[gegl] workshop: reimplment hstack as pack

[Øyvind "pippin" Kolås <ok src gnome org>]

commit d90c17a3f8178e3dfcff32c5fe819fd90f75f850
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue May 19 21:00:14 2020 +0200

    workshop: reimplment hstack as pack
    
    An op to put two buffers next to each other, with an optional gap.

 operations/workshop/hstack.c    | 190 ----------------------------------------
 operations/workshop/meson.build |   2 +-
 operations/workshop/pack.c      | 140 +++++++++++++++++++++++++++++
 po/POTFILES.in                  |   2 +-
 4 files changed, 142 insertions(+), 192 deletions(-)
---
diff --git a/operations/workshop/meson.build b/operations/workshop/meson.build
index 9a8c5918d..b5d3f43a1 100644
--- a/operations/workshop/meson.build
+++ b/operations/workshop/meson.build
@@ -14,7 +14,7 @@ gegl_workshop_sources = files(
   'band-tune.c', 
   'gcr.c', 
   'gradient-map.c', 
-  'hstack.c', 
+  'pack.c', 
   'integral-image.c', 
   'rawbayer-load.c', 
   'segment-kmeans.c', 
diff --git a/operations/workshop/pack.c b/operations/workshop/pack.c
new file mode 100644
index 000000000..0513f3110
--- /dev/null
+++ b/operations/workshop/pack.c
@@ -0,0 +1,140 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL 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.
+ *
+ * GEGL 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 GEGL; if not, see <https://www.gnu.org/licenses/>.
+ *
+ * Copyright 2020 Øyvind Kolås <pippin gimp org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+#include <math.h>
+
+#ifdef GEGL_PROPERTIES
+
+property_double  (gap, _("Gap"), 0.0)
+                  description (_("How many pixels of space between items"))
+property_enum (orientation, _("Orientation"), GeglOrientation, gegl_orientation, GEGL_ORIENTATION_HORIZONTAL)
+
+#else
+
+#define GEGL_OP_META
+#define GEGL_OP_NAME     pack 
+#define GEGL_OP_C_SOURCE pack.c
+
+#include "gegl-op.h"
+
+typedef struct
+{
+  GeglNode *over;
+  GeglNode *translate;
+  int width;
+  int height;
+
+} State;
+
+static void
+prepare (GeglOperation *operation)
+{
+  GeglProperties *o = GEGL_PROPERTIES (operation);
+  GeglNode *gegl = operation->node;
+  State *state = o->user_data;
+  if (!state)
+     return;
+
+  GeglNode *input = gegl_node_get_input_proxy (gegl, "input");
+  GeglRectangle in_rect = gegl_node_get_bounding_box (input);
+
+  if (o->orientation == GEGL_ORIENTATION_VERTICAL)
+  {
+    if (state->height != in_rect.height)
+    {
+      state->height = in_rect.height;
+      gegl_node_set (state->translate, "x", 0.0f,
+                                       "y", 1.0f * in_rect.height + o->gap, NULL); 
+    }
+  }
+  else
+  {
+    if (state->width != in_rect.width)
+    {
+      state->width = in_rect.width;
+      gegl_node_set (state->translate, "x", 1.0f * in_rect.width + o->gap,
+                                       "y", 0.0f, NULL); 
+    }
+  }
+}
+
+static void
+update_graph (GeglOperation *operation)
+{
+  GeglProperties *o = GEGL_PROPERTIES (operation);
+  State *state = o->user_data;
+
+  GeglNode *gegl   = operation->node;
+  GeglNode *input  = gegl_node_get_input_proxy  (gegl, "input");
+  GeglNode *aux    = gegl_node_get_input_proxy  (gegl, "aux");
+  GeglNode *output = gegl_node_get_output_proxy (gegl, "output");
+
+  gegl_node_link_many (input, state->over, output, NULL);
+  gegl_node_link_many (aux, state->translate, NULL);
+
+  gegl_node_connect_from (state->over, "aux",
+                          state->translate,  "output");
+}
+
+static void
+attach (GeglOperation *operation)
+{
+  GeglProperties *o = GEGL_PROPERTIES (operation);
+  GeglNode *gegl = operation->node;
+  State *state = g_malloc0 (sizeof (State));
+  o->user_data = state;
+
+  state->over = gegl_node_new_child (gegl, "operation", "gegl:over", NULL);
+  state->translate = gegl_node_new_child (gegl, "operation", "gegl:translate", NULL);
+}
+
+static void
+dispose (GObject *object)
+{
+   GeglProperties  *o     = GEGL_PROPERTIES (object);
+   g_clear_pointer (&o->user_data, g_free);
+   G_OBJECT_CLASS (gegl_op_parent_class)->dispose (object);
+}
+
+static void
+gegl_op_class_init (GeglOpClass *klass)
+{
+  GObjectClass           *object_class;
+  GeglOperationClass     *operation_class;
+  GeglOperationMetaClass *operation_meta_class;
+
+  object_class         = G_OBJECT_CLASS (klass);
+  operation_class      = GEGL_OPERATION_CLASS (klass);
+  operation_meta_class = GEGL_OPERATION_META_CLASS (klass);
+
+  object_class->dispose        = dispose;
+  operation_class->attach      = attach;
+  operation_class->prepare     = prepare;
+  operation_meta_class->update = update_graph;
+
+  gegl_operation_class_set_keys (operation_class,
+    "name",        "gegl:pack",
+    "title",       _("Pack"),
+    "categories",  "layout",
+    "description", _("Packs an image horizontally or vertically next to each other with optional gap, aux 
right of input."),
+    NULL);
+}
+
+#endif
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 525e4dca6..5944f191f 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -285,8 +285,8 @@ operations/workshop/generated/soft-burn.c
 operations/workshop/generated/soft-dodge.c
 operations/workshop/generated/subtractive.c
 operations/workshop/gradient-map.c
-operations/workshop/hstack.c
 operations/workshop/integral-image.c
 operations/workshop/rawbayer-load.c
 operations/workshop/segment-kmeans.c
 operations/workshop/selective-hue-saturation.c
+operations/workshop/pack.c