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-mono-scan-converter.c | |
parent | 3dbe9332e47c143a237db12440f134caebd1cfbe (diff) |
add cairo
Diffstat (limited to 'libs/cairo-1.16.0/src/cairo-mono-scan-converter.c')
-rw-r--r-- | libs/cairo-1.16.0/src/cairo-mono-scan-converter.c | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/libs/cairo-1.16.0/src/cairo-mono-scan-converter.c b/libs/cairo-1.16.0/src/cairo-mono-scan-converter.c new file mode 100644 index 0000000..891f435 --- /dev/null +++ b/libs/cairo-1.16.0/src/cairo-mono-scan-converter.c @@ -0,0 +1,612 @@ +/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */ +/* + * Copyright (c) 2011 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ +#include "cairoint.h" +#include "cairo-spans-private.h" +#include "cairo-error-private.h" + +#include <stdlib.h> +#include <string.h> +#include <limits.h> + +struct quorem { + int32_t quo; + int32_t rem; +}; + +struct edge { + struct edge *next, *prev; + + int32_t height_left; + int32_t dir; + int32_t vertical; + + int32_t dy; + struct quorem x; + struct quorem dxdy; +}; + +/* A collection of sorted and vertically clipped edges of the polygon. + * Edges are moved from the polygon to an active list while scan + * converting. */ +struct polygon { + /* The vertical clip extents. */ + int32_t ymin, ymax; + + int num_edges; + struct edge *edges; + + /* Array of edges all starting in the same bucket. An edge is put + * into bucket EDGE_BUCKET_INDEX(edge->ytop, polygon->ymin) when + * it is added to the polygon. */ + struct edge **y_buckets; + + struct edge *y_buckets_embedded[64]; + struct edge edges_embedded[32]; +}; + +struct mono_scan_converter { + struct polygon polygon[1]; + + /* Leftmost edge on the current scan line. */ + struct edge head, tail; + int is_vertical; + + cairo_half_open_span_t *spans; + cairo_half_open_span_t spans_embedded[64]; + int num_spans; + + /* Clip box. */ + int32_t xmin, xmax; + int32_t ymin, ymax; +}; + +#define I(x) _cairo_fixed_integer_round_down(x) + +/* Compute the floored division a/b. Assumes / and % perform symmetric + * division. */ +inline static struct quorem +floored_divrem(int a, int b) +{ + struct quorem qr; + qr.quo = a/b; + qr.rem = a%b; + if ((a^b)<0 && qr.rem) { + qr.quo -= 1; + qr.rem += b; + } + return qr; +} + +/* Compute the floored division (x*a)/b. Assumes / and % perform symmetric + * division. */ +static struct quorem +floored_muldivrem(int x, int a, int b) +{ + struct quorem qr; + long long xa = (long long)x*a; + qr.quo = xa/b; + qr.rem = xa%b; + if ((xa>=0) != (b>=0) && qr.rem) { + qr.quo -= 1; + qr.rem += b; + } + return qr; +} + +static cairo_status_t +polygon_init (struct polygon *polygon, int ymin, int ymax) +{ + unsigned h = ymax - ymin + 1; + + polygon->y_buckets = polygon->y_buckets_embedded; + if (h > ARRAY_LENGTH (polygon->y_buckets_embedded)) { + polygon->y_buckets = _cairo_malloc_ab (h, sizeof (struct edge *)); + if (unlikely (NULL == polygon->y_buckets)) + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + } + memset (polygon->y_buckets, 0, h * sizeof (struct edge *)); + polygon->y_buckets[h-1] = (void *)-1; + + polygon->ymin = ymin; + polygon->ymax = ymax; + return CAIRO_STATUS_SUCCESS; +} + +static void +polygon_fini (struct polygon *polygon) +{ + if (polygon->y_buckets != polygon->y_buckets_embedded) + free (polygon->y_buckets); + + if (polygon->edges != polygon->edges_embedded) + free (polygon->edges); +} + +static void +_polygon_insert_edge_into_its_y_bucket(struct polygon *polygon, + struct edge *e, + int y) +{ + struct edge **ptail = &polygon->y_buckets[y - polygon->ymin]; + if (*ptail) + (*ptail)->prev = e; + e->next = *ptail; + e->prev = NULL; + *ptail = e; +} + +inline static void +polygon_add_edge (struct polygon *polygon, + const cairo_edge_t *edge) +{ + struct edge *e; + cairo_fixed_t dx; + cairo_fixed_t dy; + int y, ytop, ybot; + int ymin = polygon->ymin; + int ymax = polygon->ymax; + + y = I(edge->top); + ytop = MAX(y, ymin); + + y = I(edge->bottom); + ybot = MIN(y, ymax); + + if (ybot <= ytop) + return; + + e = polygon->edges + polygon->num_edges++; + e->height_left = ybot - ytop; + e->dir = edge->dir; + + dx = edge->line.p2.x - edge->line.p1.x; + dy = edge->line.p2.y - edge->line.p1.y; + + if (dx == 0) { + e->vertical = TRUE; + e->x.quo = edge->line.p1.x; + e->x.rem = 0; + e->dxdy.quo = 0; + e->dxdy.rem = 0; + e->dy = 0; + } else { + e->vertical = FALSE; + e->dxdy = floored_muldivrem (dx, CAIRO_FIXED_ONE, dy); + e->dy = dy; + + e->x = floored_muldivrem (ytop * CAIRO_FIXED_ONE + CAIRO_FIXED_FRAC_MASK/2 - edge->line.p1.y, + dx, dy); + e->x.quo += edge->line.p1.x; + } + e->x.rem -= dy; + + _polygon_insert_edge_into_its_y_bucket (polygon, e, ytop); +} + +static struct edge * +merge_sorted_edges (struct edge *head_a, struct edge *head_b) +{ + struct edge *head, **next, *prev; + int32_t x; + + prev = head_a->prev; + next = &head; + if (head_a->x.quo <= head_b->x.quo) { + head = head_a; + } else { + head = head_b; + head_b->prev = prev; + goto start_with_b; + } + + do { + x = head_b->x.quo; + while (head_a != NULL && head_a->x.quo <= x) { + prev = head_a; + next = &head_a->next; + head_a = head_a->next; + } + + head_b->prev = prev; + *next = head_b; + if (head_a == NULL) + return head; + +start_with_b: + x = head_a->x.quo; + while (head_b != NULL && head_b->x.quo <= x) { + prev = head_b; + next = &head_b->next; + head_b = head_b->next; + } + + head_a->prev = prev; + *next = head_a; + if (head_b == NULL) + return head; + } while (1); +} + +static struct edge * +sort_edges (struct edge *list, + unsigned int level, + struct edge **head_out) +{ + struct edge *head_other, *remaining; + unsigned int i; + + head_other = list->next; + + if (head_other == NULL) { + *head_out = list; + return NULL; + } + + remaining = head_other->next; + if (list->x.quo <= head_other->x.quo) { + *head_out = list; + head_other->next = NULL; + } else { + *head_out = head_other; + head_other->prev = list->prev; + head_other->next = list; + list->prev = head_other; + list->next = NULL; + } + + for (i = 0; i < level && remaining; i++) { + remaining = sort_edges (remaining, i, &head_other); + *head_out = merge_sorted_edges (*head_out, head_other); + } + + return remaining; +} + +static struct edge * +merge_unsorted_edges (struct edge *head, struct edge *unsorted) +{ + sort_edges (unsorted, UINT_MAX, &unsorted); + return merge_sorted_edges (head, unsorted); +} + +inline static void +active_list_merge_edges (struct mono_scan_converter *c, struct edge *edges) +{ + struct edge *e; + + for (e = edges; c->is_vertical && e; e = e->next) + c->is_vertical = e->vertical; + + c->head.next = merge_unsorted_edges (c->head.next, edges); +} + +inline static void +add_span (struct mono_scan_converter *c, int x1, int x2) +{ + int n; + + if (x1 < c->xmin) + x1 = c->xmin; + if (x2 > c->xmax) + x2 = c->xmax; + if (x2 <= x1) + return; + + n = c->num_spans++; + c->spans[n].x = x1; + c->spans[n].coverage = 255; + + n = c->num_spans++; + c->spans[n].x = x2; + c->spans[n].coverage = 0; +} + +inline static void +row (struct mono_scan_converter *c, unsigned int mask) +{ + struct edge *edge = c->head.next; + int xstart = INT_MIN, prev_x = INT_MIN; + int winding = 0; + + c->num_spans = 0; + while (&c->tail != edge) { + struct edge *next = edge->next; + int xend = I(edge->x.quo); + + if (--edge->height_left) { + if (!edge->vertical) { + edge->x.quo += edge->dxdy.quo; + edge->x.rem += edge->dxdy.rem; + if (edge->x.rem >= 0) { + ++edge->x.quo; + edge->x.rem -= edge->dy; + } + } + + if (edge->x.quo < prev_x) { + struct edge *pos = edge->prev; + pos->next = next; + next->prev = pos; + do { + pos = pos->prev; + } while (edge->x.quo < pos->x.quo); + pos->next->prev = edge; + edge->next = pos->next; + edge->prev = pos; + pos->next = edge; + } else + prev_x = edge->x.quo; + } else { + edge->prev->next = next; + next->prev = edge->prev; + } + + winding += edge->dir; + if ((winding & mask) == 0) { + if (I(next->x.quo) > xend + 1) { + add_span (c, xstart, xend); + xstart = INT_MIN; + } + } else if (xstart == INT_MIN) + xstart = xend; + + edge = next; + } +} + +inline static void dec (struct edge *e, int h) +{ + e->height_left -= h; + if (e->height_left == 0) { + e->prev->next = e->next; + e->next->prev = e->prev; + } +} + +static cairo_status_t +_mono_scan_converter_init(struct mono_scan_converter *c, + int xmin, int ymin, + int xmax, int ymax) +{ + cairo_status_t status; + int max_num_spans; + + status = polygon_init (c->polygon, ymin, ymax); + if (unlikely (status)) + return status; + + max_num_spans = xmax - xmin + 1; + if (max_num_spans > ARRAY_LENGTH(c->spans_embedded)) { + c->spans = _cairo_malloc_ab (max_num_spans, + sizeof (cairo_half_open_span_t)); + if (unlikely (c->spans == NULL)) { + polygon_fini (c->polygon); + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + } + } else + c->spans = c->spans_embedded; + + c->xmin = xmin; + c->xmax = xmax; + c->ymin = ymin; + c->ymax = ymax; + + c->head.vertical = 1; + c->head.height_left = INT_MAX; + c->head.x.quo = _cairo_fixed_from_int (_cairo_fixed_integer_part (INT_MIN)); + c->head.prev = NULL; + c->head.next = &c->tail; + c->tail.prev = &c->head; + c->tail.next = NULL; + c->tail.x.quo = _cairo_fixed_from_int (_cairo_fixed_integer_part (INT_MAX)); + c->tail.height_left = INT_MAX; + c->tail.vertical = 1; + + c->is_vertical = 1; + return CAIRO_STATUS_SUCCESS; +} + +static void +_mono_scan_converter_fini(struct mono_scan_converter *self) +{ + if (self->spans != self->spans_embedded) + free (self->spans); + + polygon_fini(self->polygon); +} + +static cairo_status_t +mono_scan_converter_allocate_edges(struct mono_scan_converter *c, + int num_edges) + +{ + c->polygon->num_edges = 0; + c->polygon->edges = c->polygon->edges_embedded; + if (num_edges > ARRAY_LENGTH (c->polygon->edges_embedded)) { + c->polygon->edges = _cairo_malloc_ab (num_edges, sizeof (struct edge)); + if (unlikely (c->polygon->edges == NULL)) + return _cairo_error (CAIRO_STATUS_NO_MEMORY); + } + + return CAIRO_STATUS_SUCCESS; +} + +static void +mono_scan_converter_add_edge (struct mono_scan_converter *c, + const cairo_edge_t *edge) +{ + polygon_add_edge (c->polygon, edge); +} + +static void +step_edges (struct mono_scan_converter *c, int count) +{ + struct edge *edge; + + for (edge = c->head.next; edge != &c->tail; edge = edge->next) { + edge->height_left -= count; + if (! edge->height_left) { + edge->prev->next = edge->next; + edge->next->prev = edge->prev; + } + } +} + +static cairo_status_t +mono_scan_converter_render(struct mono_scan_converter *c, + unsigned int winding_mask, + cairo_span_renderer_t *renderer) +{ + struct polygon *polygon = c->polygon; + int i, j, h = c->ymax - c->ymin; + cairo_status_t status; + + for (i = 0; i < h; i = j) { + j = i + 1; + + if (polygon->y_buckets[i]) + active_list_merge_edges (c, polygon->y_buckets[i]); + + if (c->is_vertical) { + int min_height; + struct edge *e; + + e = c->head.next; + min_height = e->height_left; + while (e != &c->tail) { + if (e->height_left < min_height) + min_height = e->height_left; + e = e->next; + } + + while (--min_height >= 1 && polygon->y_buckets[j] == NULL) + j++; + if (j != i + 1) + step_edges (c, j - (i + 1)); + } + + row (c, winding_mask); + if (c->num_spans) { + status = renderer->render_rows (renderer, c->ymin+i, j-i, + c->spans, c->num_spans); + if (unlikely (status)) + return status; + } + + /* XXX recompute after dropping edges? */ + if (c->head.next == &c->tail) + c->is_vertical = 1; + } + + return CAIRO_STATUS_SUCCESS; +} + +struct _cairo_mono_scan_converter { + cairo_scan_converter_t base; + + struct mono_scan_converter converter[1]; + cairo_fill_rule_t fill_rule; +}; + +typedef struct _cairo_mono_scan_converter cairo_mono_scan_converter_t; + +static void +_cairo_mono_scan_converter_destroy (void *converter) +{ + cairo_mono_scan_converter_t *self = converter; + _mono_scan_converter_fini (self->converter); + free(self); +} + +cairo_status_t +_cairo_mono_scan_converter_add_polygon (void *converter, + const cairo_polygon_t *polygon) +{ + cairo_mono_scan_converter_t *self = converter; + cairo_status_t status; + int i; + +#if 0 + FILE *file = fopen ("polygon.txt", "w"); + _cairo_debug_print_polygon (file, polygon); + fclose (file); +#endif + + status = mono_scan_converter_allocate_edges (self->converter, + polygon->num_edges); + if (unlikely (status)) + return status; + + for (i = 0; i < polygon->num_edges; i++) + mono_scan_converter_add_edge (self->converter, &polygon->edges[i]); + + return CAIRO_STATUS_SUCCESS; +} + +static cairo_status_t +_cairo_mono_scan_converter_generate (void *converter, + cairo_span_renderer_t *renderer) +{ + cairo_mono_scan_converter_t *self = converter; + + return mono_scan_converter_render (self->converter, + self->fill_rule == CAIRO_FILL_RULE_WINDING ? ~0 : 1, + renderer); +} + +cairo_scan_converter_t * +_cairo_mono_scan_converter_create (int xmin, + int ymin, + int xmax, + int ymax, + cairo_fill_rule_t fill_rule) +{ + cairo_mono_scan_converter_t *self; + cairo_status_t status; + + self = _cairo_malloc (sizeof(struct _cairo_mono_scan_converter)); + if (unlikely (self == NULL)) { + status = _cairo_error (CAIRO_STATUS_NO_MEMORY); + goto bail_nomem; + } + + self->base.destroy = _cairo_mono_scan_converter_destroy; + self->base.generate = _cairo_mono_scan_converter_generate; + + status = _mono_scan_converter_init (self->converter, + xmin, ymin, xmax, ymax); + if (unlikely (status)) + goto bail; + + self->fill_rule = fill_rule; + + return &self->base; + + bail: + self->base.destroy(&self->base); + bail_nomem: + return _cairo_scan_converter_create_in_error (status); +} |