diff options
Diffstat (limited to 'Build/source/libs/cairo/cairo-src/src/cairo-path-stroke.c')
-rw-r--r-- | Build/source/libs/cairo/cairo-src/src/cairo-path-stroke.c | 1485 |
1 files changed, 0 insertions, 1485 deletions
diff --git a/Build/source/libs/cairo/cairo-src/src/cairo-path-stroke.c b/Build/source/libs/cairo/cairo-src/src/cairo-path-stroke.c deleted file mode 100644 index 64cec8f272e..00000000000 --- a/Build/source/libs/cairo/cairo-src/src/cairo-path-stroke.c +++ /dev/null @@ -1,1485 +0,0 @@ -/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */ -/* cairo - a vector graphics library with display and print output - * - * Copyright © 2002 University of Southern California - * - * This library is free software; you can redistribute it and/or - * modify it either under the terms of the GNU Lesser General Public - * License version 2.1 as published by the Free Software Foundation - * (the "LGPL") or, at your option, under the terms of the Mozilla - * Public License Version 1.1 (the "MPL"). If you do not alter this - * notice, a recipient may use your version of this file under either - * the MPL or the LGPL. - * - * You should have received a copy of the LGPL along with this library - * in the file COPYING-LGPL-2.1; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA - * You should have received a copy of the MPL along with this library - * in the file COPYING-MPL-1.1 - * - * The contents of this file are subject to the Mozilla Public License - * Version 1.1 (the "License"); you may not use this file except in - * compliance with the License. You may obtain a copy of the License at - * http://www.mozilla.org/MPL/ - * - * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY - * OF ANY KIND, either express or implied. See the LGPL or the MPL for - * the specific language governing rights and limitations. - * - * The Original Code is the cairo graphics library. - * - * The Initial Developer of the Original Code is University of Southern - * California. - * - * Contributor(s): - * Carl D. Worth <cworth@cworth.org> - * Chris Wilson <chris@chris-wilson.co.uk> - */ - -#define _DEFAULT_SOURCE /* for hypot() */ -#include "cairoint.h" - -#include "cairo-box-inline.h" -#include "cairo-boxes-private.h" -#include "cairo-error-private.h" -#include "cairo-path-fixed-private.h" -#include "cairo-slope-private.h" -#include "cairo-stroke-dash-private.h" -#include "cairo-traps-private.h" - -typedef struct cairo_stroker { - cairo_stroke_style_t style; - - const cairo_matrix_t *ctm; - const cairo_matrix_t *ctm_inverse; - double half_line_width; - double tolerance; - double spline_cusp_tolerance; - double ctm_determinant; - cairo_bool_t ctm_det_positive; - - void *closure; - cairo_status_t (*add_external_edge) (void *closure, - const cairo_point_t *p1, - const cairo_point_t *p2); - cairo_status_t (*add_triangle) (void *closure, - const cairo_point_t triangle[3]); - cairo_status_t (*add_triangle_fan) (void *closure, - const cairo_point_t *midpt, - const cairo_point_t *points, - int npoints); - cairo_status_t (*add_convex_quad) (void *closure, - const cairo_point_t quad[4]); - - cairo_pen_t pen; - - cairo_point_t current_point; - cairo_point_t first_point; - - cairo_bool_t has_initial_sub_path; - - cairo_bool_t has_current_face; - cairo_stroke_face_t current_face; - - cairo_bool_t has_first_face; - cairo_stroke_face_t first_face; - - cairo_stroker_dash_t dash; - - cairo_bool_t has_bounds; - cairo_box_t bounds; -} cairo_stroker_t; - -static void -_cairo_stroker_limit (cairo_stroker_t *stroker, - const cairo_path_fixed_t *path, - const cairo_box_t *boxes, - int num_boxes) -{ - double dx, dy; - cairo_fixed_t fdx, fdy; - - stroker->has_bounds = TRUE; - _cairo_boxes_get_extents (boxes, num_boxes, &stroker->bounds); - - /* Extend the bounds in each direction to account for the maximum area - * we might generate trapezoids, to capture line segments that are outside - * of the bounds but which might generate rendering that's within bounds. - */ - - _cairo_stroke_style_max_distance_from_path (&stroker->style, path, - stroker->ctm, &dx, &dy); - - fdx = _cairo_fixed_from_double (dx); - fdy = _cairo_fixed_from_double (dy); - - stroker->bounds.p1.x -= fdx; - stroker->bounds.p2.x += fdx; - - stroker->bounds.p1.y -= fdy; - stroker->bounds.p2.y += fdy; -} - -static cairo_status_t -_cairo_stroker_init (cairo_stroker_t *stroker, - const cairo_path_fixed_t *path, - const cairo_stroke_style_t *stroke_style, - const cairo_matrix_t *ctm, - const cairo_matrix_t *ctm_inverse, - double tolerance, - const cairo_box_t *limits, - int num_limits) -{ - cairo_status_t status; - - stroker->style = *stroke_style; - stroker->ctm = ctm; - stroker->ctm_inverse = ctm_inverse; - stroker->tolerance = tolerance; - stroker->half_line_width = stroke_style->line_width / 2.0; - - /* To test whether we need to join two segments of a spline using - * a round-join or a bevel-join, we can inspect the angle between the - * two segments. If the difference between the chord distance - * (half-line-width times the cosine of the bisection angle) and the - * half-line-width itself is greater than tolerance then we need to - * inject a point. - */ - stroker->spline_cusp_tolerance = 1 - tolerance / stroker->half_line_width; - stroker->spline_cusp_tolerance *= stroker->spline_cusp_tolerance; - stroker->spline_cusp_tolerance *= 2; - stroker->spline_cusp_tolerance -= 1; - - stroker->ctm_determinant = _cairo_matrix_compute_determinant (stroker->ctm); - stroker->ctm_det_positive = stroker->ctm_determinant >= 0.0; - - status = _cairo_pen_init (&stroker->pen, - stroker->half_line_width, tolerance, ctm); - if (unlikely (status)) - return status; - - stroker->has_current_face = FALSE; - stroker->has_first_face = FALSE; - stroker->has_initial_sub_path = FALSE; - - _cairo_stroker_dash_init (&stroker->dash, stroke_style); - - stroker->add_external_edge = NULL; - - stroker->has_bounds = FALSE; - if (num_limits) - _cairo_stroker_limit (stroker, path, limits, num_limits); - - return CAIRO_STATUS_SUCCESS; -} - -static void -_cairo_stroker_fini (cairo_stroker_t *stroker) -{ - _cairo_pen_fini (&stroker->pen); -} - -static void -_translate_point (cairo_point_t *point, const cairo_point_t *offset) -{ - point->x += offset->x; - point->y += offset->y; -} - -static int -_cairo_stroker_join_is_clockwise (const cairo_stroke_face_t *in, - const cairo_stroke_face_t *out) -{ - cairo_slope_t in_slope, out_slope; - - _cairo_slope_init (&in_slope, &in->point, &in->cw); - _cairo_slope_init (&out_slope, &out->point, &out->cw); - - return _cairo_slope_compare (&in_slope, &out_slope) < 0; -} - -/** - * _cairo_slope_compare_sgn: - * - * Return -1, 0 or 1 depending on the relative slopes of - * two lines. - **/ -static int -_cairo_slope_compare_sgn (double dx1, double dy1, double dx2, double dy2) -{ - double c = (dx1 * dy2 - dx2 * dy1); - - if (c > 0) return 1; - if (c < 0) return -1; - return 0; -} - -static inline int -_range_step (int i, int step, int max) -{ - i += step; - if (i < 0) - i = max - 1; - if (i >= max) - i = 0; - return i; -} - -/* - * Construct a fan around the midpoint using the vertices from pen between - * inpt and outpt. - */ -static cairo_status_t -_tessellate_fan (cairo_stroker_t *stroker, - const cairo_slope_t *in_vector, - const cairo_slope_t *out_vector, - const cairo_point_t *midpt, - const cairo_point_t *inpt, - const cairo_point_t *outpt, - cairo_bool_t clockwise) -{ - cairo_point_t stack_points[64], *points = stack_points; - cairo_pen_t *pen = &stroker->pen; - int start, stop, num_points = 0; - cairo_status_t status; - - if (stroker->has_bounds && - ! _cairo_box_contains_point (&stroker->bounds, midpt)) - goto BEVEL; - - assert (stroker->pen.num_vertices); - - if (clockwise) { - _cairo_pen_find_active_ccw_vertices (pen, - in_vector, out_vector, - &start, &stop); - if (stroker->add_external_edge) { - cairo_point_t last; - last = *inpt; - while (start != stop) { - cairo_point_t p = *midpt; - _translate_point (&p, &pen->vertices[start].point); - - status = stroker->add_external_edge (stroker->closure, - &last, &p); - if (unlikely (status)) - return status; - last = p; - - if (start-- == 0) - start += pen->num_vertices; - } - status = stroker->add_external_edge (stroker->closure, - &last, outpt); - } else { - if (start == stop) - goto BEVEL; - - num_points = stop - start; - if (num_points < 0) - num_points += pen->num_vertices; - num_points += 2; - if (num_points > ARRAY_LENGTH(stack_points)) { - points = _cairo_malloc_ab (num_points, sizeof (cairo_point_t)); - if (unlikely (points == NULL)) - return _cairo_error (CAIRO_STATUS_NO_MEMORY); - } - - points[0] = *inpt; - num_points = 1; - while (start != stop) { - points[num_points] = *midpt; - _translate_point (&points[num_points], &pen->vertices[start].point); - num_points++; - - if (start-- == 0) - start += pen->num_vertices; - } - points[num_points++] = *outpt; - } - } else { - _cairo_pen_find_active_cw_vertices (pen, - in_vector, out_vector, - &start, &stop); - if (stroker->add_external_edge) { - cairo_point_t last; - last = *inpt; - while (start != stop) { - cairo_point_t p = *midpt; - _translate_point (&p, &pen->vertices[start].point); - - status = stroker->add_external_edge (stroker->closure, - &p, &last); - if (unlikely (status)) - return status; - last = p; - - if (++start == pen->num_vertices) - start = 0; - } - status = stroker->add_external_edge (stroker->closure, - outpt, &last); - } else { - if (start == stop) - goto BEVEL; - - num_points = stop - start; - if (num_points < 0) - num_points += pen->num_vertices; - num_points += 2; - if (num_points > ARRAY_LENGTH(stack_points)) { - points = _cairo_malloc_ab (num_points, sizeof (cairo_point_t)); - if (unlikely (points == NULL)) - return _cairo_error (CAIRO_STATUS_NO_MEMORY); - } - - points[0] = *inpt; - num_points = 1; - while (start != stop) { - points[num_points] = *midpt; - _translate_point (&points[num_points], &pen->vertices[start].point); - num_points++; - - if (++start == pen->num_vertices) - start = 0; - } - points[num_points++] = *outpt; - } - } - - if (num_points) { - status = stroker->add_triangle_fan (stroker->closure, - midpt, points, num_points); - } - - if (points != stack_points) - free (points); - - return status; - -BEVEL: - /* Ensure a leak free connection... */ - if (stroker->add_external_edge != NULL) { - if (clockwise) - return stroker->add_external_edge (stroker->closure, inpt, outpt); - else - return stroker->add_external_edge (stroker->closure, outpt, inpt); - } else { - stack_points[0] = *midpt; - stack_points[1] = *inpt; - stack_points[2] = *outpt; - return stroker->add_triangle (stroker->closure, stack_points); - } -} - -static cairo_status_t -_cairo_stroker_join (cairo_stroker_t *stroker, - const cairo_stroke_face_t *in, - const cairo_stroke_face_t *out) -{ - int clockwise = _cairo_stroker_join_is_clockwise (out, in); - const cairo_point_t *inpt, *outpt; - cairo_point_t points[4]; - cairo_status_t status; - - if (in->cw.x == out->cw.x && in->cw.y == out->cw.y && - in->ccw.x == out->ccw.x && in->ccw.y == out->ccw.y) - { - return CAIRO_STATUS_SUCCESS; - } - - if (clockwise) { - if (stroker->add_external_edge != NULL) { - status = stroker->add_external_edge (stroker->closure, - &out->cw, &in->point); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &in->point, &in->cw); - if (unlikely (status)) - return status; - } - - inpt = &in->ccw; - outpt = &out->ccw; - } else { - if (stroker->add_external_edge != NULL) { - status = stroker->add_external_edge (stroker->closure, - &in->ccw, &in->point); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &in->point, &out->ccw); - if (unlikely (status)) - return status; - } - - inpt = &in->cw; - outpt = &out->cw; - } - - switch (stroker->style.line_join) { - case CAIRO_LINE_JOIN_ROUND: - /* construct a fan around the common midpoint */ - return _tessellate_fan (stroker, - &in->dev_vector, - &out->dev_vector, - &in->point, inpt, outpt, - clockwise); - - case CAIRO_LINE_JOIN_MITER: - default: { - /* dot product of incoming slope vector with outgoing slope vector */ - double in_dot_out = -in->usr_vector.x * out->usr_vector.x + - -in->usr_vector.y * out->usr_vector.y; - double ml = stroker->style.miter_limit; - - /* Check the miter limit -- lines meeting at an acute angle - * can generate long miters, the limit converts them to bevel - * - * Consider the miter join formed when two line segments - * meet at an angle psi: - * - * /.\ - * /. .\ - * /./ \.\ - * /./psi\.\ - * - * We can zoom in on the right half of that to see: - * - * |\ - * | \ psi/2 - * | \ - * | \ - * | \ - * | \ - * miter \ - * length \ - * | \ - * | .