Move BlockAttributes storage out of Primitive.

Motivation:

* Many blocks have all default attributes. This way, the primitive need
  not store all attributes (is smaller in memory), is conceptually
  simpler, and leans less heavily on “default values aren’t serialized”.
* Sometimes you want to set attributes on an already-modified block,
  like a `Composite` of several more basic parts.
* `BlockAttributes` itself is an inelegant bundle of many different
  concerns, which has needed to change incompatibly. (For example, light
  emission used to be an attribute and now is strictly per-voxel.) After
  this change, we can, if we choose, completely hide or remove
  `BlockAttributes`; we would replace creating it with a bunch of
  modifiers which override individual attributes, and replace reading
  it with individual methods on `EvaluatedBlock`.

CHANGELOG.md

@@ -7,7 +7,8 @@
 - `all-is-cubes` library:
     - Block inventories are now more functional.
         - `block::Block::with_inventory` attaches inventory to a block.
-        - `inv::InvInBlock`, stored in `block::BlockAtributes::inventory`, describes the size and rendering such inventories should have.
+        - `inv::InvInBlock`, stored in `block::BlockAttributes::inventory`, describes the size and rendering such inventories should have.
+    - `block::Modifier::Attributes` allows overriding block attributes.
 
 ### Changed
 
@@ -22,6 +23,10 @@
 
 ### Removed
 
+- `all-is-cubes` library:
+    - `block::Primitive` no longer contains `BlockAttributes` in any of its variants.
+      The new means of specifying attributes is `block::Modifier::Attributes`.
+
 ## 0.8.0 (2024-07-08)
 
 ### Added

all-is-cubes-content/src/blocks.rs

@@ -9,7 +9,7 @@ use exhaust::Exhaust;
 use rand::{Rng as _, SeedableRng as _};
 
 use all_is_cubes::block::{
-    self, AnimationHint, Atom, Block, BlockCollision, BlockDefTransaction, Primitive,
+    self, AnimationHint, Block, BlockCollision, BlockDefTransaction, Primitive,
     Resolution::*, RotationPlacementRule, TickAction, AIR,
 };
 use all_is_cubes::color_block;
@@ -500,10 +500,7 @@ pub async fn install_demo_blocks(
     // Join up blinker blocks
     for state in bool::exhaust() {
         modify_def(&provider_for_patch[BecomeBlinker(state)], |block| {
-            let Primitive::Atom(Atom { attributes, .. }) = block.primitive_mut() else {
-                panic!("blinker not atom");
-            };
-            attributes.tick_action = Some(TickAction {
+            block.freezing_get_attributes_mut().tick_action = Some(TickAction {
                 operation: Operation::Become(provider_for_patch[BecomeBlinker(!state)].clone()),
                 schedule: time::Schedule::from_period(NonZeroU16::new(60).unwrap()),
             });
@@ -514,10 +511,7 @@ pub async fn install_demo_blocks(
     for state in bool::exhaust() {
         for ctor in [Lamp, Sconce] {
             modify_def(&provider_for_patch[ctor(state)], |block| {
-                let Primitive::Recur { attributes, .. } = block.primitive_mut() else {
-                    panic!("lamp not recur");
-                };
-                attributes.activation_action =
+                block.freezing_get_attributes_mut().activation_action =
                     Some(Operation::Become(provider_for_patch[ctor(!state)].clone()));
             });
         }
@@ -526,9 +520,6 @@ pub async fn install_demo_blocks(
     // Join up explosion blocks
     for i in i8::exhaust() {
         modify_def(&provider_for_patch[Explosion(i)], |block| {
-            let Primitive::Recur { attributes, .. } = block.primitive_mut() else {
-                panic!("explosion not atom");
-            };
             let neighbor_ops: Arc<[(Cube, Operation)]> = if i > 22 {
                 // Expire because we're invisible by now
                 [(Cube::ORIGIN, Operation::Become(AIR))].into()
@@ -574,7 +565,7 @@ pub async fn install_demo_blocks(
                     [(Cube::ORIGIN, next.clone())].into()
                 }
             };
-            attributes.tick_action = Some(TickAction {
+            block.freezing_get_attributes_mut().tick_action = Some(TickAction {
                 operation: Operation::Neighbors(neighbor_ops),
                 schedule: time::Schedule::from_period(NonZeroU16::new(2).unwrap()),
             });

