From f228769dfe5a8b5d73c49a41e95e31ed73a77fb3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 08 Jun 2012 16:22:41 +0000 Subject: polygon-reduce: Reduce broken stopped-edge continuation This is hopefully a lesser used path and the attempted optimisation to continue a stopped edge with a colinear stopped edge highly unlikely and lost in the noise of the general inefficiency of the routine. As it was broken, rather than attempt to rectify the "optimisation" remove it. Reported-by: Evangelos Foutras Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50852 Signed-off-by: Chris Wilson --- diff --git a/src/cairo-polygon-reduce.c b/src/cairo-polygon-reduce.c index 8758070..ea457fe 100644 --- a/src/cairo-polygon-reduce.c +++ b/src/cairo-polygon-reduce.c @@ -42,6 +42,8 @@ #include "cairo-freelist-private.h" #include "cairo-combsort-inline.h" +#define DEBUG_POLYGON 0 + typedef cairo_point_t cairo_bo_point32_t; typedef struct _cairo_bo_intersect_ordinate { @@ -114,7 +116,6 @@ typedef struct _cairo_bo_event_queue { typedef struct _cairo_bo_sweep_line { 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; @@ -476,8 +477,8 @@ edges_compare_x_for_y (const cairo_bo_edge_t *a, static inline int _line_equal (const cairo_line_t *a, const cairo_line_t *b) { - return a->p1.x == b->p1.x && a->p1.y == b->p1.y && - a->p2.x == b->p2.x && a->p2.y == b->p2.y; + return (a->p1.x == b->p1.x && a->p1.y == b->p1.y && + a->p2.x == b->p2.x && a->p2.y == b->p2.y); } static int @@ -1024,7 +1025,6 @@ static void _cairo_bo_sweep_line_init (cairo_bo_sweep_line_t *sweep_line) { sweep_line->head = NULL; - sweep_line->stopped = NULL; sweep_line->current_y = INT32_MIN; sweep_line->current_edge = NULL; } @@ -1139,6 +1139,8 @@ edges_colinear (const cairo_bo_edge_t *a, const cairo_bo_edge_t *b) */ if (a->edge.line.p1.y == b->edge.line.p1.y) { return a->edge.line.p1.x == b->edge.line.p1.x; + } else if (a->edge.line.p2.y == b->edge.line.p2.y) { + return a->edge.line.p2.x == b->edge.line.p2.x; } else if (a->edge.line.p1.y < b->edge.line.p1.y) { return edge_compare_for_y_against_x (b, a->edge.line.p1.y, @@ -1205,82 +1207,48 @@ _active_edges_to_polygon (cairo_bo_edge_t *left, cairo_polygon_t *polygon) { cairo_bo_edge_t *right; + unsigned int mask; - if (fill_rule == CAIRO_FILL_RULE_WINDING) { - while (left != NULL) { - int in_out = left->edge.dir; - - right = left->next; - if (left->deferred.right == NULL) { - while (right != NULL && right->deferred.right == NULL) - right = right->next; - - if (right != NULL && edges_colinear (left, right)) { - /* continuation on left */ - left->deferred = right->deferred; - right->deferred.right = NULL; - } - } - - right = left->next; - while (right != NULL) { - if (right->deferred.right != NULL) - _cairo_bo_edge_end (right, top, polygon); - - in_out += right->edge.dir; - if (in_out == 0) { - cairo_bo_edge_t *next; - cairo_bool_t skip = FALSE; - - /* skip co-linear edges */ - next = right->next; - if (next != NULL) - skip = edges_colinear (right, next); + if (fill_rule == CAIRO_FILL_RULE_WINDING) + mask = ~0; + else + mask = 1; - if (! skip) - break; - } + while (left != NULL) { + int in_out = left->edge.dir; + right = left->next; + if (left->deferred.right == NULL) { + while (right != NULL && right->deferred.right == NULL) right = right->next; - } - - _cairo_bo_edge_start_or_continue (left, right, top, polygon); - left = right; - if (left != NULL) - left = left->next; + if (right != NULL && edges_colinear (left, right)) { + /* continuation on left */ + left->deferred = right->deferred; + right->deferred.right = NULL; + } } - } else { - while (left != NULL) { - int in_out = 