Enablers for adding and removing layers to the scene at run time

Adding, removing and reordering layers is almost in place now. Some
things are still missing when it comes to cameras since the mvp in the
vertex shaders for layers introduced on-the-fly is incorrect.

Extend also setparent() in the console to allow inserting new subtrees
at arbitrary places. Q3DSGraphObject already has the necessary APIs
(insertChildNodeAfter and friends).

Therefore, doing

object(newlayer, newlayer, Layer, null, Slide1)
object(newlayer_cam, newlayer_cam, Camera, newlayer, Slide1)
...

setparent(newlayer, Scene)

Adds the new layer after all existing layers (and thus to the bottom of
the stack since the 3D Studio object tree (and the editor's
visualization of the tree) assumes front-to-back ordering for the layers
which is weird but that's what it is).

To instead add to the top (i.e. before the existing Layer children of
Scene), we can now do:

setparent(newlayer, Scene, null)

This also matches what clicking the "Add new layer" button in the editor
would do.

To implement moving layers around (to change their ordering), one can
now simply do setparent(newlayer, Scene, SomeOtherLayer) (or the equivalent
using the Q3DSGraphObject APIs) in order to move newlayer after SomeOtherLayer.

Change-Id: I9c832e4299cb7398d97a799dce5eaa3cd5518a77
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

2 files changed, 30 insertions, 0 deletions

diff --git a/tests/scripts/newlayer.drgscr b/tests/scripts/newlayer.drgscr
new file mode 100644
index 0000000..ae7e556
--- /dev/null
+++ b/tests/scripts/newlayer.drgscr
@@ -0,0 +1,17 @@
+object(newlayer, newlayer, Layer, null, Slide1)
+
+object(newlayer_cam, newlayer_cam, Camera, newlayer, Slide1)
+// the default position does not work since the property is shared with nodes and those use 0 0 0 as the default,
+// unlike the expected 0 0 -600 for cameras. so must specify it explicitly.
+set(newlayer_cam, position, 0 0 -600)
+
+// must have a light to see something
+object(newlayer_light, newlayer_light, Light, newlayer, Slide1)
+
+// add some text
+object(newlayer_text, newlayer_text, Text, newlayer, Slide1)
+set(newlayer_text, textstring, New Layer!)
+set(newlayer_text, textcolor, 0 1 0)
+
+// use prependChildNode, i.e. add as the top-most (front) layer
+setparent(newlayer, Scene, null)
diff --git a/tests/scripts/newlayer_direct.drgscr b/tests/scripts/newlayer_direct.drgscr
new file mode 100644
index 0000000..4688a2b
--- /dev/null
+++ b/tests/scripts/newlayer_direct.drgscr
@@ -0,0 +1,13 @@
+// Here the layer and its children are connected one by one to the scene right away as they are created.
+// will end up as the bottom layer (last child of Scene)
+
+object(newlayer, newlayer, Layer, Scene, Slide1)
+
+object(newlayer_cam, newlayer_cam, Camera, newlayer, Slide1)
+set(newlayer_cam, position, 0 0 -600)
+
+object(newlayer_light, newlayer_light, Light, newlayer, Slide1)
+
+object(newlayer_text, newlayer_text, Text, newlayer, Slide1)
+set(newlayer_text, textstring, New Layer!)
+set(newlayer_text, textcolor, 0 1 0)