PIKApp/libpika/pikapattern.c

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2023-10-30 23:56:43 +01:00
/* LIBPIKA - The PIKA Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* pikapattern.c
* Copyright (C) 2023 Jehan
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "pika.h"
#include "pikapattern.h"
struct _PikaPattern
{
PikaResource parent_instance;
/* Native size buffer of the pattern contents. */
GeglBuffer *buffer;
};
static void pika_pattern_finalize (GObject *object);
static void pika_pattern_get_data (PikaPattern *pattern);
static GeglBuffer * pika_pattern_scale (GeglBuffer *buffer,
gint max_width,
gint max_height);
G_DEFINE_TYPE (PikaPattern, pika_pattern, PIKA_TYPE_RESOURCE);
static void pika_pattern_class_init (PikaPatternClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = pika_pattern_finalize;
}
static void pika_pattern_init (PikaPattern *pattern)
{
pattern->buffer = NULL;
}
static void
pika_pattern_finalize (GObject *object)
{
PikaPattern *pattern = PIKA_PATTERN (object);
g_clear_object (&pattern->buffer);
G_OBJECT_CLASS (pika_pattern_parent_class)->finalize (object);
}
/**
* pika_pattern_get_buffer:
* @pattern: a [class@Pattern].
* @max_width: a maximum width for the returned buffer.
* @max_height: a maximum height for the returned buffer.
* @format: an optional Babl format.
*
* Gets pixel data of the pattern within the bounding box specified by @max_width
* and @max_height. The data will be scaled down so that it fits within this
* size without changing its ratio. If the pattern is smaller than this size to
* begin with, it will not be scaled up.
*
* If @max_width or @max_height are %NULL, the buffer is returned in the pattern's
* native size.
*
* Make sure you called [func@Gegl.init] before calling any function using
* `GEGL`.
*
* Returns: (transfer full): a [class@Gegl.Buffer].
*/
GeglBuffer *
pika_pattern_get_buffer (PikaPattern *pattern,
gint max_width,
gint max_height,
const Babl *format)
{
pika_pattern_get_data (pattern);
g_return_val_if_fail (pattern->buffer != NULL, NULL);
if (max_width == 0 || max_height == 0 ||
(gegl_buffer_get_width (pattern->buffer) <= max_width &&
gegl_buffer_get_height (pattern->buffer) <= max_height))
return gegl_buffer_dup (pattern->buffer);
return pika_pattern_scale (pattern->buffer, max_width, max_height);
}
static void
pika_pattern_get_data (PikaPattern *pattern)
{
gint width;
gint height;
gint bpp;
GBytes *bytes;
const guchar *pixels;
gsize pixels_size;
const Babl *format;
/*
* This check assumes that the pattern contents doesn't change, which is not a
* perfect assumption. We could maybe add a PDB call which would return
* the new pattern data only if it changed since last call (which can be
* verified with some kind of internal runtime version to pass from one call
* to another). TODO
*/
if (pattern->buffer != NULL)
return;
g_clear_object (&pattern->buffer);
_pika_pattern_get_pixels (pattern, &width, &height, &bpp, &bytes);
pixels = g_bytes_unref_to_data (bytes, &pixels_size);
/* It's an ugly way to determine the proper format but pika_pattern_get_pixels()
* doesn't give more info.
*/
switch (bpp)
{
case 1:
format = babl_format ("Y' u8");
break;
case 2:
format = babl_format ("Y'A u8");
break;
case 3:
format = babl_format ("R'G'B' u8");
break;
case 4:
format = babl_format ("R'G'B'A u8");
break;
default:
g_return_if_reached ();
}
pattern->buffer = gegl_buffer_linear_new_from_data ((const gpointer) pixels, format,
GEGL_RECTANGLE (0, 0, width, height),
0, g_free, NULL);
}
static GeglBuffer *
pika_pattern_scale (GeglBuffer *buffer,
gint max_width,
gint max_height)
{
GeglBuffer *scaled = NULL;
GeglNode *graph;
GeglNode *source;
GeglNode *op;
GeglNode *sink;
gdouble width;
gdouble height;
gdouble scale;
height = (gdouble) max_height;
width = (gdouble) gegl_buffer_get_width (buffer) / gegl_buffer_get_height (buffer) * height;
if (width > (gdouble) max_width)
{
width = (gdouble) max_width;
height = (gdouble) gegl_buffer_get_height (buffer) / gegl_buffer_get_width (buffer) * width;
}
scale = width / gegl_buffer_get_width (buffer);
graph = gegl_node_new ();
source = gegl_node_new_child (graph,
"operation", "gegl:buffer-source",
"buffer", buffer,
NULL);
op = gegl_node_new_child (graph,
"operation", "gegl:scale-ratio",
"origin-x", 0.0,
"origin-y", 0.0,
"sampler", PIKA_INTERPOLATION_LINEAR,
"abyss-policy", GEGL_ABYSS_CLAMP,
"x", scale,
"y", scale,
NULL);
sink = gegl_node_new_child (graph,
"operation", "gegl:buffer-sink",
"buffer", &scaled,
"format", gegl_buffer_get_format (buffer),
NULL);
gegl_node_link_many (source, op, sink, NULL);
gegl_node_process (sink);
g_object_unref (graph);
return scaled;
}