0; - right = left->next; - while (right != NULL) { - if (right->deferred.right != NULL) - _cairo_bo_edge_end (right, top, polygon); + right = left->next; + while (right != NULL) { + if (right->deferred.right != NULL) + _cairo_bo_edge_end (right, top, polygon); - 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_colinear (right, next); - - if (! skip) - break; - } - - right = right->next; + in_out += right->edge.dir; + if ((in_out & mask) == 0) { + /* skip co-linear edges */ + if (right->next == NULL || !edges_colinear (right, right->next)) + break; } - _cairo_bo_edge_start_or_continue (left, right, top, polygon); - - left = right; - if (left != NULL) - left = left->next; + right = right->next; } + + _cairo_bo_edge_start_or_continue (left, right, top, polygon); + + left = right; + if (left != NULL) + left = left->next; } } @@ -1303,12 +1271,6 @@ _cairo_bentley_ottmann_tessellate_bo_edges (cairo_bo_event_t **start_events, while ((event = _cairo_bo_event_dequeue (&event_queue))) { if (event->point.y != sweep_line.current_y) { - for (e1 = sweep_line.stopped; e1; e1 = e1->next) { - if (e1->deferred.right != NULL) - _cairo_bo_edge_end (e1, e1->edge.bottom, polygon); - } - sweep_line.stopped = NULL; - _active_edges_to_polygon (sweep_line.head, sweep_line.current_y, fill_rule, polygon); @@ -1328,23 +1290,6 @@ _cairo_bentley_ottmann_tessellate_bo_edges (cairo_bo_event_t **start_events, if (unlikely (status)) goto unwind; - /* check to see if this is a continuation of a stopped edge */ - /* XXX change to an infinitesimal lengthening rule */ - for (left = sweep_line.stopped; left; left = left->next) { - if (e1->edge.top <= left->edge.bottom && - edges_colinear (e1, left)) - { - e1->deferred = left->deferred; - if (left->prev != NULL) - left->prev = left->next; - else - sweep_line.stopped = left->next; - if (left->next != NULL) - left->next->prev = left->prev; - break; - } - } - left = e1->prev; right = e1->next; @@ -1371,14 +1316,8 @@ _cairo_bentley_ottmann_tessellate_bo_edges (cairo_bo_event_t **start_events, _cairo_bo_sweep_line_delete (&sweep_line, e1); - /* first, check to see if we have a continuation via a fresh edge */ - if (e1->deferred.right != NULL) { - e1->next = sweep_line.stopped; - if (sweep_line.stopped != NULL) - sweep_line.stopped->prev = e1; - sweep_line.stopped = e1; - e1->prev = NULL; - } + if (e1->deferred.right != NULL) + _cairo_bo_edge_end (e1, e1->edge.bottom, polygon); if (left != NULL && right != NULL) { status = _cairo_bo_event_queue_insert_if_intersect_below_current_y (&event_queue, left, right); @@ -1420,10 +1359,6 @@ _cairo_bentley_ottmann_tessellate_bo_edges (cairo_bo_event_t **start_events, } } - for (e1 = sweep_line.stopped; e1; e1 = e1->next) { - if (e1->deferred.right != NULL) - _cairo_bo_edge_end (e1, e1->edge.bottom, polygon); - } unwind: _cairo_bo_event_queue_fini (&event_queue); @@ -1447,6 +1382,12 @@ _cairo_polygon_reduce (cairo_polygon_t *polygon, if (unlikely (0 == num_events)) return CAIRO_STATUS_SUCCESS; + if (DEBUG_POLYGON) { + FILE *file = fopen ("reduce_in.txt", "w"); + _cairo_debug_print_polygon (file, polygon); + fclose (file); + } + events = stack_events; event_ptrs = stack_event_ptrs; if (num_events > ARRAY_LENGTH (stack_events)) { @@ -1482,10 +1423,16 @@ _cairo_polygon_reduce (cairo_polygon_t *polygon, num_events, fill_rule, polygon); - polygon->num_limits = num_limits; + polygon->num_limits = num_limits; if (events != stack_events) free (events); + if (DEBUG_POLYGON) { + FILE *file = fopen ("reduce_out.txt", "w"); + _cairo_debug_print_polygon (file, polygon); + fclose (file); + } + return status; } -- cgit v0.9.0.2-2-gbebe