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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:30:19 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:30:19 +0000 |
commit | 5c1676dfe6d2f3c837a5e074117b45613fd29a72 (patch) | |
tree | cbffb45144febf451e54061db2b21395faf94bfe /app/core/gimppickable-contiguous-region.cc | |
parent | Initial commit. (diff) | |
download | gimp-5c1676dfe6d2f3c837a5e074117b45613fd29a72.tar.xz gimp-5c1676dfe6d2f3c837a5e074117b45613fd29a72.zip |
Adding upstream version 2.10.34.upstream/2.10.34upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | app/core/gimppickable-contiguous-region.cc | 1123 |
1 files changed, 1123 insertions, 0 deletions
diff --git a/app/core/gimppickable-contiguous-region.cc b/app/core/gimppickable-contiguous-region.cc new file mode 100644 index 0000000..ea30d0c --- /dev/null +++ b/app/core/gimppickable-contiguous-region.cc @@ -0,0 +1,1123 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include <stdlib.h> + +#include <cairo.h> +#include <gegl.h> +#include <gdk-pixbuf/gdk-pixbuf.h> + +#include "libgimpcolor/gimpcolor.h" +#include "libgimpmath/gimpmath.h" + +extern "C" +{ + +#include "core-types.h" + +#include "gegl/gimp-babl.h" + +#include "gimp-parallel.h" +#include "gimp-utils.h" /* GIMP_TIMER */ +#include "gimpasync.h" +#include "gimplineart.h" +#include "gimppickable.h" +#include "gimppickable-contiguous-region.h" + + +#define EPSILON 1e-6 + +#define PIXELS_PER_THREAD \ + (/* each thread costs as much as */ 64.0 * 64.0 /* pixels */) + + +typedef struct +{ + gint x; + gint y; + gint level; +} BorderPixel; + + +/* local function prototypes */ + +static const Babl * choose_format (GeglBuffer *buffer, + GimpSelectCriterion select_criterion, + gint *n_components, + gboolean *has_alpha); +static gfloat pixel_difference (const gfloat *col1, + const gfloat *col2, + gboolean antialias, + gfloat threshold, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion); +static void push_segment (GQueue *segment_queue, + gint y, + gint old_y, + gint start, + gint end, + gint new_y, + gint new_start, + gint new_end); +static void pop_segment (GQueue *segment_queue, + gint *y, + gint *old_y, + gint *start, + gint *end); +static gboolean find_contiguous_segment (const gfloat *col, + GeglBuffer *src_buffer, + GeglSampler *src_sampler, + const GeglRectangle *src_extent, + GeglBuffer *mask_buffer, + const Babl *src_format, + const Babl *mask_format, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + gboolean antialias, + gfloat threshold, + gint initial_x, + gint initial_y, + gint *start, + gint *end, + gfloat *row); +static void find_contiguous_region (GeglBuffer *src_buffer, + GeglBuffer *mask_buffer, + const Babl *format, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + gboolean antialias, + gfloat threshold, + gboolean diagonal_neighbors, + gint x, + gint y, + const gfloat *col); + +static void line_art_queue_pixel (GQueue *queue, + gint x, + gint y, + gint level); + + +/* public functions */ + +GeglBuffer * +gimp_pickable_contiguous_region_by_seed (GimpPickable *pickable, + gboolean antialias, + gfloat threshold, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + gboolean diagonal_neighbors, + gint x, + gint y) +{ + GeglBuffer *src_buffer; + GeglBuffer *mask_buffer; + const Babl *format; + GeglRectangle extent; + gint n_components; + gboolean has_alpha; + gfloat start_col[MAX_CHANNELS]; + + g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), NULL); + + gimp_pickable_flush (pickable); + src_buffer = gimp_pickable_get_buffer (pickable); + + format = choose_format (src_buffer, select_criterion, + &n_components, &has_alpha); + gegl_buffer_sample (src_buffer, x, y, NULL, start_col, format, + GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE); + + if (has_alpha) + { + if (select_transparent) + { + /* don't select transparent regions if the start pixel isn't + * fully transparent + */ + if (start_col[n_components - 1] > 0) + select_transparent = FALSE; + } + } + else + { + select_transparent = FALSE; + } + + extent = *gegl_buffer_get_extent (src_buffer); + + mask_buffer = gegl_buffer_new (&extent, babl_format ("Y float")); + + if (x >= extent.x && x < (extent.x + extent.width) && + y >= extent.y && y < (extent.y + extent.height)) + { + GIMP_TIMER_START(); + + find_contiguous_region (src_buffer, mask_buffer, + format, n_components, has_alpha, + select_transparent, select_criterion, + antialias, threshold, diagonal_neighbors, + x, y, start_col); + + GIMP_TIMER_END("foo"); + } + + return mask_buffer; +} + +GeglBuffer * +gimp_pickable_contiguous_region_by_color (GimpPickable *pickable, + gboolean antialias, + gfloat threshold, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + const GimpRGB *color) +{ + /* Scan over the pickable's active layer, finding pixels within the + * specified threshold from the given R, G, & B values. If + * antialiasing is on, use the same antialiasing scheme as in + * fuzzy_select. Modify the pickable's mask to reflect the + * additional selection + */ + GeglBuffer *src_buffer; + GeglBuffer *mask_buffer; + const Babl *format; + gint n_components; + gboolean has_alpha; + gfloat start_col[MAX_CHANNELS]; + + g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), NULL); + g_return_val_if_fail (color != NULL, NULL); + + /* increase the threshold by EPSILON, to allow for conversion errors, + * especially when threshold == 0 (see issue #1554.) we need to do this + * here, but not in the other functions, since the input color gets converted + * to the format in which we perform the comparison through a different path + * than the pickable's pixels, which can introduce error. + */ + threshold += EPSILON; + + gimp_pickable_flush (pickable); + + src_buffer = gimp_pickable_get_buffer (pickable); + + format = choose_format (src_buffer, select_criterion, + &n_components, &has_alpha); + + gimp_rgba_get_pixel (color, format, start_col); + + if (has_alpha) + { + if (select_transparent) + { + /* don't select transparency if "color" isn't fully transparent + */ + if (start_col[n_components - 1] > 0.0) + select_transparent = FALSE; + } + } + else + { + select_transparent = FALSE; + } + + mask_buffer = gegl_buffer_new (gegl_buffer_get_extent (src_buffer), + babl_format ("Y float")); + + gegl_parallel_distribute_area ( + gegl_buffer_get_extent (src_buffer), PIXELS_PER_THREAD, + [=] (const GeglRectangle *area) + { + GeglBufferIterator *iter; + + iter = gegl_buffer_iterator_new (src_buffer, + area, 0, format, + GEGL_ACCESS_READ, GEGL_ABYSS_NONE, 2); + + gegl_buffer_iterator_add (iter, mask_buffer, + area, 0, babl_format ("Y float"), + GEGL_ACCESS_WRITE, GEGL_ABYSS_NONE); + + while (gegl_buffer_iterator_next (iter)) + { + const gfloat *src = (const gfloat *) iter->items[0].data; + gfloat *dest = ( gfloat *) iter->items[1].data; + gint count = iter->length; + + while (count--) + { + /* Find how closely the colors match */ + *dest = pixel_difference (start_col, src, + antialias, + threshold, + n_components, + has_alpha, + select_transparent, + select_criterion); + + src += n_components; + dest += 1; + } + } + }); + + return mask_buffer; +} + +GeglBuffer * +gimp_pickable_contiguous_region_by_line_art (GimpPickable *pickable, + GimpLineArt *line_art, + gint x, + gint y) +{ + GeglBuffer *src_buffer; + GeglBuffer *mask_buffer; + const Babl *format = babl_format ("Y float"); + gfloat *distmap = NULL; + GeglRectangle extent; + gboolean free_line_art = FALSE; + gboolean filled = FALSE; + guchar start_col; + + g_return_val_if_fail (GIMP_IS_PICKABLE (pickable) || GIMP_IS_LINE_ART (line_art), NULL); + + if (! line_art) + { + /* It is much better experience to pre-compute the line art, + * but it may not be always possible (for instance when + * selecting/filling through a PDB call). + */ + line_art = gimp_line_art_new (); + gimp_line_art_set_input (line_art, pickable); + free_line_art = TRUE; + } + + src_buffer = gimp_line_art_get (line_art, &distmap); + g_return_val_if_fail (src_buffer && distmap, NULL); + + gegl_buffer_sample (src_buffer, x, y, NULL, &start_col, NULL, + GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE); + + extent = *gegl_buffer_get_extent (src_buffer); + + mask_buffer = gegl_buffer_new (&extent, format); + + if (start_col) + { + if (start_col == 1) + { + /* As a special exception, if you fill over a line art pixel, only + * fill the pixel and exit + */ + gfloat col = 1.0; + + gegl_buffer_set (mask_buffer, GEGL_RECTANGLE (x, y, 1, 1), + 0, format, &col, GEGL_AUTO_ROWSTRIDE); + } + else /* start_col == 2 */ + { + /* If you fill over a closure pixel, let's fill on all sides + * of the start point. Otherwise we get a very weird result + * with only a single pixel filled in the middle of an empty + * region (since closure pixels are invisible by nature). + */ + gfloat col = 0.0; + + if (x - 1 >= extent.x && x - 1 < extent.x + extent.width && + y - 1 >= extent.y && y - 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x - 1, y - 1, &col); + if (x - 1 >= extent.x && x - 1 < extent.x + extent.width && + y >= extent.y && y < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x - 1, y, &col); + if (x - 1 >= extent.x && x - 1 < extent.x + extent.width && + y + 1 >= extent.y && y + 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x - 1, y + 1, &col); + if (x >= extent.x && x < extent.x + extent.width && + y - 1 >= extent.y && y - 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x, y - 1, &col); + if (x >= extent.x && x < extent.x + extent.width && + y + 1 >= extent.y && y + 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x, y + 1, &col); + if (x + 1 >= extent.x && x + 1 < extent.x + extent.width && + y - 1 >= extent.y && y - 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x + 1, y - 1, &col); + if (x + 1 >= extent.x && x + 1 < extent.x + extent.width && + y >= extent.y && y < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x + 1, y, &col); + if (x + 1 >= extent.x && x + 1 < extent.x + extent.width && + y + 1 >= extent.y && y + 1 < (extent.y + extent.height)) + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x + 1, y + 1, &col); + filled = TRUE; + } + } + else if (x >= extent.x && x < (extent.x + extent.width) && + y >= extent.y && y < (extent.y + extent.height)) + { + gfloat col = 0.0; + + find_contiguous_region (src_buffer, mask_buffer, + format, 1, FALSE, + FALSE, GIMP_SELECT_CRITERION_COMPOSITE, + FALSE, 0.0, FALSE, + x, y, &col); + filled = TRUE; + } + + if (filled) + { + GQueue *queue = g_queue_new (); + gfloat *mask; + gint width = gegl_buffer_get_width (src_buffer); + gint height = gegl_buffer_get_height (src_buffer); + gint line_art_max_grow; + gint nx, ny; + + GIMP_TIMER_START(); + /* The last step of the line art algorithm is to make sure that + * selections does not leave "holes" between its borders and the + * line arts, while not stepping over as well. + * I used to run the "gegl:watershed-transform" operation to flood + * the stroke pixels, but for such simple need, this simple code + * is so much faster while producing better results. + */ + mask = g_new (gfloat, width * height); + gegl_buffer_get (mask_buffer, NULL, 1.0, NULL, + mask, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE); + + for (y = 0; y < height; y++) + for (x = 0; x < width; x++) + { + if (distmap[x + y * width] == 1.0) + { + if (x > 0) + { + nx = x - 1; + if (y > 0) + { + ny = y - 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + ny = y; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + if (y < height - 1) + { + ny = y + 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + } + if (x < width - 1) + { + nx = x + 1; + if (y > 0) + { + ny = y - 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + ny = y; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + if (y < height - 1) + { + ny = y + 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + } + nx = x; + if (y > 0) + { + ny = y - 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + if (y < height - 1) + { + ny = y + 1; + if (mask[nx + ny * width] != 0.0) + { + line_art_queue_pixel (queue, x, y, 1); + continue; + } + } + } + } + + g_object_get (line_art, + "max-grow", &line_art_max_grow, + NULL); + while (! g_queue_is_empty (queue)) + { + BorderPixel *c = (BorderPixel *) g_queue_pop_head (queue); + + if (mask[c->x + c->y * width] != 1.0) + { + mask[c->x + c->y * width] = 1.0; + if (c->level >= line_art_max_grow) + /* Do not overflood under line arts. */ + continue; + if (c->x > 0) + { + nx = c->x - 1; + if (c->y > 0) + { + ny = c->y - 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + ny = c->y; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + if (c->y < height - 1) + { + ny = c->y + 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + } + if (c->x < width - 1) + { + nx = c->x + 1; + if (c->y > 0) + { + ny = c->y - 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + ny = c->y; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + if (c->y < height - 1) + { + ny = c->y + 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + } + nx = c->x; + if (c->y > 0) + { + ny = c->y - 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + if (c->y < height - 1) + { + ny = c->y + 1; + if (mask[nx + ny * width] == 0.0 && + distmap[nx + ny * width] > distmap[c->x + c->y * width]) + line_art_queue_pixel (queue, nx, ny, c->level + 1); + } + } + g_free (c); + } + g_queue_free (queue); + gegl_buffer_set (mask_buffer, gegl_buffer_get_extent (mask_buffer), + 0, NULL, mask, GEGL_AUTO_ROWSTRIDE); + g_free (mask); + + GIMP_TIMER_END("watershed line art"); + } + if (free_line_art) + g_clear_object (&line_art); + + return mask_buffer; +} + +/* private functions */ + +static const Babl * +choose_format (GeglBuffer *buffer, + GimpSelectCriterion select_criterion, + gint *n_components, + gboolean *has_alpha) +{ + const Babl *format = gegl_buffer_get_format (buffer); + + *has_alpha = babl_format_has_alpha (format); + + switch (select_criterion) + { + case GIMP_SELECT_CRITERION_COMPOSITE: + if (babl_format_is_palette (format)) + format = babl_format ("R'G'B'A float"); + else + format = gimp_babl_format (gimp_babl_format_get_base_type (format), + GIMP_PRECISION_FLOAT_GAMMA, + *has_alpha); + break; + + case GIMP_SELECT_CRITERION_R: + case GIMP_SELECT_CRITERION_G: + case GIMP_SELECT_CRITERION_B: + case GIMP_SELECT_CRITERION_A: + format = babl_format ("R'G'B'A float"); + break; + + case GIMP_SELECT_CRITERION_H: + case GIMP_SELECT_CRITERION_S: + case GIMP_SELECT_CRITERION_V: + format = babl_format ("HSVA float"); + break; + + case GIMP_SELECT_CRITERION_LCH_L: + format = babl_format ("CIE L alpha float"); + break; + + case GIMP_SELECT_CRITERION_LCH_C: + case GIMP_SELECT_CRITERION_LCH_H: + format = babl_format ("CIE LCH(ab) alpha float"); + break; + + default: + g_return_val_if_reached (NULL); + break; + } + + *n_components = babl_format_get_n_components (format); + + return format; +} + +static gfloat +pixel_difference (const gfloat *col1, + const gfloat *col2, + gboolean antialias, + gfloat threshold, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion) +{ + gfloat max = 0.0; + + /* if there is an alpha channel, never select transparent regions */ + if (! select_transparent && has_alpha && col2[n_components - 1] == 0.0) + return 0.0; + + if (select_transparent && has_alpha) + { + max = fabs (col1[n_components - 1] - col2[n_components - 1]); + } + else + { + gfloat diff; + gint b; + + if (has_alpha) + n_components--; + + switch (select_criterion) + { + case GIMP_SELECT_CRITERION_COMPOSITE: + for (b = 0; b < n_components; b++) + { + diff = fabs (col1[b] - col2[b]); + if (diff > max) + max = diff; + } + break; + + case GIMP_SELECT_CRITERION_R: + max = fabs (col1[0] - col2[0]); + break; + + case GIMP_SELECT_CRITERION_G: + max = fabs (col1[1] - col2[1]); + break; + + case GIMP_SELECT_CRITERION_B: + max = fabs (col1[2] - col2[2]); + break; + + case GIMP_SELECT_CRITERION_A: + max = fabs (col1[3] - col2[3]); + break; + + case GIMP_SELECT_CRITERION_H: + if (col1[1] > EPSILON) + { + if (col2[1] > EPSILON) + { + max = fabs (col1[0] - col2[0]); + max = MIN (max, 1.0 - max); + } + else + { + /* "infinite" difference. anything >> 1 will