all-is-cubes-content/src/city.rs

@@ -534,10 +534,11 @@ fn place_one_exhibit<I: Instant>(
                     bounds_for_info_voxels,
                     universe.insert_anonymous(exhibit_info_space),
                     info_resolution,
-                    BlockAttributes {
+                    [BlockAttributes {
                         display_name: "Exhibit Name".into(),
                         ..Default::default()
-                    },
+                    }
+                    .into()],
                 ))),
             ],
         });

all-is-cubes-content/src/city/exhibits.rs

@@ -284,11 +284,13 @@ fn KNOT(ctx: Context<'_>) {
     })?;
     let space = space_to_blocks(
         resolution,
-        BlockAttributes {
-            display_name: ctx.exhibit.name.into(),
-            ..BlockAttributes::default()
-        },
         txn.insert_anonymous(drawing_space),
+        &mut |block| {
+            block.with_modifier(BlockAttributes {
+                display_name: ctx.exhibit.name.into(),
+                ..BlockAttributes::default()
+            })
+        },
     )?;
     Ok((space, txn))
 }

all-is-cubes-content/src/menu.rs

@@ -4,7 +4,7 @@ use alloc::vec::Vec;
 use strum::IntoEnumIterator;
 
 use all_is_cubes::arcstr;
-use all_is_cubes::block::{BlockAttributes, Resolution};
+use all_is_cubes::block::Resolution;
 use all_is_cubes::character::Spawn;
 use all_is_cubes::content::palette;
 use all_is_cubes::euclid::Vector3D;
@@ -39,7 +39,7 @@ pub(crate) async fn template_menu(
         logo_text_space.bounds(),
         universe.insert_anonymous(logo_text_space),
         Resolution::R8,
-        BlockAttributes::default(),
+        [],
     );
 
     let mut vertical_widgets: Vec<vui::WidgetTree> = Vec::with_capacity(10);

all-is-cubes-ui/src/editor.rs

@@ -60,7 +60,6 @@ fn inspect_primitive(primitive: &block::Primitive) -> vui::WidgetTree {
     let (name, details): (ArcStr, vui::WidgetTree) = match primitive {
         block::Primitive::Indirect(block_def) => (literal!("Indirect"), inspect_handle(block_def)),
         block::Primitive::Atom(block::Atom {
-            attributes,
             color,
             emission,
             collision,
@@ -72,14 +71,12 @@ fn inspect_primitive(primitive: &block::Primitive) -> vui::WidgetTree {
                     "\
                         Color: {color:?}\n\
                         Emission: {emission:?}\n\
-                        Collision: {collision:?}\n\
-                        Attributes: {attributes:#?}\
+                        Collision: {collision:?}\
                         "
                 ))],
             }),
         ),
         block::Primitive::Recur {
-            attributes,
             space,
             offset,
             resolution,
@@ -92,8 +89,7 @@ fn inspect_primitive(primitive: &block::Primitive) -> vui::WidgetTree {
                     paragraph(arcstr::format!(
                         "\
                         Resolution: {resolution}\n\
-                        Offset: {offset:?}\n\
-                        Attributes: {attributes:#?}\
+                        Offset: {offset:?}\
                         "
                     )),
                 ],
@@ -142,6 +138,9 @@ fn inspect_modifier(block: &Block, modifier_index: usize) -> vui::WidgetTree {
         .truncate(modifier_index + 1);
 
     let (name, details) = match modifier {
+        block::Modifier::Attributes(a) => {
+            (literal!("Attributes"), paragraph(arcstr::format!("{a:?}")))
+        }
         block::Modifier::Quote(q) => (literal!("Quote"), paragraph(arcstr::format!("{q:?}"))),
         block::Modifier::Rotate(rotation) => (
             literal!("Rotate"),

all-is-cubes-ui/src/vui/page.rs

@@ -2,7 +2,7 @@ use alloc::sync::Arc;
 
 use all_is_cubes::arcstr::ArcStr;
 use all_is_cubes::block::{text, AIR};
-use all_is_cubes::block::{Block, BlockAttributes, Resolution};
+use all_is_cubes::block::{Block, Resolution};
 use all_is_cubes::color_block;
 use all_is_cubes::content::palette;
 use all_is_cubes::euclid::{size2, Size2D};
@@ -312,7 +312,7 @@ pub(crate) mod parts {
             space.bounds(),
             universe.insert_anonymous(space),
             resolution,
-            BlockAttributes::default(),
+            [],
         )))
     }
 

all-is-cubes-ui/src/vui/widgets/voxels.rs

@@ -1,6 +1,6 @@
 use alloc::sync::Arc;
 
