Commit ba9ce34e authored by Ell's avatar Ell

app: add GimpChunkIterator

Factor out the region-chunking logic of GimpProjection into a new
GimpChunkIterator type, providing a generic mechanism for iterating
over a cairo region in discrete chunks.  The iterator doesn't
perform any processing itself, but rather dispenses rectangular
chunks, which the user then processes.

Iteration is broken into intervals, the duration of which is
configurable.  Each iteration begins with a call to
gimp_chunk_iterator_next(), after which
gimp_chunk_iterator_get_rect() should be called in succession to
fetch a rectangle to process, until it returns FALSE, which marks
the end of the iteration.  Updates to the UI should take place in
the interval between iterations, but not during an iteration.  The
iterator dynamically adjusts the chunk size according to processing
speed, in order to match the target iteration interval.

The iterator can be given a priority rectangle, which is processed
before the rest of the region.  It can also be given a
representative tile rectangle, defining a regular tile grid;
dispensed chunks are aligned to the tile grid as much as possible.
parent 005bc140
......@@ -143,6 +143,8 @@ libappcore_a_sources = \
gimpchannelpropundo.h \
gimpchannelundo.c \
gimpchannelundo.h \
gimpchunkiterator.c \
gimpchunkiterator.h \
gimpcontainer.c \
gimpcontainer.h \
gimpcontainer-filter.c \
......
......@@ -223,6 +223,7 @@ typedef struct _GimpWaitable GimpWaitable; /* dummy typede
typedef struct _GimpBacktrace GimpBacktrace;
typedef struct _GimpBoundSeg GimpBoundSeg;
typedef struct _GimpChunkIterator GimpChunkIterator;
typedef struct _GimpCoords GimpCoords;
typedef struct _GimpGradientSegment GimpGradientSegment;
typedef struct _GimpPaletteEntry GimpPaletteEntry;
......
/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995-1999 Spencer Kimball and Peter Mattis
*
* gimpchunkiterator.c
* Copyright (C) 2019 Ell
*
* 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 <cairo.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>
#include "libgimpmath/gimpmath.h"
#include "core-types.h"
#include "gimpchunkiterator.h"
/* the maximal chunk size */
#define MAX_CHUNK_WIDTH 4096
#define MAX_CHUNK_HEIGHT 4096
/* the default iteration interval */
#define DEFAULT_INTERVAL (1.0 / 15.0) /* seconds */
/* the minimal processed area on the current iteration, above which we
* calculate a new target area to render on the next iteration
*/
#define MIN_AREA_PER_UPDATE 1024
/* the width of the target-area sliding window */
#define TARGET_AREA_HISTORY_SIZE 5
struct _GimpChunkIterator
{
cairo_region_t *region;
cairo_region_t *priority_region;
GeglRectangle tile_rect;
GeglRectangle priority_rect;
gdouble interval;
cairo_region_t *current_region;
GeglRectangle current_rect;
gint current_x;
gint current_y;
gint current_height;
gint64 iteration_time;
gdouble current_area;
gdouble target_area;
gdouble target_area_history[TARGET_AREA_HISTORY_SIZE];
gint target_area_history_i;
};
/* local function prototypes */
static void gimp_chunk_iterator_set_current_rect (GimpChunkIterator *iter,
const GeglRectangle *rect);
static void gimp_chunk_iterator_merge_current_rect (GimpChunkIterator *iter);
static void gimp_chunk_iterator_merge (GimpChunkIterator *iter);
static gboolean gimp_chunk_iterator_prepare (GimpChunkIterator *iter);
/* private functions */
static void
gimp_chunk_iterator_set_current_rect (GimpChunkIterator *iter,
const GeglRectangle *rect)
{
cairo_region_subtract_rectangle (iter->current_region,
(const cairo_rectangle_int_t *) rect);
iter->current_rect = *rect;
iter->current_x = rect->x;
iter->current_y = rect->y;
}
static void
gimp_chunk_iterator_merge_current_rect (GimpChunkIterator *iter)
{
GeglRectangle rect;
gint current_height = 0;
if (gegl_rectangle_is_empty (&iter->current_rect))
return;
/* merge the remainder of the current row */
if (iter->current_x != iter->current_rect.x)
{
current_height = iter->current_height;
rect.x = iter->current_x;
rect.y = iter->current_y;
rect.width = iter->current_rect.x + iter->current_rect.width -
iter->current_x;
rect.height = current_height;
cairo_region_union_rectangle (iter->current_region,
(const cairo_rectangle_int_t *) &rect);
}
/* merge the remainder of the current rect */
rect.x = iter->current_rect.x;
rect.y = iter->current_y + current_height;
rect.width = iter->current_rect.width;