\ - * | . \ - * |. line \ - * \ width \ - * \ \ - * - * - * The right triangle in that figure, (the line-width side is - * shown faintly with three '.' characters), gives us the - * following expression relating miter length, angle and line - * width: - * - * 1 /sin (psi/2) = miter_length / line_width - * - * The right-hand side of this relationship is the same ratio - * in which the miter limit (ml) is expressed. We want to know - * when the miter length is within the miter limit. That is - * when the following condition holds: - * - * 1/sin(psi/2) <= ml - * 1 <= ml sin(psi/2) - * 1 <= ml² sin²(psi/2) - * 2 <= ml² 2 sin²(psi/2) - * 2·sin²(psi/2) = 1-cos(psi) - * 2 <= ml² (1-cos(psi)) - * - * in · out = |in| |out| cos (psi) - * - * in and out are both unit vectors, so: - * - * in · out = cos (psi) - * - * 2 <= ml² (1 - in · out) - * - */ - if (2 <= ml * ml * (1 - in_dot_out)) { - double x1, y1, x2, y2; - double mx, my; - double dx1, dx2, dy1, dy2; - double ix, iy; - double fdx1, fdy1, fdx2, fdy2; - double mdx, mdy; - - /* - * we've got the points already transformed to device - * space, but need to do some computation with them and - * also need to transform the slope from user space to - * device space - */ - /* outer point of incoming line face */ - x1 = _cairo_fixed_to_double (inpt->x); - y1 = _cairo_fixed_to_double (inpt->y); - dx1 = in->usr_vector.x; - dy1 = in->usr_vector.y; - cairo_matrix_transform_distance (stroker->ctm, &dx1, &dy1); - - /* outer point of outgoing line face */ - x2 = _cairo_fixed_to_double (outpt->x); - y2 = _cairo_fixed_to_double (outpt->y); - dx2 = out->usr_vector.x; - dy2 = out->usr_vector.y; - cairo_matrix_transform_distance (stroker->ctm, &dx2, &dy2); - - /* - * Compute the location of the outer corner of the miter. - * That's pretty easy -- just the intersection of the two - * outer edges. We've got slopes and points on each - * of those edges. Compute my directly, then compute - * mx by using the edge with the larger dy; that avoids - * dividing by values close to zero. - */ - my = (((x2 - x1) * dy1 * dy2 - y2 * dx2 * dy1 + y1 * dx1 * dy2) / - (dx1 * dy2 - dx2 * dy1)); - if (fabs (dy1) >= fabs (dy2)) - mx = (my - y1) * dx1 / dy1 + x1; - else - mx = (my - y2) * dx2 / dy2 + x2; - - /* - * When the two outer edges are nearly parallel, slight - * perturbations in the position of the outer points of the lines - * caused by representing them in fixed point form can cause the - * intersection point of the miter to move a large amount. If - * that moves the miter intersection from between the two faces, - * then draw a bevel instead. - */ - - ix = _cairo_fixed_to_double (in->point.x); - iy = _cairo_fixed_to_double (in->point.y); - - /* slope of one face */ - fdx1 = x1 - ix; fdy1 = y1 - iy; - - /* slope of the other face */ - fdx2 = x2 - ix; fdy2 = y2 - iy; - - /* slope from the intersection to the miter point */ - mdx = mx - ix; mdy = my - iy; - - /* - * Make sure the miter point line lies between the two - * faces by comparing the slopes - */ - if (_cairo_slope_compare_sgn (fdx1, fdy1, mdx, mdy) != - _cairo_slope_compare_sgn (fdx2, fdy2, mdx, mdy)) - { - if (stroker->add_external_edge != NULL) { - points[0].x = _cairo_fixed_from_double (mx); - points[0].y = _cairo_fixed_from_double (my); - - if (clockwise) { - status = stroker->add_external_edge (stroker->closure, - inpt, &points[0]); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &points[0], outpt); - if (unlikely (status)) - return status; - } else { - status = stroker->add_external_edge (stroker->closure, - outpt, &points[0]); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &points[0], inpt); - if (unlikely (status)) - return status; - } - - return CAIRO_STATUS_SUCCESS; - } else { - points[0] = in->point; - points[1] = *inpt; - points[2].x = _cairo_fixed_from_double (mx); - points[2].y = _cairo_fixed_from_double (my); - points[3] = *outpt; - - return stroker->add_convex_quad (stroker->closure, points); - } - } - } - } - - /* fall through ... */ - - case CAIRO_LINE_JOIN_BEVEL: - if (stroker->add_external_edge != NULL) { - if (clockwise) { - return stroker->add_external_edge (stroker->closure, - inpt, outpt); - } else { - return stroker->add_external_edge (stroker->closure, - outpt, inpt); - } - } else { - points[0] = in->point; - points[1] = *inpt; - points[2] = *outpt; - - return stroker->add_triangle (stroker->closure, points); - } - } -} - -static cairo_status_t -_cairo_stroker_add_cap (cairo_stroker_t *stroker, - const cairo_stroke_face_t *f) -{ - switch (stroker->style.line_cap) { - case CAIRO_LINE_CAP_ROUND: { - cairo_slope_t slope; - - slope.dx = -f->dev_vector.dx; - slope.dy = -f->dev_vector.dy; - - return _tessellate_fan (stroker, - &f->dev_vector, - &slope, - &f->point, &f->cw, &f->ccw, - FALSE); - - } - - case CAIRO_LINE_CAP_SQUARE: { - double dx, dy; - cairo_slope_t fvector; - cairo_point_t quad[4]; - - 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->ccw; - quad[1].x = f->ccw.x + fvector.dx; - quad[1].y = f->ccw.y + fvector.dy; - quad[2].x = f->cw.x + fvector.dx; - quad[2].y = f->cw.y + fvector.dy; - quad[3] = f->cw; - - if (stroker->add_external_edge != NULL) { - cairo_status_t status; - - status = stroker->add_external_edge (stroker->closure, - &quad[0], &quad[1]); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &quad[1], &quad[2]); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &quad[2], &quad[3]); - if (unlikely (status)) - return status; - - return CAIRO_STATUS_SUCCESS; - } else { - return stroker->add_convex_quad (stroker->closure, quad); - } - } - - case CAIRO_LINE_CAP_BUTT: - default: - if (stroker->add_external_edge != NULL) { - return stroker->add_external_edge (stroker->closure, - &f->ccw, &f->cw); - } else { - return CAIRO_STATUS_SUCCESS; - } - } -} - -static cairo_status_t -_cairo_stroker_add_leading_cap (cairo_stroker_t *stroker, - const 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; - - return _cairo_stroker_add_cap (stroker, &reversed); -} - -static cairo_status_t -_cairo_stroker_add_trailing_cap (cairo_stroker_t *stroker, - const cairo_stroke_face_t *face) -{ - return _cairo_stroker_add_cap (stroker, face); -} - -static inline cairo_bool_t -_compute_normalized_device_slope (double *dx, double *dy, - const cairo_matrix_t *ctm_inverse, - double *mag_out) -{ - double dx0 = *dx, dy0 = *dy; - double mag; - - cairo_matrix_transform_distance (ctm_inverse, &dx0, &dy0); - - if (dx0 == 0.0 && dy0 == 0.0) { - if (mag_out) - *mag_out = 0.0; - return FALSE; - } - - if (dx0 == 0.0) { - *dx = 0.0; - if (dy0 > 0.0) { - mag = dy0; - *dy = 1.0; - } else { - mag = -dy0; - *dy = -1.0; - } - } else if (dy0 == 0.0) { - *dy = 0.0; - if (dx0 > 0.0) { - mag = dx0; - *dx = 1.0; - } else { - mag = -dx0; - *dx = -1.0; - } - } else { - mag = hypot (dx0, dy0); - *dx = dx0 / mag; - *dy = dy0 / mag; - } - - if (mag_out) - *mag_out = mag; - - return TRUE; -} - -static void -_compute_face (const cairo_point_t *point, - const cairo_slope_t *dev_slope, - double slope_dx, - double slope_dy, - cairo_stroker_t *stroker, - cairo_stroke_face_t *face) -{ - double face_dx, face_dy; - cairo_point_t offset_ccw, offset_cw; - - /* - * 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_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); - - 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 cairo_status_t -_cairo_stroker_add_caps (cairo_stroker_t *stroker) -{ - cairo_status_t status; - - /* 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 */ - double dx = 1.0, dy = 0.0; - cairo_slope_t slope = { CAIRO_FIXED_ONE, 0 }; - cairo_stroke_face_t face; - - _compute_normalized_device_slope (&dx, &dy, - stroker->ctm_inverse, NULL); - - /* arbitrarily choose first_point - * first_point and current_point should be the same */ - _compute_face (&stroker->first_point, &slope, dx, dy, stroker, &face); - - status = _cairo_stroker_add_leading_cap (stroker, &face); - if (unlikely (status)) - return status; - - status = _cairo_stroker_add_trailing_cap (stroker, &face); - if (unlikely (status)) - return status; - } - - if (stroker->has_first_face) { - status = _cairo_stroker_add_leading_cap (stroker, - &stroker->first_face); - if (unlikely (status)) - return status; - } - - if (stroker->has_current_face) { - status = _cairo_stroker_add_trailing_cap (stroker, - &stroker->current_face); - if (unlikely (status)) - return status; - } - - return CAIRO_STATUS_SUCCESS; -} - -static cairo_status_t -_cairo_stroker_add_sub_edge (cairo_stroker_t *stroker, - const cairo_point_t *p1, - const cairo_point_t *p2, - cairo_slope_t *dev_slope, - double slope_dx, double slope_dy, - cairo_stroke_face_t *start, - cairo_stroke_face_t *end) -{ - _compute_face (p1, dev_slope, slope_dx, slope_dy, stroker, start); - *end = *start; - - if (p1->x == p2->x && p1->y == p2->y) - return CAIRO_STATUS_SUCCESS; - - end->point = *p2; - end->ccw.x += p2->x - p1->x; - end->ccw.y += p2->y - p1->y; - end->cw.x += p2->x - p1->x; - end->cw.y += p2->y - p1->y; - - if (stroker->add_external_edge != NULL) { - cairo_status_t status; - - status = stroker->add_external_edge (stroker->closure, - &end->cw, &start->cw); - if (unlikely (status)) - return status; - - status = stroker->add_external_edge (stroker->closure, - &start->ccw, &end->ccw); - if (unlikely (status)) - return status; - - return CAIRO_STATUS_SUCCESS; - } else { - cairo_point_t quad[4]; - - quad[0] = start->cw; - quad[1] = end->cw; - quad[2] = end->ccw; - quad[3] = start->ccw; - - return stroker->add_convex_quad (stroker->closure, quad); - } -} - -static cairo_status_t -_cairo_stroker_move_to (void *closure, - const cairo_point_t *point) -{ - cairo_stroker_t *stroker = closure; - cairo_status_t status; - - /* reset the dash pattern for new sub paths */ - _cairo_stroker_dash_start (&stroker->dash); - - /* Cap the start and end of the previous sub path as needed */ - status = _cairo_stroker_add_caps (stroker); - if (unlikely (status)) - return status; - - stroker->first_point = *point; - stroker->current_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 -_cairo_stroker_line_to (void *closure, - const cairo_point_t *point) -{ - cairo_stroker_t *stroker = closure; - cairo_stroke_face_t start, end; - cairo_point_t *p1 = &stroker->current_point; - cairo_slope_t dev_slope; - double slope_dx, slope_dy; - cairo_status_t status; - - stroker->has_initial_sub_path = TRUE; - - if (p1->x == point->x && p1->y == point->y) - return CAIRO_STATUS_SUCCESS; - - _cairo_slope_init (&dev_slope, p1, point); - slope_dx = _cairo_fixed_to_double (point->x - p1->x); - slope_dy = _cairo_fixed_to_double (point->y - p1->y); - _compute_normalized_device_slope (&slope_dx, &slope_dy, - stroker->ctm_inverse, NULL); - - status = _cairo_stroker_add_sub_edge (stroker, - p1, point, - &dev_slope, - slope_dx, slope_dy, - &start, &end); - if (unlikely (status)) - return status; - - if (stroker->has_current_face) { - /* Join with final face from previous segment */ - status = _cairo_stroker_join (stroker, - &stroker->current_face, - &start); - if (unlikely (status)) - return status; - } 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; - - stroker->current_point = *point; - - return CAIRO_STATUS_SUCCESS; -} - -static cairo_status_t -_cairo_stroker_spline_to (void *closure, - const cairo_point_t *point, - const cairo_slope_t *tangent) -{ - cairo_stroker_t *stroker = closure; - cairo_stroke_face_t new_face; - double slope_dx, slope_dy; - cairo_point_t points[3]; - cairo_point_t intersect_point; - - stroker->has_initial_sub_path = TRUE; - - if (stroker->current_point.x == point->x && - stroker->current_point.y == point->y) - return CAIRO_STATUS_SUCCESS; - - slope_dx = _cairo_fixed_to_double (tangent->dx); - slope_dy = _cairo_fixed_to_double (tangent->dy); - - if (! _compute_normalized_device_slope (&slope_dx, &slope_dy, - stroker->ctm_inverse, NULL)) - return CAIRO_STATUS_SUCCESS; - - _compute_face (point, tangent, - slope_dx, slope_dy, - stroker, &new_face); - - assert (stroker->has_current_face); - - if ((new_face.dev_slope.x * stroker->current_face.dev_slope.x + - new_face.dev_slope.y * stroker->current_face.dev_slope.y) < stroker->spline_cusp_tolerance) { - - const cairo_point_t *inpt, *outpt; - int clockwise = _cairo_stroker_join_is_clockwise (&new_face, - &stroker->current_face); - - if (clockwise) { - inpt = &stroker->current_face.cw; - outpt = &new_face.cw; - } else { - inpt = &stroker->current_face.ccw; - outpt = &new_face.ccw; - } - - _tessellate_fan (stroker, - &stroker->current_face.dev_vector, - &new_face.dev_vector, - &stroker->current_face.point, - inpt, outpt, - clockwise); - } - - if (_slow_segment_intersection (&stroker->current_face.cw, - &stroker->current_face.ccw, - &new_face.cw, - &new_face.ccw, - &intersect_point)) { - points[0] = stroker->current_face.ccw; - points[1] = new_face.ccw; - points[2] = intersect_point; - stroker->add_triangle (stroker->closure, points); - - points[0] = stroker->current_face.cw; - points[1] = new_face.cw; - stroker->add_triangle (stroker->closure, points); - } else { - points[0] = stroker->current_face.ccw; - points[1] = stroker->current_face.cw; - points[2] = new_face.cw; - stroker->add_triangle (stroker->closure, points); - - points[0] = stroker->current_face.ccw; - points[1] = new_face.cw; - points[2] = new_face.ccw; - stroker->add_triangle (stroker->closure, points); - } - - stroker->current_face = new_face; - stroker->has_current_face = TRUE; - stroker->current_point = *point; - - return CAIRO_STATUS_SUCCESS; -} - -/* - * Dashed lines. Cap each dash end, join around turns when on - */ -static cairo_status_t -_cairo_stroker_line_to_dashed (void *closure, - const cairo_point_t *p2) -{ - cairo_stroker_t *stroker = closure; - double mag, remain, step_length = 0; - double slope_dx, slope_dy; - double dx2, dy2; - cairo_stroke_face_t sub_start, sub_end; - cairo_point_t *p1 = &stroker->current_point; - cairo_slope_t dev_slope; - cairo_line_t