-use all_is_cubes::block::{Block, BlockAttributes, Primitive, Resolution};
+use all_is_cubes::block::{self, Block, Primitive, Resolution};
 use all_is_cubes::euclid::Size3D;
 use all_is_cubes::math::{GridAab, GridMatrix, GridPoint, GridSizeCoord, GridVector};
 use all_is_cubes::space::{Space, SpaceTransaction};
@@ -17,7 +17,7 @@ pub struct Voxels {
     space: Handle<Space>,
     region: GridAab,
     scale: Resolution,
-    block_attributes: BlockAttributes,
+    modifiers: Vec<block::Modifier>,
 }
 
 impl Voxels {
@@ -26,19 +26,19 @@ impl Voxels {
     /// When the `region`'s dimensions are not multiples of `scale`, their alignment within the
     /// block grid will be determined by the layout gravity. Note that areas of `space` outside of
     /// `region` may be displayed in that case.
-    pub const fn new(
+    pub fn new(
         region: GridAab,
         space: Handle<Space>,
         scale: Resolution,
-        block_attributes: BlockAttributes,
+        modifiers: impl IntoIterator<Item = block::Modifier>,
     ) -> Self {
         // Design note: We could take `region` from `space` but that'd require locking it,
         // and the caller is very likely to already have that information.
         Self {
             space,
             region,
             scale,
-            block_attributes,
+            modifiers: modifiers.into_iter().collect(),
         }
     }
 }
@@ -92,15 +92,15 @@ impl vui::Widget for Voxels {
 
         let mut txn = SpaceTransaction::default();
         for cube in position.bounds.interior_iter() {
-            txn.at(cube)
-                .overwrite(Block::from_primitive(Primitive::Recur {
-                    attributes: self.block_attributes.clone(),
-                    offset: block_to_voxels_transform
-                        .transform_cube(cube)
-                        .lower_bounds(),
-                    resolution: self.scale,
-                    space: self.space.clone(),
-                }));
+            let mut block = Block::from_primitive(Primitive::Recur {
+                offset: block_to_voxels_transform
+                    .transform_cube(cube)
+                    .lower_bounds(),
+                resolution: self.scale,
+                space: self.space.clone(),
+            });
+            block.modifiers_mut().clone_from(&self.modifiers);
+            txn.at(cube).overwrite(block);
         }
         super::OneshotController::new(txn)
     }
@@ -119,7 +119,6 @@ mod tests {
     fn test_voxels_widget(
         voxel_space_bounds: GridAab,
         grant: vui::LayoutGrant,
-        attributes: BlockAttributes,
     ) -> (Option<GridAab>, Space) {
         let mut universe = Universe::new();
         instantiate_widget(
@@ -128,7 +127,7 @@ mod tests {
                 voxel_space_bounds,
                 universe.insert_anonymous(Space::builder(voxel_space_bounds).build()),
                 R8,
-                attributes,
+                [],
             ),
         )
     }
@@ -141,7 +140,6 @@ mod tests {
         let _output = test_voxels_widget(
             v_space_bounds,
             vui::LayoutGrant::new(GridAab::single_cube(output_origin)),
-            BlockAttributes::default(),
         );
         // TODO assertions about resulting blocks
     }
@@ -158,16 +156,14 @@ mod tests {
             bounds: GridAab::from_lower_size(output_origin, [3, 3, 3]),
             gravity: Vector3D::new(Align::Low, Align::Center, Align::High),
         };
-        let (output_bounds, output) =
-            test_voxels_widget(v_space_bounds, grant, BlockAttributes::default());
+        let (output_bounds, output) = test_voxels_widget(v_space_bounds, grant);
         assert_eq!(
             output_bounds.unwrap(),
             GridAab::from_lower_size([100, 101, 101], [1, 1, 2])
         );
         // Expect two adjacent recursive blocks
         match *output[[100, 101, 101]].primitive() {
             Primitive::Recur {
-                attributes: _,
                 offset,
                 resolution,
                 space: _,
@@ -179,7 +175,6 @@ mod tests {
         }
         match *output[[100, 101, 102]].primitive() {
             Primitive::Recur {
-                attributes: _,
                 offset,
                 resolution,
                 space: _,