rect.height = iter->current_rect.y + iter->current_rect.height - rect.y;
cairo_region_union_rectangle (iter->current_region,
(const cairo_rectangle_int_t *) &rect);
/* reset the current rect and coordinates */
iter->current_rect.x = 0;
iter->current_rect.y = 0;
iter->current_rect.width = 0;
iter->current_rect.height = 0;
iter->current_x = 0;
iter->current_y = 0;
}
static void
gimp_chunk_iterator_merge (GimpChunkIterator *iter)
{
/* merge the current rect back to the current region */
gimp_chunk_iterator_merge_current_rect (iter);
/* merge the priority region back to the global region */
if (iter->priority_region)
{
cairo_region_union (iter->region, iter->priority_region);
g_clear_pointer (&iter->priority_region, cairo_region_destroy);
}
}
static gboolean
gimp_chunk_iterator_prepare (GimpChunkIterator *iter)
{
if (iter->current_x >= iter->current_rect.x + iter->current_rect.width)
{
iter->current_x = iter->current_rect.x;
iter->current_y += iter->current_height;
if (iter->current_y >= iter->current_rect.y + iter->current_rect.height)
{
GeglRectangle rect;
if (! iter->priority_region &&
! gegl_rectangle_is_empty (&iter->priority_rect))
{
iter->priority_region = cairo_region_copy (iter->region);
cairo_region_intersect_rectangle (
iter->priority_region,
(const cairo_rectangle_int_t *) &iter->priority_rect);
cairo_region_subtract_rectangle (
iter->region,
(const cairo_rectangle_int_t *) &iter->priority_rect);
}
if (! iter->priority_region ||
cairo_region_is_empty (iter->priority_region))
{
iter->current_region = iter->region;
}
else
{
iter->current_region = iter->priority_region;
}
if (cairo_region_is_empty (iter->current_region))
{
iter->current_rect.x = 0;
iter->current_rect.y = 0;
iter->current_rect.width = 0;
iter->current_rect.height = 0;
iter->current_x = 0;
iter->current_y = 0;
return FALSE;
}
cairo_region_get_rectangle (iter->current_region, 0,
(cairo_rectangle_int_t *) &rect);
gimp_chunk_iterator_set_current_rect (iter, &rect);
}
}
return TRUE;
}
/* public functions */
GimpChunkIterator *
gimp_chunk_iterator_new (cairo_region_t *region)
{
GimpChunkIterator *iter;
g_return_val_if_fail (region != NULL, NULL);
iter = g_slice_new0 (GimpChunkIterator);
iter->region = region;
g_object_get (gegl_config (),
"tile-width", &iter->tile_rect.width,
"tile-height", &iter->tile_rect.height,
NULL);
iter->interval = DEFAULT_INTERVAL;
return iter;
}
void
gimp_chunk_iterator_set_tile_rect (GimpChunkIterator *iter,
const GeglRectangle *rect)
{
g_return_if_fail (iter != NULL);
g_return_if_fail (rect != NULL);
g_return_if_fail (! gegl_rectangle_is_empty (rect));
iter->tile_rect = *rect;
}
void
gimp_chunk_iterator_set_priority_rect (GimpChunkIterator *iter,
const GeglRectangle *rect)
{
const GeglRectangle empty_rect = {};
g_return_if_fail (iter != NULL);
if (! rect)
rect = &empty_rect;
if (! gegl_rectangle_equal (rect, &iter->priority_rect))
{
iter->priority_rect = *rect;
gimp_chunk_iterator_merge (iter);
}
}
void
gimp_chunk_iterator_set_interval (GimpChunkIterator *iter,
gdouble interval)
{
g_return_if_fail (iter != NULL);
interval = MAX (interval, 0.0);
if (interval != iter->interval)
{
if (iter->interval)
{
gdouble ratio = interval / iter->interval;
gint i;
iter->target_area *= ratio;
for (i = 0; i < TARGET_AREA_HISTORY_SIZE; i++)
iter->target_area_history[i] *= ratio;
}
iter->interval = interval;
}
}
gboolean
gimp_chunk_iterator_next (GimpChunkIterator *iter)
{
g_return_val_if_fail (iter != NULL, FALSE);
if (! gimp_chunk_iterator_prepare (iter))
{
gimp_chunk_iterator_stop (iter, TRUE);
return FALSE;
}
iter->iteration_time = g_get_monotonic_time ();
iter->current_area = 0;
return TRUE;
}
static gint
compare_double (const gdouble *x,
const gdouble *y)
{
return (*y < *x) - (*x < *y);
}
gboolean
gimp_chunk_iterator_get_rect (GimpChunkIterator *iter,
GeglRectangle *rect)
{
gdouble interval;
gdouble aspect_ratio;
gint offset_x;
gint offset_y;
g_return_val_if_fail (iter != NULL, FALSE);
g_return_val_if_fail (rect != NULL, FALSE);
if (! gimp_chunk_iterator_prepare (iter))
return FALSE;
interval = (gdouble) (g_get_monotonic_time () - iter->iteration_time) /
G_TIME_SPAN_SECOND;
if (iter->current_area > 0 && interval > iter->interval)
{
/* adjust the target area to be processed on the next iteration,
* according to the area processed during this iteration and the elapsed
* time, in order to match the desired interval.