do. */ + max = 10.0; + } + } + else + { + if (col2[1] > EPSILON) + { + /* "infinite" difference. anything >> 1 will do. */ + max = 10.0; + } + else + { + max = 0.0; + } + } + break; + + case GIMP_SELECT_CRITERION_S: + max = fabs (col1[1] - col2[1]); + break; + + case GIMP_SELECT_CRITERION_V: + max = fabs (col1[2] - col2[2]); + break; + + case GIMP_SELECT_CRITERION_LCH_L: + max = fabs (col1[0] - col2[0]) / 100.0; + break; + + case GIMP_SELECT_CRITERION_LCH_C: + max = fabs (col1[1] - col2[1]) / 100.0; + break; + + case GIMP_SELECT_CRITERION_LCH_H: + if (col1[1] > 100.0 * EPSILON) + { + if (col2[1] > 100.0 * EPSILON) + { + max = fabs (col1[2] - col2[2]) / 360.0; + max = MIN (max, 1.0 - max); + } + else + { + /* "infinite" difference. anything >> 1 will do. */ + max = 10.0; + } + } + else + { + if (col2[1] > 100.0 * EPSILON) + { + /* "infinite" difference. anything >> 1 will do. */ + max = 10.0; + } + else + { + max = 0.0; + } + } + break; + } + } + + if (antialias && threshold > 0.0) + { + gfloat aa = 1.5 - (max / threshold); + + if (aa <= 0.0) + return 0.0; + else if (aa < 0.5) + return aa * 2.0; + else + return 1.0; + } + else + { + if (max > threshold) + return 0.0; + else + return 1.0; + } +} + +static void +push_segment (GQueue *segment_queue, + gint y, + gint old_y, + gint start, + gint end, + gint new_y, + gint new_start, + gint new_end) +{ + /* To avoid excessive memory allocation (y, old_y, start, end) tuples are + * stored in interleaved format: + * + * [y1] [old_y1] [start1] [end1] [y2] [old_y2] [start2] [end2] + */ + + if (new_y != old_y) + { + /* If the new segment's y-coordinate is different than the old (source) + * segment's y-coordinate, push the entire segment. + */ + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_start)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_end)); + } + else + { + /* Otherwise, only push the set-difference between the new segment and + * the source segment (since we've already scanned the source segment.) + * Note that the `+ 1` and `- 1` terms of the end/start coordinates below + * are only necessary when `diagonal_neighbors` is on (and otherwise make + * the segments slightly larger than necessary), but, meh... + */ + if (new_start < start) + { + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_start)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (start + 1)); + } + + if (new_end > end) + { + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (y)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (end - 1)); + g_queue_push_tail (segment_queue, GINT_TO_POINTER (new_end)); + } + } +} + +static void +pop_segment (GQueue *segment_queue, + gint *y, + gint *old_y, + gint *start, + gint *end) +{ + *y = GPOINTER_TO_INT (g_queue_pop_head (segment_queue)); + *old_y = GPOINTER_TO_INT (g_queue_pop_head (segment_queue)); + *start = GPOINTER_TO_INT (g_queue_pop_head (segment_queue)); + *end = GPOINTER_TO_INT (g_queue_pop_head (segment_queue)); +} + +/* #define FETCH_ROW 1 */ + +static gboolean +find_contiguous_segment (const gfloat *col, + GeglBuffer *src_buffer, + GeglSampler *src_sampler, + const GeglRectangle *src_extent, + GeglBuffer *mask_buffer, + const Babl *src_format, + const Babl *mask_format, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + gboolean antialias, + gfloat threshold, + gint initial_x, + gint initial_y, + gint *start, + gint *end, + gfloat *row) +{ + gfloat *s; + gfloat mask_row_buf[src_extent->width]; + gfloat *mask_row = mask_row_buf - src_extent->x; + gfloat diff; + +#ifdef FETCH_ROW + gegl_buffer_get (src_buffer, GEGL_RECTANGLE (0, initial_y, width, 1), 1.0, + src_format, + row, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE); + s = row + initial_x * n_components; +#else + s = (gfloat *) g_alloca (n_components * sizeof (gfloat)); + + gegl_sampler_get (src_sampler, + initial_x, initial_y, NULL, s, GEGL_ABYSS_NONE); +#endif + + diff = pixel_difference (col, s, antialias, threshold, + n_components, has_alpha, select_transparent, + select_criterion); + + /* check the starting pixel */ + if (! diff) + return FALSE; + + mask_row[initial_x] = diff; + + *start = initial_x - 1; +#ifdef FETCH_ROW + s = row + *start * n_components; +#endif + + while (*start >= src_extent->x) + { +#ifndef FETCH_ROW + gegl_sampler_get (src_sampler, + *start, initial_y, NULL, s, GEGL_ABYSS_NONE); +#endif + + diff = pixel_difference (col, s, antialias, threshold, + n_components, has_alpha, select_transparent, + select_criterion); + if (diff == 0.0) + break; + + mask_row[*start] = diff; + + (*start)--; +#ifdef FETCH_ROW + s -= n_components; +#endif + } + + *end = initial_x + 1; +#ifdef FETCH_ROW + s = row + *end * n_components; +#endif + + while (*end < src_extent->x + src_extent->width) + { +#ifndef FETCH_ROW + gegl_sampler_get (src_sampler, + *end, initial_y, NULL, s, GEGL_ABYSS_NONE); +#endif + + diff = pixel_difference (col, s, antialias, threshold, + n_components, has_alpha, select_transparent, + select_criterion); + if (diff == 0.0) + break; + + mask_row[*end] = diff; + + (*end)++; +#ifdef FETCH_ROW + s += n_components; +#endif + } + + gegl_buffer_set (mask_buffer, GEGL_RECTANGLE (*start + 1, initial_y, + *end - *start - 1, 1), + 0, mask_format, &mask_row[*start + 1], + GEGL_AUTO_ROWSTRIDE); + + return TRUE; +} + +static void +find_contiguous_region (GeglBuffer *src_buffer, + GeglBuffer *mask_buffer, + const Babl *format, + gint n_components, + gboolean has_alpha, + gboolean select_transparent, + GimpSelectCriterion select_criterion, + gboolean antialias, + gfloat threshold, + gboolean diagonal_neighbors, + gint x, + gint y, + const gfloat *col) +{ + const Babl *mask_format = babl_format ("Y float"); + GeglSampler *src_sampler; + const GeglRectangle *src_extent; + gint old_y; + gint start, end; + gint new_start, new_end; + GQueue *segment_queue; + gfloat *row = NULL; + + src_extent = gegl_buffer_get_extent (src_buffer); + +#ifdef FETCH_ROW + row = g_new (gfloat, src_extent->width * n_components); +#endif + + src_sampler = gegl_buffer_sampler_new (src_buffer, + format, GEGL_SAMPLER_NEAREST); + + segment_queue = g_queue_new (); + + push_segment (segment_queue, + y, /* dummy values: */ -1, 0, 0, + y, x - 1, x + 1); + + do + { + pop_segment (segment_queue, + &y, &old_y, &start, &end); + + for (x = start + 1; x < end; x++) + { + gfloat val; + + gegl_buffer_get (mask_buffer, GEGL_RECTANGLE (x, y, 1, 1), 1.0, + mask_format, &val, GEGL_AUTO_ROWSTRIDE, + GEGL_ABYSS_NONE); + + if (val != 0.0) + { + /* If the current pixel is selected, then we've already visited + * the next pixel. (Note that we assume that the maximal image + * width is sufficiently low that `x` won't overflow.) + */ + x++; + continue; + } + + if (! find_contiguous_segment (col, + src_buffer, src_sampler, src_extent, + mask_buffer, + format, mask_format, + n_components, + has_alpha, + select_transparent, select_criterion, + antialias, threshold, x, y, + &new_start, &new_end, + row)) + continue; + + /* We can skip directly to `new_end + 1` on the next iteration, since + * we've just selected all pixels in the range `[x, new_end)`, and + * the pixel at `new_end` is above threshold. (Note that we assume + * that the maximal image width is sufficiently low that `x` won't + * overflow.) + */ + x = new_end; + + if (diagonal_neighbors) + { + if (new_start >= src_extent->x) + new_start--; + + if (new_end < src_extent->x + src_extent->width) + new_end++; + } + + if (y + 1 < src_extent->y + src_extent->height) + { + push_segment (segment_queue, + y, old_y, start, end, + y + 1, new_start, new_end); + } + + if (y - 1 >= src_extent->y) + { + push_segment (segment_queue, + y, old_y, start, end, + y - 1, new_start, new_end); + } + + } + } + while (! g_queue_is_empty (segment_queue)); + + g_queue_free (segment_queue); + + g_object_unref (src_sampler); + +#ifdef FETCH_ROW + g_free (row); +#endif +} + +static void +line_art_queue_pixel (GQueue *queue, + gint x, + gint y, + gint level) +{ + BorderPixel *p = g_new (BorderPixel, 1); + + p->x = x; + p->y = y; + p->level = level; + + g_queue_push_head (queue, p); +} + +} /* extern "C" */ |