app: Layer expansion while using ink tool

Now layers will expand when trying to draw beyond layer borders with ink tool.
Tool options similar to paint tools have been added (expand_use and
expand_amount).

app/paint/gimpink-blob.c

@@ -466,6 +466,21 @@ gimp_blob_duplicate (GimpBlob *b)
   return g_memdup2 (b, sizeof (GimpBlob) +  sizeof (GimpBlobSpan) * (b->height - 1));
 }
 
+void
+gimp_blob_move (GimpBlob *b,
+                gint      x,
+                gint      y)
+{
+  gint i = 0;
+
+  b->y += y;
+  for (i = 0; i < b->height; i++)
+    {
+      b->data[i].left  += x;
+      b->data[i].right += x;
+    }
+}
+
 #if 0
 void
 gimp_blob_dump (GimpBlob *b)

app/paint/gimpink-blob.h

@@ -82,6 +82,9 @@ void       gimp_blob_bounds       (GimpBlob      *b,
 GimpBlob * gimp_blob_convex_union (GimpBlob      *b1,
                                    GimpBlob      *b2);
 GimpBlob * gimp_blob_duplicate    (GimpBlob      *b);
+void       gimp_blob_move         (GimpBlob      *b,
+                                   gint           x,
+                                   gint           y);
 
 
 #endif /* __GIMP_INK_BLOB_H__ */

app/paint/gimpink.c

@@ -238,17 +238,40 @@ gimp_ink_get_paint_buffer (GimpPaintCore    *paint_core,
                            gint             *paint_width,
                            gint             *paint_height)
 {
-  GimpInk *ink = GIMP_INK (paint_core);
-  gint     x, y;
-  gint     width, height;
-  gint     dwidth, dheight;
-  gint     x1, y1, x2, y2;
+  GimpInk    *ink = GIMP_INK (paint_core);
+  gint        x, y;
+  gint        width, height;
+  gint        dwidth, dheight;
+  gint        x1, y1, x2, y2;
+  gint        offset_change_x, offset_change_y;
+  GimpCoords  new_coords;
+  GList      *iter;
 
   gimp_blob_bounds (ink->cur_blob, &x, &y, &width, &height);
 
+  x1 = x / SUBSAMPLE - 1;
+  y1 = y / SUBSAMPLE - 1;
+  x2 = (x + width)  / SUBSAMPLE + 2;
+  y2 = (y + height) / SUBSAMPLE + 2;
+
+  gimp_paint_core_expand_drawable (paint_core, drawable, paint_options,
+                                   x1, x2, y1, y2,
+                                   &offset_change_x, &offset_change_y);
+
   dwidth  = gimp_item_get_width  (GIMP_ITEM (drawable));
   dheight = gimp_item_get_height (GIMP_ITEM (drawable));
 
+  if (offset_change_x || offset_change_y)
+    {
+      x += SUBSAMPLE * offset_change_x;
+      y += SUBSAMPLE * offset_change_y;
+
+      for (iter = ink->last_blobs; iter; iter = g_list_next (iter))
+        gimp_blob_move (iter->data,
+                        SUBSAMPLE * offset_change_x,
+                        SUBSAMPLE * offset_change_y);
+    }
+
   x1 = CLAMP (x / SUBSAMPLE - 1,            0, dwidth);
   y1 = CLAMP (y / SUBSAMPLE - 1,            0, dheight);
   x2 = CLAMP ((x + width)  / SUBSAMPLE + 2, 0, dwidth);
@@ -418,6 +441,7 @@ gimp_ink_motion (GimpPaintCore    *paint_core,
   gimp_pickable_srgb_to_image_color (GIMP_PICKABLE (drawable),
                                      &foreground, &foreground);
   color = gimp_gegl_color_new (&foreground, gimp_drawable_get_space (drawable));
+  ink->blobs_to_render = blobs_to_render;
 
   for (i = 0; i < n_strokes; i++)
     {

app/paint/gimpink.h

@@ -37,10 +37,11 @@ struct _GimpInk
 {
   GimpPaintCore  parent_instance;
 
-  GList         *start_blobs;  /*  starting blobs per stroke (for undo) */
+  GList         *start_blobs;      /*  starting blobs per stroke (for undo) */
 
-  GimpBlob      *cur_blob;     /*  current blob                         */
-  GList         *last_blobs;   /*  blobs for last stroke positions      */
+  GimpBlob      *cur_blob;         /*  current blob                         */
+  GList         *last_blobs;       /*  blobs for last stroke positions      */
+  GList         *blobs_to_render;
 };
 
 struct _GimpInkClass

app/tools/gimpinkoptions-gui.c

@@ -129,6 +129,18 @@ gimp_ink_options_gui (GimpToolOptions *tool_options)
   gtk_container_add (GTK_CONTAINER (frame), editor);
   gtk_widget_show (editor);
 
+  /* Extend layer options */
+  scale = gimp_prop_spin_scale_new (config, "expand-amount",
+                                    1, 10, 2);
+  gimp_spin_scale_set_constrain_drag (GIMP_SPIN_SCALE (scale), TRUE);
+  gimp_spin_scale_set_scale_limits (GIMP_SPIN_SCALE (scale), 1.0, 1000.0);
+  gimp_spin_scale_set_gamma (GIMP_SPIN_SCALE (scale), 1.0);
+
+  frame = gimp_prop_expanding_frame_new (config, "expand-use", NULL,
+                                         scale, NULL);
+  gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
+  gtk_widget_show (frame);
+
   gimp_config_connect (config, G_OBJECT (editor), "blob-type");
   gimp_config_connect (config, G_OBJECT (editor), "blob-aspect");
   gimp_config_connect (config, G_OBJECT (editor), "blob-angle");