*/
if (iter->current_area >= MIN_AREA_PER_UPDATE)
{
gdouble target_area_history[TARGET_AREA_HISTORY_SIZE];
iter->target_area_history[iter->target_area_history_i] =
iter->current_area * iter->interval / interval;
/* calculate the median target area of the last
* TARGET_AREA_HISTORY_SIZE iterations
*/
memcpy (target_area_history, iter->target_area_history,
sizeof (target_area_history));
qsort (target_area_history, TARGET_AREA_HISTORY_SIZE,
sizeof (gdouble), (gpointer) compare_double);
iter->target_area = target_area_history[TARGET_AREA_HISTORY_SIZE / 2];
iter->target_area_history_i++;
iter->target_area_history_i %= TARGET_AREA_HISTORY_SIZE;
}
return FALSE;
}
if (! iter->target_area)
{
gint i;
iter->target_area = iter->tile_rect.width * iter->tile_rect.height;
for (i = 0; i < TARGET_AREA_HISTORY_SIZE; i++)
iter->target_area_history[i] = iter->target_area;
iter->target_area_history_i = 0;
}
aspect_ratio = (gdouble) iter->tile_rect.width /
(gdouble) iter->tile_rect.height;
rect->x = iter->current_x;
rect->y = iter->current_y;
offset_x = rect->x - iter->tile_rect.x;
offset_y = rect->y - iter->tile_rect.y;
rect->width = ceil ((offset_x + sqrt (iter->target_area * aspect_ratio)) /
iter->tile_rect.width) *
iter->tile_rect.width -
offset_x;
rect->height = ceil ((offset_y + (gdouble) iter->target_area /
(gdouble) rect->width) /
iter->tile_rect.height) *
iter->tile_rect.height -
offset_y;
rect->width = MIN (rect->width,
iter->current_rect.x + iter->current_rect.width -
rect->x);
rect->width = MIN (rect->width, MAX_CHUNK_WIDTH);
rect->height = MIN (rect->height,
iter->current_rect.y + iter->current_rect.height -
rect->y);
rect->height = MIN (rect->height, MAX_CHUNK_HEIGHT);
if (rect->height != iter->current_height)
{
/* if the chunk height changed in the middle of a row, merge the
* remaining area back into the current region, and reset the current
* area to the remainder of the row, using the new chunk height
*/
if (rect->x != iter->current_rect.x)
{
GeglRectangle rem;
rem.x = rect->x;
rem.y = rect->y;
rem.width = iter->current_rect.x + iter->current_rect.width -
rect->x;
rem.height = rect->height;
gimp_chunk_iterator_merge_current_rect (iter);
gimp_chunk_iterator_set_current_rect (iter, &rem);
}
iter->current_height = rect->height;
}
iter->current_x += rect->width;
iter->current_area += rect->width * rect->height;
return TRUE;
}
cairo_region_t *
gimp_chunk_iterator_stop (GimpChunkIterator *iter,
gboolean free_region)
{
cairo_region_t *result = NULL;
g_return_val_if_fail (iter != NULL, NULL);
if (free_region)
{
cairo_region_destroy (iter->region);
}
else
{
if (gimp_chunk_iterator_prepare (iter))
gimp_chunk_iterator_merge (iter);
result = iter->region;
}
g_clear_pointer (&iter->priority_region, cairo_region_destroy);
g_slice_free (GimpChunkIterator, iter);
return result;
}
/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimpchunkiterator.h
* Copyright (C) 2019 Ell
*
* 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/>.
*/
#ifndef __GIMP_CHUNK_ITEARTOR_H__
#define __GIMP_CHUNK_ITEARTOR_H__
GimpChunkIterator * gimp_chunk_iterator_new (cairo_region_t *region);
void gimp_chunk_iterator_set_tile_rect (GimpChunkIterator *iter,
const GeglRectangle *rect);
void gimp_chunk_iterator_set_priority_rect (GimpChunkIterator *iter,
const GeglRectangle *rect);
void gimp_chunk_iterator_set_interval (GimpChunkIterator *iter,
gdouble interval);
gboolean gimp_chunk_iterator_next (GimpChunkIterator *iter);
gboolean gimp_chunk_iterator_get_rect (GimpChunkIterator *iter,
GeglRectangle *rect);
cairo_region_t * gimp_chunk_iterator_stop (GimpChunkIterator *iter,
gboolean free_region);
#endif /* __GIMP_CHUNK_ITEARTOR_H__ */
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