Remove View.blending (#31)

With PyGfx v0.13.0, they removed blending mode from the renderer in
favor of alpha parameters on each material in the scene. This aligns
more closely with how VisPy does things, which is important for us
because it ignored View.blending anyways!

All of this is to say that I think it's worth (a) removing View.blending
for now to avoid the errors and (b) coming up with a new mechanism for
capturing transparency within the model (when we have a use for it?)

Author: gselzer

examples/basic_scene.py

@@ -10,7 +10,6 @@
     add_imgui_controls = None  # type: ignore[assignment]
 
 view = snx.View(
-    blending="default",
     scene=snx.Scene(
         children=[
             snx.Image(

examples/basic_volume.py

@@ -11,7 +11,6 @@
     data = np.random.randint(0, 2, (3, 3, 3)).astype(np.uint16)
 
 view = snx.View(
-    blending="default",
     scene=snx.Scene(
         children=[
             snx.Volume(

src/scenex/adaptors/_base.py

@@ -226,6 +226,4 @@ def _snx_set_scene(self, arg: model.Scene, /) -> None: ...
     @abstractmethod
     def _snx_set_camera(self, arg: model.Camera, /) -> None: ...
     @abstractmethod
-    def _snx_set_blending(self, arg: model.BlendMode, /) -> None: ...
-    @abstractmethod
     def _snx_render(self) -> NDArray: ...

src/scenex/adaptors/_pygfx/_view.py

@@ -18,12 +18,6 @@
     from . import _camera, _canvas, _scene
 
 logger = logging.getLogger("scenex.adaptors.pygfx")
-BLENDING_MAP = {
-    "default": "default",
-    "opaque": "opaque",
-    "alpha": "ordered1",
-    "additive": "additive",
-}
 
 
 class View(ViewAdaptor):
@@ -42,16 +36,12 @@ def __init__(self, view: model.View, **backend_kwargs: Any) -> None:
 
         self._snx_set_scene(view.scene)
         self._snx_set_camera(view.camera)
-        self._snx_set_blending(view.blending)
         # TODO: this is needed... but breaks tests until we deal with Layout better.
         # self._snx_set_background_color(view.layout.background_color)
 
     def _snx_get_native(self) -> pygfx.Viewport:
         return pygfx.Viewport(self._renderer)
 
-    def _snx_set_blending(self, arg: model.BlendMode) -> None:
-        self._renderer.blend_mode = BLENDING_MAP.get(arg, "default")
-
     def _snx_set_visible(self, arg: bool) -> None:
         pass
 

src/scenex/adaptors/_vispy/_view.py

@@ -22,14 +22,6 @@
     from . import _camera, _scene
 
 
-BLENDING_MAP = {
-    "default": "default",
-    "opaque": "opaque",
-    "alpha": "ordered1",
-    "additive": "additive",
-}
-
-
 class View(ViewAdaptor):
     """View interface for vispy Backend.
 
@@ -45,16 +37,10 @@ def __init__(self, view: model.View, **backend_kwargs: Any) -> None:
 
         self._snx_set_camera(view.camera)
         self._snx_set_scene(view.scene)
-        self._snx_set_blending(view.blending)
 
     def _snx_get_native(self) -> Any:
         return self._vispy_viewbox
 
-    def _snx_set_blending(self, arg: model.BlendMode) -> None:
-        # FIXME: This is tricky - needs to be passed to set_gl_state for each scene
-        # node.
-        pass
-
     def _snx_set_visible(self, arg: bool) -> None:
         pass
 

src/scenex/model/__init__.py

@@ -22,11 +22,10 @@
 from ._nodes.scene import Scene
 from ._nodes.volume import RenderMode, Volume
 from ._transform import Transform
-from ._view import BlendMode, View
+from ._view import View
 
 __all__ = [
     "AnyNode",
-    "BlendMode",
     "Camera",
     "CameraType",
     "Canvas",

src/scenex/model/_view.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import logging
-from typing import TYPE_CHECKING, Any, Literal, cast
+from typing import TYPE_CHECKING, Any, cast
 
 from pydantic import ConfigDict, Field, PrivateAttr
 
@@ -22,10 +22,6 @@
 logger = logging.getLogger(__name__)
 
 
-# just a random/basic selection of blend modes for now
-BlendMode = Literal["default", "opaque", "alpha", "additive"]
-
-
 class View(EventedBase):
     """An association of a scene and a camera.
 
@@ -41,11 +37,6 @@ class View(EventedBase):
     scene: Scene = Field(default_factory=Scene)
     camera: Camera = Field(default_factory=Camera)
     layout: Layout = Field(default_factory=Layout, frozen=True)
-    blending: BlendMode = Field(
-        default="default",
-        description="The blending mode to use when rendering the view. "
-        "Must be one of 'default', 'opaque', 'alpha', or 'additive'.",
-    )
     visible: bool = Field(default=True, description="Whether the view is visible.")
 
     _canvas: Canvas | None = PrivateAttr(None)

tests/conftest.py

@@ -66,4 +66,4 @@ def basic_scene(
 
 @pytest.fixture
 def basic_view(basic_scene: snx.Scene) -> snx.View:
-    return snx.View(blending="default", scene=basic_scene)
+    return snx.View(scene=basic_scene)