segment; - cairo_bool_t fully_in_bounds; - cairo_status_t status; - - 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->bounds, p1) || - ! _cairo_box_contains_point (&stroker->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 (! _compute_normalized_device_slope (&slope_dx, &slope_dy, - stroker->ctm_inverse, &mag)) - { - 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->bounds, &segment))) - { - status = _cairo_stroker_add_sub_edge (stroker, - &segment.p1, &segment.p2, - &dev_slope, - slope_dx, slope_dy, - &sub_start, &sub_end); - if (unlikely (status)) - return status; - - if (stroker->has_current_face) - { - /* Join with final face from previous segment */ - status = _cairo_stroker_join (stroker, - &stroker->current_face, - &sub_start); - if (unlikely (status)) - return status; - - 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 */ - status = _cairo_stroker_add_leading_cap (stroker, &sub_start); - if (unlikely (status)) - return status; - } - - if (remain) { - /* Cap dash end if not at end of segment */ - status = _cairo_stroker_add_trailing_cap (stroker, &sub_end); - if (unlikely (status)) - return status; - } else { - stroker->current_face = sub_end; - stroker->has_current_face = TRUE; - } - } else { - if (stroker->has_current_face) { - /* Cap final face from previous segment */ - status = _cairo_stroker_add_trailing_cap (stroker, - &stroker->current_face); - if (unlikely (status)) - return status; - - 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 (p2, &dev_slope, - slope_dx, slope_dy, - stroker, - &stroker->current_face); - - status = _cairo_stroker_add_leading_cap (stroker, - &stroker->current_face); - if (unlikely (status)) - return status; - - stroker->has_current_face = TRUE; - } - - stroker->current_point = *p2; - - return CAIRO_STATUS_SUCCESS; -} - -static cairo_status_t -_cairo_stroker_curve_to (void *closure, - const cairo_point_t *b, - const cairo_point_t *c, - const cairo_point_t *d) -{ - cairo_stroker_t *stroker = closure; - cairo_spline_t spline; - cairo_line_join_t line_join_save; - cairo_stroke_face_t face; - double slope_dx, slope_dy; - cairo_spline_add_point_func_t line_to; - cairo_spline_add_point_func_t spline_to; - cairo_status_t status = CAIRO_STATUS_SUCCESS; - - line_to = stroker->dash.dashed ? - (cairo_spline_add_point_func_t) _cairo_stroker_line_to_dashed : - (cairo_spline_add_point_func_t) _cairo_stroker_line_to; - - /* spline_to is only capable of rendering non-degenerate splines. */ - spline_to = stroker->dash.dashed ? - (cairo_spline_add_point_func_t) _cairo_stroker_line_to_dashed : - (cairo_spline_add_point_func_t) _cairo_stroker_spline_to; - - if (! _cairo_spline_init (&spline, - spline_to, - stroker, - &stroker->current_point, b, c, d)) - { - cairo_slope_t fallback_slope; - _cairo_slope_init (&fallback_slope, &stroker->current_point, d); - return line_to (closure, d, &fallback_slope); - } - - /* If the line width is so small that the pen is reduced to a - single point, then we have nothing to do. */ - if (stroker->pen.num_vertices <= 1) - return CAIRO_STATUS_SUCCESS; - - /* Compute the initial face */ - if (! stroker->dash.dashed || stroker->dash.dash_on) { - slope_dx = _cairo_fixed_to_double (spline.initial_slope.dx); - slope_dy = _cairo_fixed_to_double (spline.initial_slope.dy); - if (_compute_normalized_device_slope (&slope_dx, &slope_dy, - stroker->ctm_inverse, NULL)) - { - _compute_face (&stroker->current_point, - &spline.initial_slope, - slope_dx, slope_dy, - stroker, &face); - } - if (stroker->has_current_face) { - status = _cairo_stroker_join (stroker, - &stroker->current_face, &face); - if (unlikely (status)) - return status; - } else if (! stroker->has_first_face) { - stroker->first_face = face; - stroker->has_first_face = TRUE; - } - - stroker->current_face = face; - stroker->has_current_face = TRUE; - } - - /* Temporarily modify the stroker to use round joins to guarantee - * smooth stroked curves. */ - line_join_save = stroker->style.line_join; - stroker->style.line_join = CAIRO_LINE_JOIN_ROUND; - - status = _cairo_spline_decompose (&spline, stroker->tolerance); - if (unlikely (status)) - return status; - - /* And join the final face */ - if (! stroker->dash.dashed || stroker->dash.dash_on) { - slope_dx = _cairo_fixed_to_double (spline.final_slope.dx); - slope_dy = _cairo_fixed_to_double (spline.final_slope.dy); - if (_compute_normalized_device_slope (&slope_dx, &slope_dy, - stroker->ctm_inverse, NULL)) - { - _compute_face (&stroker->current_point, - &spline.final_slope, - slope_dx, slope_dy, - stroker, &face); - } - - status = _cairo_stroker_join (stroker, &stroker->current_face, &face); - if (unlikely (status)) - return status; - - stroker->current_face = face; - } - - stroker->style.line_join = line_join_save; - - return CAIRO_STATUS_SUCCESS; -} - -static cairo_status_t -_cairo_stroker_close_path (void *closure) -{ - cairo_stroker_t *stroker = closure; - cairo_status_t status; - - if (stroker->dash.dashed) - status = _cairo_stroker_line_to_dashed (stroker, &stroker->first_point); - else - status = _cairo_stroker_line_to (stroker, &stroker->first_point); - if (unlikely (status)) - return status; - - if (stroker->has_first_face && stroker->has_current_face) { - /* Join first and final faces of sub path */ - status = _cairo_stroker_join (stroker, - &stroker->current_face, - &stroker->first_face); - if (unlikely (status)) - return status; - } else { - /* Cap the start and end of the sub path as needed */ - status = _cairo_stroker_add_caps (stroker); - if (unlikely (status)) - return status; - } - - stroker->has_initial_sub_path = FALSE; - stroker->has_first_face = FALSE; - stroker->has_current_face = FALSE; - - return CAIRO_STATUS_SUCCESS; -} - -cairo_status_t -_cairo_path_fixed_stroke_to_shaper (cairo_path_fixed_t *path, - const cairo_stroke_style_t *stroke_style, - const cairo_matrix_t *ctm, - const cairo_matrix_t *ctm_inverse, - double tolerance, - cairo_status_t (*add_triangle) (void *closure, - const cairo_point_t triangle[3]), - cairo_status_t (*add_triangle_fan) (void *closure, - const cairo_point_t *midpt, - const cairo_point_t *points, - int npoints), - cairo_status_t (*add_convex_quad) (void *closure, - const cairo_point_t quad[4]), - void *closure) -{ - cairo_stroker_t stroker; - cairo_status_t status; - - status = _cairo_stroker_init (&stroker, path, stroke_style, - ctm, ctm_inverse, tolerance, - NULL, 0); - if (unlikely (status)) - return status; - - stroker.add_triangle = add_triangle; - stroker.add_triangle_fan = add_triangle_fan; - stroker.add_convex_quad = add_convex_quad; - stroker.closure = closure; - - status = _cairo_path_fixed_interpret (path, - _cairo_stroker_move_to, - stroker.dash.dashed ? - _cairo_stroker_line_to_dashed : - _cairo_stroker_line_to, - _cairo_stroker_curve_to, - _cairo_stroker_close_path, - &stroker); - - if (unlikely (status)) - goto BAIL; - - /* Cap the start and end of the final sub path as needed */ - status = _cairo_stroker_add_caps (&stroker); - -BAIL: - _cairo_stroker_fini (&stroker); - - return status; -} - -cairo_status_t -_cairo_path_fixed_stroke_dashed_to_polygon (const cairo_path_fixed_t *path, - const cairo_stroke_style_t *stroke_style, - const cairo_matrix_t *ctm, - const cairo_matrix_t *ctm_inverse, - double tolerance, - cairo_polygon_t *polygon) -{ - cairo_stroker_t stroker; - cairo_status_t status; - - status = _cairo_stroker_init (&stroker, path, stroke_style, - ctm, ctm_inverse, tolerance, - polygon->limits, polygon->num_limits); - if (unlikely (status)) - return status; - - stroker.add_external_edge = _cairo_polygon_add_external_edge, - stroker.closure = polygon; - - status = _cairo_path_fixed_interpret (path, - _cairo_stroker_move_to, - stroker.dash.dashed ? - _cairo_stroker_line_to_dashed : - _cairo_stroker_line_to, - _cairo_stroker_curve_to, - _cairo_stroker_close_path, - &stroker); - - if (unlikely (status)) - goto BAIL; - - /* Cap the start and end of the final sub path as needed */ - status = _cairo_stroker_add_caps (&stroker); - -BAIL: - _cairo_stroker_fini (&stroker); - - return status; -} - -cairo_int_status_t -_cairo_path_fixed_stroke_polygon_to_traps (const cairo_path_fixed_t *path, - const cairo_stroke_style_t *stroke_style, - const cairo_matrix_t *ctm, - const cairo_matrix_t *ctm_inverse, - double tolerance, - cairo_traps_t *traps) -{ - cairo_int_status_t status; - cairo_polygon_t polygon; - - _cairo_polygon_init (&polygon, traps->limits, traps->num_limits); - status = _cairo_path_fixed_stroke_to_polygon (path, - stroke_style, - ctm, - ctm_inverse, - tolerance, - &polygon); - if (unlikely (status)) - goto BAIL; - - status = _cairo_polygon_status (&polygon); - if (unlikely (status)) - goto BAIL; - - status = _cairo_bentley_ottmann_tessellate_polygon (traps, &polygon, - CAIRO_FILL_RULE_WINDING); - -BAIL: - _cairo_polygon_fini (&polygon); - - return status; -} |