (cairo_spline_add_point_func_t)line_to_dashed;
|
|
|
|
if (stroker->has_bounds &&
|
|
! _cairo_spline_intersects (&stroker->current_face.point, b, c, b,
|
|
&stroker->line_bounds))
|
|
return func (closure, d, NULL);
|
|
|
|
if (! _cairo_spline_init (&spline, func, stroker,
|
|
&stroker->current_face.point, b, c, d))
|
|
return func (closure, d, NULL);
|
|
|
|
/* Temporarily modify the stroker to use round joins to guarantee
|
|
* smooth stroked curves. */
|
|
line_join_save = stroker->line_join;
|
|
stroker->line_join = CAIRO_LINE_JOIN_ROUND;
|
|
|
|
status = _cairo_spline_decompose (&spline, stroker->tolerance);
|
|
|
|
stroker->line_join = line_join_save;
|
|
|
|
return status;
|
|
}
|
|
|
|
static cairo_status_t
|
|
_close_path (struct stroker *stroker)
|
|
{
|
|
if (stroker->has_first_face && stroker->has_current_face) {
|
|
/* Join first and final faces of sub path */
|
|
join (stroker, &stroker->current_face, &stroker->first_face);
|
|
} else {
|
|
/* Cap the start and end of the sub path as needed */
|
|
add_caps (stroker);
|
|
}
|
|
|
|
stroker->has_initial_sub_path = FALSE;
|
|
stroker->has_first_face = FALSE;
|
|
stroker->has_current_face = FALSE;
|
|
return CAIRO_STATUS_SUCCESS;
|
|
}
|
|
|
|
static cairo_status_t
|
|
close_path (void *closure)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_status_t status;
|
|
|
|
status = line_to (stroker, &stroker->first_point);
|
|
if (unlikely (status))
|
|
return status;
|
|
|
|
return _close_path (stroker);
|
|
}
|
|
|
|
static cairo_status_t
|
|
close_path_dashed (void *closure)
|
|
{
|
|
struct stroker *stroker = closure;
|
|
cairo_status_t status;
|
|
|
|
status = line_to_dashed (stroker, &stroker->first_point);
|
|
if (unlikely (status))
|
|
return status;
|
|
|
|
return _close_path (stroker);
|
|
}
|
|
|
|
cairo_int_status_t
|
|
_cairo_path_fixed_stroke_to_traps (const cairo_path_fixed_t *path,
|
|
const cairo_stroke_style_t *style,
|
|
const cairo_matrix_t *ctm,
|
|
const cairo_matrix_t *ctm_inverse,
|
|
double tolerance,
|
|
cairo_traps_t *traps)
|
|
{
|
|
struct stroker stroker;
|
|
cairo_status_t status;
|
|
|
|
status = stroker_init (&stroker, path, style,
|
|
ctm, ctm_inverse, tolerance,
|
|
traps);
|
|
if (unlikely (status))
|
|
return status;
|
|
|
|
if (stroker.dash.dashed)
|
|
status = _cairo_path_fixed_interpret (path,
|
|
move_to_dashed,
|
|
line_to_dashed,
|
|
curve_to_dashed,
|
|
close_path_dashed,
|
|
&stroker);
|
|
else
|
|
status = _cairo_path_fixed_interpret (path,
|
|
move_to,
|
|
line_to,
|
|
curve_to,
|
|
close_path,
|
|
&stroker);
|
|
assert(status == CAIRO_STATUS_SUCCESS);
|
|
add_caps (&stroker);
|
|
|
|
stroker_fini (&stroker);
|
|
|
|
return traps->status;
|
|
}
|