From a1ad1fc9dbfb69abd485ff53538f5e0d64654390 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Mon, 3 Apr 2023 22:32:31 -0400
Subject: [PATCH] node-editor: Improve the scaling

We only want to scale the main rendering, not whats
shown in the sidebar. Also, make the scale logarithmic.
---
 demos/node-editor/node-editor-window.c  | 31 +++++++++++++++++++------
 demos/node-editor/node-editor-window.ui |  6 ++---
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/demos/node-editor/node-editor-window.c b/demos/node-editor/node-editor-window.c
index 3fe3d818c7..9eb5fcfac6 100644
--- a/demos/node-editor/node-editor-window.c
+++ b/demos/node-editor/node-editor-window.c
@@ -174,6 +174,7 @@ text_changed (GtkTextBuffer    *buffer,
   GtkTextIter iter;
   GtkTextIter start, end;
   float scale;
+  GskRenderNode *big_node;
 
   g_array_remove_range (self->errors, 0, self->errors->len);
   text = get_current_text (self->text_buffer);
@@ -186,13 +187,18 @@ text_changed (GtkTextBuffer    *buffer,
   self->node = gsk_render_node_deserialize (bytes, deserialize_error_func, self);
 
   scale = gtk_scale_button_get_value (GTK_SCALE_BUTTON (self->scale_scale));
-  if (self->node && scale != 1.0)
+  if (self->node && scale != 0.)
     {
-      GskRenderNode *node;
-
-      node = gsk_transform_node_new (self->node, gsk_transform_scale (NULL, scale, scale));
-      gsk_render_node_unref (self->node);
-      self->node = node;
+      scale = pow (2., scale);
+      big_node = gsk_transform_node_new (self->node, gsk_transform_scale (NULL, scale, scale));
+    }
+  else if (self->node)
+    {
+      big_node = gsk_render_node_ref (self->node);
+    }
+  else
+    {
+      big_node = NULL;
     }
 
   g_bytes_unref (bytes);
@@ -204,18 +210,27 @@ text_changed (GtkTextBuffer    *buffer,
       graphene_rect_t bounds;
       guint i;
 
+      snapshot = gtk_snapshot_new ();
+      gsk_render_node_get_bounds (big_node, &bounds);
+      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- bounds.origin.x, - bounds.origin.y));
+      gtk_snapshot_append_node (snapshot, big_node);
+      paintable = gtk_snapshot_free_to_paintable (snapshot, &bounds.size);
+      gtk_picture_set_paintable (GTK_PICTURE (self->picture), paintable);
+      g_clear_object (&paintable);
+
       snapshot = gtk_snapshot_new ();
       gsk_render_node_get_bounds (self->node, &bounds);
       gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- bounds.origin.x, - bounds.origin.y));
       gtk_snapshot_append_node (snapshot, self->node);
       paintable = gtk_snapshot_free_to_paintable (snapshot, &bounds.size);
-      gtk_picture_set_paintable (GTK_PICTURE (self->picture), paintable);
+
       for (i = 0; i < g_list_model_get_n_items (G_LIST_MODEL (self->renderers)); i++)
         {
           gpointer item = g_list_model_get_item (G_LIST_MODEL (self->renderers), i);
           gtk_renderer_paintable_set_paintable (item, paintable);
           g_object_unref (item);
         }
+
       g_clear_object (&paintable);
     }
   else
@@ -223,6 +238,8 @@ text_changed (GtkTextBuffer    *buffer,
       gtk_picture_set_paintable (GTK_PICTURE (self->picture), NULL);
     }
 
+  g_clear_pointer (&big_node, gsk_render_node_unref);
+
   gtk_text_buffer_get_start_iter (self->text_buffer, &iter);
 
   while (!gtk_text_iter_is_end (&iter))
diff --git a/demos/node-editor/node-editor-window.ui b/demos/node-editor/node-editor-window.ui
index 34d4452a4a..45a37cd952 100644
--- a/demos/node-editor/node-editor-window.ui
+++ b/demos/node-editor/node-editor-window.ui
@@ -163,9 +163,9 @@
             <property name="valign">center</property>
             <property name="adjustment">
               <object class="GtkAdjustment">
-                <property name="lower">1</property>
-                <property name="value">1</property>
-                <property name="upper">10</property>
+                <property name="lower">-4</property>
+                <property name="value">0</property>
+                <property name="upper">4</property>
                 <property name="step-increment">0.1</property>
                 <property name="page-increment">0.5</property>
               </object>
-- 
2.30.2