diff options
author | sanine <sanine.not@pm.me> | 2022-10-12 12:03:23 -0500 |
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committer | sanine <sanine.not@pm.me> | 2022-10-12 12:03:23 -0500 |
commit | 530ffd0b7d3c39757b20f00716e486b5caf89aff (patch) | |
tree | 76b35fdf57317038acf6b828871f6ae25fce2ebe /libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c | |
parent | 3dbe9332e47c143a237db12440f134caebd1cfbe (diff) |
add cairo
Diffstat (limited to 'libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c')
-rw-r--r-- | libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c b/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c new file mode 100644 index 0000000..7c0be69 --- /dev/null +++ b/libs/cairo-1.16.0/src/cairo-bentley-ottmann-rectilinear.c @@ -0,0 +1,600 @@ +/* + * Copyright © 2004 Carl Worth + * Copyright © 2006 Red Hat, Inc. + * Copyright © 2008 Chris Wilson + * + * 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> + */ + +/* Provide definitions for standalone compilation */ +#include "cairoint.h" + +#include "cairo-boxes-private.h" +#include "cairo-combsort-inline.h" +#include "cairo-error-private.h" +#include "cairo-traps-private.h" + +typedef struct _cairo_bo_edge cairo_bo_edge_t; +typedef struct _cairo_bo_trap cairo_bo_trap_t; + +/* A deferred trapezoid of an edge */ +struct _cairo_bo_trap { + cairo_bo_edge_t *right; + int32_t top; +}; + +struct _cairo_bo_edge { + cairo_edge_t edge; + cairo_bo_edge_t *prev; + cairo_bo_edge_t *next; + cairo_bo_trap_t deferred_trap; +}; + +typedef enum { + CAIRO_BO_EVENT_TYPE_START, + CAIRO_BO_EVENT_TYPE_STOP +} cairo_bo_event_type_t; + +typedef struct _cairo_bo_event { + cairo_bo_event_type_t type; + cairo_point_t point; + cairo_bo_edge_t *edge; +} cairo_bo_event_t; + +typedef struct _cairo_bo_sweep_line { + cairo_bo_event_t **events; + cairo_bo_edge_t *head; + cairo_bo_edge_t *stopped; + int32_t current_y; + cairo_bo_edge_t *current_edge; +} cairo_bo_sweep_line_t; + +static inline int +_cairo_point_compare (const cairo_point_t *a, + const cairo_point_t *b) +{ + int cmp; + + cmp = a->y - b->y; + if (likely (cmp)) + return cmp; + + return a->x - b->x; +} + +static inline int +_cairo_bo_edge_compare (const cairo_bo_edge_t *a, + const cairo_bo_edge_t *b) +{ + int cmp; + + cmp = a->edge.line.p1.x - b->edge.line.p1.x; + if (likely (cmp)) + return cmp; + + return b->edge.bottom - a->edge.bottom; +} + +static inline int +cairo_bo_event_compare (const cairo_bo_event_t *a, + const cairo_bo_event_t *b) +{ + int cmp; + + cmp = _cairo_point_compare (&a->point, &b->point); + if (likely (cmp)) + return cmp; + + cmp = a->type - b->type; + if (cmp) + return cmp; + + return a - b; +} + +static inline cairo_bo_event_t * +_cairo_bo_event_dequeue (cairo_bo_sweep_line_t *sweep_line) +{ + return *sweep_line->events++; +} + +CAIRO_COMBSORT_DECLARE (_cairo_bo_event_queue_sort, + cairo_bo_event_t *, + cairo_bo_event_compare) + +static void +_cairo_bo_sweep_line_init (cairo_bo_sweep_line_t *sweep_line, + cairo_bo_event_t **events, + int num_events) +{ + _cairo_bo_event_queue_sort (events, num_events); + events[num_events] = NULL; + sweep_line->events = events; + + sweep_line->head = NULL; + sweep_line->current_y = INT32_MIN; + sweep_line->current_edge = NULL; +} + +static void +_cairo_bo_sweep_line_insert (cairo_bo_sweep_line_t *sweep_line, + cairo_bo_edge_t *edge) +{ + if (sweep_line->current_edge != NULL) { + cairo_bo_edge_t *prev, *next; + int cmp; + + cmp = _cairo_bo_edge_compare (sweep_line->current_edge, edge); + if (cmp < 0) { + prev = sweep_line->current_edge; + next = prev->next; + while (next != NULL && _cairo_bo_edge_compare (next, edge) < 0) + prev = next, next = prev->next; + + prev->next = edge; + edge->prev = prev; + edge->next = next; + if (next != NULL) + next->prev = edge; + } else if (cmp > 0) { + next = sweep_line->current_edge; + prev = next->prev; + while (prev != NULL && _cairo_bo_edge_compare (prev, edge) > 0) + next = prev, prev = next->prev; + + next->prev = edge; + edge->next = next; + edge->prev = prev; + if (prev != NULL) + prev->next = edge; + else + sweep_line->head = edge; + } else { + prev = sweep_line->current_edge; + edge->prev = prev; + edge->next = prev->next; + if (prev->next != NULL) + prev->next->prev = edge; + prev->next = edge; + } + } else { + sweep_line->head = edge; + } + + sweep_line->current_edge = edge; +} + +static void +_cairo_bo_sweep_line_delete (cairo_bo_sweep_line_t *sweep_line, + cairo_bo_edge_t *edge) +{ + if (edge->prev != NULL) + edge->prev->next = edge->next; + else + sweep_line->head = edge->next; + + if (edge->next != NULL) + edge->next->prev = edge->prev; + + if (sweep_line->current_edge == edge) + sweep_line->current_edge = edge->prev ? edge->prev : edge->next; +} + +static inline cairo_bool_t +edges_collinear (const cairo_bo_edge_t *a, const cairo_bo_edge_t *b) +{ + return a->edge.line.p1.x == b->edge.line.p1.x; +} + +static cairo_status_t +_cairo_bo_edge_end_trap (cairo_bo_edge_t *left, + int32_t bot, + cairo_bool_t do_traps, + void *container) +{ + cairo_bo_trap_t *trap = &left->deferred_trap; + cairo_status_t status = CAIRO_STATUS_SUCCESS; + + /* Only emit (trivial) non-degenerate trapezoids with positive height. */ + if (likely (trap->top < bot)) { + if (do_traps) { + _cairo_traps_add_trap (container, + trap->top, bot, + &left->edge.line, &trap->right->edge.line); + status = _cairo_traps_status ((cairo_traps_t *) container); + } else { + cairo_box_t box; + + box.p1.x = left->edge.line.p1.x; + box.p1.y = trap->top; + box.p2.x = trap->right->edge.line.p1.x; + box.p2.y = bot; + status = _cairo_boxes_add (container, CAIRO_ANTIALIAS_DEFAULT, &box); + } + } + + trap->right = NULL; + + return status; +} + +/* Start a new trapezoid at the given top y coordinate, whose edges + * are `edge' and `edge->next'. If `edge' already has a trapezoid, + * then either add it to the traps in `traps', if the trapezoid's + * right edge differs from `edge->next', or do nothing if the new + * trapezoid would be a continuation of the existing one. */ +static inline cairo_status_t +_cairo_bo_edge_start_or_continue_trap (cairo_bo_edge_t *left, + cairo_bo_edge_t *right, + int top, + cairo_bool_t do_traps, + void *container) +{ + cairo_status_t status; + + if (left->deferred_trap.right == right) + return CAIRO_STATUS_SUCCESS; + + if (left->deferred_trap.right != NULL) { + if (right != NULL && edges_collinear (left->deferred_trap.right, right)) + { + /* continuation on right, so just swap edges */ + left->deferred_trap.right = right; + return CAIRO_STATUS_SUCCESS; + } + + status = _cairo_bo_edge_end_trap (left, top, do_traps, container); + if (unlikely (status)) + return status; + } + + if (right != NULL && ! edges_collinear (left, right)) { + left->deferred_trap.top = top; + left->deferred_trap.right = right; + } + + return CAIRO_STATUS_SUCCESS; +} + +static inline cairo_status_t +_active_edges_to_traps (cairo_bo_edge_t *left, + int32_t top, + cairo_fill_rule_t fill_rule, + cairo_bool_t do_traps, + void *container) +{ + cairo_bo_edge_t *right; + cairo_status_t status; + + if (fill_rule == CAIRO_FILL_RULE_WINDING) { + while (left != NULL) { + int in_out; + + /* Greedily search for the closing edge, so that we generate the + * maximal span width with the minimal number of trapezoids. + */ + in_out = left->edge.dir; + + /* Check if there is a co-linear edge with an existing trap */ + right = left->next; + if (left->deferred_trap.right == NULL) { + while (right != NULL && right->deferred_trap.right == NULL) + right = right->next; + + if (right != NULL && edges_collinear (left, right)) { + /* continuation on left */ + left->deferred_trap = right->deferred_trap; + right->deferred_trap.right = NULL; + } + } + + /* End all subsumed traps */ + right = left->next; + while (right != NULL) { + if (right->deferred_trap.right != NULL) { + status = _cairo_bo_edge_end_trap (right, top, do_traps, container); + if (unlikely (status)) + return status; + } + + in_out += right->edge.dir; + if (in_out == 0) { + /* skip co-linear edges */ + if (right->next == NULL || + ! edges_collinear (right, right->next)) + { + break; + } + } + + right = right->next; + } + + status = _cairo_bo_edge_start_or_continue_trap (left, right, top, + do_traps, container); + if (unlikely (status)) + return status; + + left = right; + if (left != NULL) + left = left->next; + } + } else { + while (left != NULL) { + int in_out = 0; + + right = left->next; + while (right != NULL) { + if (right->deferred_trap.right != NULL) { + status = _cairo_bo_edge_end_trap (right, top, do_traps, container); + if (unlikely (status)) + return status; + } + + if ((in_out++ & 1) == 0) { + cairo_bo_edge_t *next; + cairo_bool_t skip = FALSE; + + /* skip co-linear edges */ + next = right->next; + if (next != NULL) + skip = edges_collinear (right, next); + + if (! skip) + break; + } + + right = right->next; + } + + status = _cairo_bo_edge_start_or_continue_trap (left, right, top, + do_traps, container); + if (unlikely (status)) + return status; + + left = right; + if (left != NULL) + left = left->next; + } + } + + return CAIRO_STATUS_SUCCESS; +} + +static cairo_status_t +_cairo_bentley_ottmann_tessellate_rectilinear (cairo_bo_event_t **start_events, + int num_events, + cairo_fill_rule_t fill_rule, + cairo_bool_t do_traps, + void *container) +{ + cairo_bo_sweep_line_t sweep_line; + cairo_bo_event_t *event; + cairo_status_t status; + + _cairo_bo_sweep_line_init (&sweep_line, start_events, num_events); + + while ((event = _cairo_bo_event_dequeue (&sweep_line))) { + if (event->point.y != sweep_line.current_y) { + status = _active_edges_to_traps (sweep_line.head, + sweep_line.current_y, + fill_rule, do_traps, container); + if (unlikely (status)) + return status; + + sweep_line.current_y = event->point.y; + } + + switch (event->type) { + case CAIRO_BO_EVENT_TYPE_START: + _cairo_bo_sweep_line_insert (&sweep_line, event->edge); + break; + + case CAIRO_BO_EVENT_TYPE_STOP: + _cairo_bo_sweep_line_delete (&sweep_line, event->edge); + + if (event->edge->deferred_trap.right != NULL) { + status = _cairo_bo_edge_end_trap (event->edge, + sweep_line.current_y, + do_traps, container); + if (unlikely (status)) + return status; + } + + break; + } + } + + return CAIRO_STATUS_SUCCESS; +} + +cairo_status_t +_cairo_bentley_ottmann_tessellate_rectilinear_polygon_to_boxes (const cairo_polygon_t *polygon, + cairo_fill_rule_t fill_rule, + cairo_boxes_t *boxes) +{ + cairo_status_t status; + cairo_bo_event_t stack_events[CAIRO_STACK_ARRAY_LENGTH (cairo_bo_event_t)]; + cairo_bo_event_t *events; + cairo_bo_event_t *stack_event_ptrs[ARRAY_LENGTH (stack_events) + 1]; + cairo_bo_event_t **event_ptrs; + cairo_bo_edge_t stack_edges[ARRAY_LENGTH (stack_events)]; + cairo_bo_edge_t *edges; + int num_events; + int i, j; + + if (unlikely (polygon->num_edges == 0)) + return CAIRO_STATUS_SUCCESS; + + num_events = 2 * polygon->num_edges; + + events = stack_events; + event_ptrs = stack_event_ptrs; + edges = stack_edges; + if (num_events > ARRAY_LENGTH (stack_events)) { + events = _cairo_malloc_ab_plus_c (num_events, + sizeof (cairo_bo_event_t) + + sizeof (cairo_bo_edge_t) + + sizeof (cairo_bo_event_t *), + sizeof (cairo_bo_event_t *)); + if (unlikely (events == NULL)) + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + + event_ptrs = (cairo_bo_event_t **) (events + num_events); + edges = (cairo_bo_edge_t *) (event_ptrs + num_events + 1); + } + + for (i = j = 0; i < polygon->num_edges; i++) { + edges[i].edge = polygon->edges[i]; + edges[i].deferred_trap.right = NULL; + edges[i].prev = NULL; + edges[i].next = NULL; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_START; + events[j].point.y = polygon->edges[i].top; + events[j].point.x = polygon->edges[i].line.p1.x; + events[j].edge = &edges[i]; + j++; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_STOP; + events[j].point.y = polygon->edges[i].bottom; + events[j].point.x = polygon->edges[i].line.p1.x; + events[j].edge = &edges[i]; + j++; + } + + status = _cairo_bentley_ottmann_tessellate_rectilinear (event_ptrs, j, + fill_rule, + FALSE, boxes); + if (events != stack_events) + free (events); + + return status; +} + +cairo_status_t +_cairo_bentley_ottmann_tessellate_rectilinear_traps (cairo_traps_t *traps, + cairo_fill_rule_t fill_rule) +{ + cairo_bo_event_t stack_events[CAIRO_STACK_ARRAY_LENGTH (cairo_bo_event_t)]; + cairo_bo_event_t *events; + cairo_bo_event_t *stack_event_ptrs[ARRAY_LENGTH (stack_events) + 1]; + cairo_bo_event_t **event_ptrs; + cairo_bo_edge_t stack_edges[ARRAY_LENGTH (stack_events)]; + cairo_bo_edge_t *edges; + cairo_status_t status; + int i, j, k; + + if (unlikely (traps->num_traps == 0)) + return CAIRO_STATUS_SUCCESS; + + assert (traps->is_rectilinear); + + i = 4 * traps->num_traps; + + events = stack_events; + event_ptrs = stack_event_ptrs; + edges = stack_edges; + if (i > ARRAY_LENGTH (stack_events)) { + events = _cairo_malloc_ab_plus_c (i, + sizeof (cairo_bo_event_t) + + sizeof (cairo_bo_edge_t) + + sizeof (cairo_bo_event_t *), + sizeof (cairo_bo_event_t *)); + if (unlikely (events == NULL)) + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + + event_ptrs = (cairo_bo_event_t **) (events + i); + edges = (cairo_bo_edge_t *) (event_ptrs + i + 1); + } + + for (i = j = k = 0; i < traps->num_traps; i++) { + edges[k].edge.top = traps->traps[i].top; + edges[k].edge.bottom = traps->traps[i].bottom; + edges[k].edge.line = traps->traps[i].left; + edges[k].edge.dir = 1; + edges[k].deferred_trap.right = NULL; + edges[k].prev = NULL; + edges[k].next = NULL; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_START; + events[j].point.y = traps->traps[i].top; + events[j].point.x = traps->traps[i].left.p1.x; + events[j].edge = &edges[k]; + j++; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_STOP; + events[j].point.y = traps->traps[i].bottom; + events[j].point.x = traps->traps[i].left.p1.x; + events[j].edge = &edges[k]; + j++; + k++; + + edges[k].edge.top = traps->traps[i].top; + edges[k].edge.bottom = traps->traps[i].bottom; + edges[k].edge.line = traps->traps[i].right; + edges[k].edge.dir = -1; + edges[k].deferred_trap.right = NULL; + edges[k].prev = NULL; + edges[k].next = NULL; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_START; + events[j].point.y = traps->traps[i].top; + events[j].point.x = traps->traps[i].right.p1.x; + events[j].edge = &edges[k]; + j++; + + event_ptrs[j] = &events[j]; + events[j].type = CAIRO_BO_EVENT_TYPE_STOP; + events[j].point.y = traps->traps[i].bottom; + events[j].point.x = traps->traps[i].right.p1.x; + events[j].edge = &edges[k]; + j++; + k++; + } + + _cairo_traps_clear (traps); + status = _cairo_bentley_ottmann_tessellate_rectilinear (event_ptrs, j, + fill_rule, + TRUE, traps); + traps->is_rectilinear = TRUE; + + if (events != stack_events) + free (events); + + return status; +} |