diff options
Diffstat (limited to 'libs/cairo-1.16.0/src/cairo-contour.c')
-rw-r--r-- | libs/cairo-1.16.0/src/cairo-contour.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/libs/cairo-1.16.0/src/cairo-contour.c b/libs/cairo-1.16.0/src/cairo-contour.c new file mode 100644 index 0000000..9ad75bd --- /dev/null +++ b/libs/cairo-1.16.0/src/cairo-contour.c @@ -0,0 +1,453 @@ +/* + * Copyright © 2004 Carl Worth + * Copyright © 2006 Red Hat, Inc. + * Copyright © 2008 Chris Wilson + * Copyright © 2011 Intel Corporation + * + * 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 Carl Worth + * + * Contributor(s): + * Carl D. Worth <cworth@cworth.org> + * Chris Wilson <chris@chris-wilson.co.uk> + */ + +#include "cairoint.h" + +#include "cairo-error-private.h" +#include "cairo-freelist-private.h" +#include "cairo-combsort-inline.h" +#include "cairo-contour-inline.h" +#include "cairo-contour-private.h" + +void +_cairo_contour_init (cairo_contour_t *contour, + int direction) +{ + contour->direction = direction; + contour->chain.points = contour->embedded_points; + contour->chain.next = NULL; + contour->chain.num_points = 0; + contour->chain.size_points = ARRAY_LENGTH (contour->embedded_points); + contour->tail = &contour->chain; +} + +cairo_int_status_t +__cairo_contour_add_point (cairo_contour_t *contour, + const cairo_point_t *point) +{ + cairo_contour_chain_t *tail = contour->tail; + cairo_contour_chain_t *next; + + assert (tail->next == NULL); + + next = _cairo_malloc_ab_plus_c (tail->size_points*2, + sizeof (cairo_point_t), + sizeof (cairo_contour_chain_t)); + if (unlikely (next == NULL)) + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + + next->size_points = tail->size_points*2; + next->num_points = 1; + next->points = (cairo_point_t *)(next+1); + next->next = NULL; + tail->next = next; + contour->tail = next; + + next->points[0] = *point; + return CAIRO_INT_STATUS_SUCCESS; +} + +static void +first_inc (cairo_contour_t *contour, + cairo_point_t **p, + cairo_contour_chain_t **chain) +{ + if (*p == (*chain)->points + (*chain)->num_points) { + assert ((*chain)->next); + *chain = (*chain)->next; + *p = &(*chain)->points[0]; + } else + ++*p; +} + +static void +last_dec (cairo_contour_t *contour, + cairo_point_t **p, + cairo_contour_chain_t **chain) +{ + if (*p == (*chain)->points) { + cairo_contour_chain_t *prev; + assert (*chain != &contour->chain); + for (prev = &contour->chain; prev->next != *chain; prev = prev->next) + ; + *chain = prev; + *p = &(*chain)->points[(*chain)->num_points-1]; + } else + --*p; +} + +void +_cairo_contour_reverse (cairo_contour_t *contour) +{ + cairo_contour_chain_t *first_chain, *last_chain; + cairo_point_t *first, *last; + + contour->direction = -contour->direction; + + if (contour->chain.num_points <= 1) + return; + + first_chain = &contour->chain; + last_chain = contour->tail; + + first = &first_chain->points[0]; + last = &last_chain->points[last_chain->num_points-1]; + + while (first != last) { + cairo_point_t p; + + p = *first; + *first = *last; + *last = p; + + first_inc (contour, &first, &first_chain); + last_dec (contour, &last, &last_chain); + } +} + +cairo_int_status_t +_cairo_contour_add (cairo_contour_t *dst, + const cairo_contour_t *src) +{ + const cairo_contour_chain_t *chain; + cairo_int_status_t status; + int i; + + for (chain = &src->chain; chain; chain = chain->next) { + for (i = 0; i < chain->num_points; i++) { + status = _cairo_contour_add_point (dst, &chain->points[i]); + if (unlikely (status)) + return status; + } + } + + return CAIRO_INT_STATUS_SUCCESS; +} + +static inline cairo_bool_t +iter_next (cairo_contour_iter_t *iter) +{ + if (iter->point == &iter->chain->points[iter->chain->size_points-1]) { + iter->chain = iter->chain->next; + if (iter->chain == NULL) + return FALSE; + + iter->point = &iter->chain->points[0]; + return TRUE; + } else { + iter->point++; + return TRUE; + } +} + +static cairo_bool_t +iter_equal (const cairo_contour_iter_t *i1, + const cairo_contour_iter_t *i2) +{ + return i1->chain == i2->chain && i1->point == i2->point; +} + +static void +iter_init (cairo_contour_iter_t *iter, cairo_contour_t *contour) +{ + iter->chain = &contour->chain; + iter->point = &contour->chain.points[0]; +} + +static void +iter_init_last (cairo_contour_iter_t *iter, cairo_contour_t *contour) +{ + iter->chain = contour->tail; + iter->point = &contour->tail->points[contour->tail->num_points-1]; +} + +static const cairo_contour_chain_t *prev_const_chain(const cairo_contour_t *contour, + const cairo_contour_chain_t *chain) +{ + const cairo_contour_chain_t *prev; + + if (chain == &contour->chain) + return NULL; + + for (prev = &contour->chain; prev->next != chain; prev = prev->next) + ; + + return prev; +} + +cairo_int_status_t +_cairo_contour_add_reversed (cairo_contour_t *dst, + const cairo_contour_t *src) +{ + const cairo_contour_chain_t *last; + cairo_int_status_t status; + int i; + + if (src->chain.num_points == 0) + return CAIRO_INT_STATUS_SUCCESS; + + for (last = src->tail; last; last = prev_const_chain (src, last)) { + for (i = last->num_points-1; i >= 0; i--) { + status = _cairo_contour_add_point (dst, &last->points[i]); + if (unlikely (status)) + return status; + } + } + + return CAIRO_INT_STATUS_SUCCESS; +} + +static cairo_uint64_t +point_distance_sq (const cairo_point_t *p1, + const cairo_point_t *p2) +{ + int32_t dx = p1->x - p2->x; + int32_t dy = p1->y - p2->y; + return _cairo_int32x32_64_mul (dx, dx) + _cairo_int32x32_64_mul (dy, dy); +} + +#define DELETED(p) ((p)->x == INT_MIN && (p)->y == INT_MAX) +#define MARK_DELETED(p) ((p)->x = INT_MIN, (p)->y = INT_MAX) + +static cairo_bool_t +_cairo_contour_simplify_chain (cairo_contour_t *contour, const double tolerance, + const cairo_contour_iter_t *first, + const cairo_contour_iter_t *last) +{ + cairo_contour_iter_t iter, furthest; + uint64_t max_error; + int x0, y0; + int nx, ny; + int count; + + iter = *first; + iter_next (&iter); + if (iter_equal (&iter, last)) + return FALSE; + + x0 = first->point->x; + y0 = first->point->y; + nx = last->point->y - y0; + ny = x0 - last->point->x; + + count = 0; + max_error = 0; + do { + cairo_point_t *p = iter.point; + if (! DELETED(p)) { + uint64_t d = (uint64_t)nx * (x0 - p->x) + (uint64_t)ny * (y0 - p->y); + if (d * d > max_error) { + max_error = d * d; + furthest = iter; + } + count++; + } + iter_next (&iter); + } while (! iter_equal (&iter, last)); + if (count == 0) + return FALSE; + + if (max_error > tolerance * ((uint64_t)nx * nx + (uint64_t)ny * ny)) { + cairo_bool_t simplified; + + simplified = FALSE; + simplified |= _cairo_contour_simplify_chain (contour, tolerance, + first, &furthest); + simplified |= _cairo_contour_simplify_chain (contour, tolerance, + &furthest, last); + return simplified; + } else { + iter = *first; + iter_next (&iter); + do { + MARK_DELETED (iter.point); + iter_next (&iter); + } while (! iter_equal (&iter, last)); + + return TRUE; + } +} + +void +_cairo_contour_simplify (cairo_contour_t *contour, double tolerance) +{ + cairo_contour_chain_t *chain; + cairo_point_t *last = NULL; + cairo_contour_iter_t iter, furthest; + cairo_bool_t simplified; + uint64_t max = 0; + int i; + + if (contour->chain.num_points <= 2) + return; + + tolerance = tolerance * CAIRO_FIXED_ONE; + tolerance *= tolerance; + + /* stage 1: vertex reduction */ + for (chain = &contour->chain; chain; chain = chain->next) { + for (i = 0; i < chain->num_points; i++) { + if (last == NULL || + point_distance_sq (last, &chain->points[i]) > tolerance) { + last = &chain->points[i]; + } else { + MARK_DELETED (&chain->points[i]); + } + } + } + + /* stage2: polygon simplification using Douglas-Peucker */ + do { + last = &contour->chain.points[0]; + iter_init (&furthest, contour); + max = 0; + for (chain = &contour->chain; chain; chain = chain->next) { + for (i = 0; i < chain->num_points; i++) { + uint64_t d; + + if (DELETED (&chain->points[i])) + continue; + + d = point_distance_sq (last, &chain->points[i]); + if (d > max) { + furthest.chain = chain; + furthest.point = &chain->points[i]; + max = d; + } + } + } + assert (max); + + simplified = FALSE; + iter_init (&iter, contour); + simplified |= _cairo_contour_simplify_chain (contour, tolerance, + &iter, &furthest); + + iter_init_last (&iter, contour); + if (! iter_equal (&furthest, &iter)) + simplified |= _cairo_contour_simplify_chain (contour, tolerance, + &furthest, &iter); + } while (simplified); + + iter_init (&iter, contour); + for (chain = &contour->chain; chain; chain = chain->next) { + int num_points = chain->num_points; + chain->num_points = 0; + for (i = 0; i < num_points; i++) { + if (! DELETED(&chain->points[i])) { + if (iter.point != &chain->points[i]) + *iter.point = chain->points[i]; + iter.chain->num_points++; + iter_next (&iter); + } + } + } + + if (iter.chain) { + cairo_contour_chain_t *next; + + for (chain = iter.chain->next; chain; chain = next) { + next = chain->next; + free (chain); + } + + iter.chain->next = NULL; + contour->tail = iter.chain; + } +} + +void +_cairo_contour_reset (cairo_contour_t *contour) +{ + _cairo_contour_fini (contour); + _cairo_contour_init (contour, contour->direction); +} + +void +_cairo_contour_fini (cairo_contour_t *contour) +{ + cairo_contour_chain_t *chain, *next; + + for (chain = contour->chain.next; chain; chain = next) { + next = chain->next; + free (chain); + } +} + +void +_cairo_debug_print_contour (FILE *file, cairo_contour_t *contour) +{ + cairo_contour_chain_t *chain; + int num_points, size_points; + int i; + + num_points = 0; + size_points = 0; + for (chain = &contour->chain; chain; chain = chain->next) { + num_points += chain->num_points; + size_points += chain->size_points; + } + + fprintf (file, "contour: direction=%d, num_points=%d / %d\n", + contour->direction, num_points, size_points); + + num_points = 0; + for (chain = &contour->chain; chain; chain = chain->next) { + for (i = 0; i < chain->num_points; i++) { + fprintf (file, " [%d] = (%f, %f)\n", + num_points++, + _cairo_fixed_to_double (chain->points[i].x), + _cairo_fixed_to_double (chain->points[i].y)); + } + } +} + +void +__cairo_contour_remove_last_chain (cairo_contour_t *contour) +{ + cairo_contour_chain_t *chain; + + if (contour->tail == &contour->chain) + return; + + for (chain = &contour->chain; chain->next != contour->tail; chain = chain->next) + ; + free (contour->tail); + contour->tail = chain; + chain->next = NULL; +} |