content: Add ability to place exhibits underground.

This is not yet used due to various missing details:

* Decide what wall surfaces underground exhibits should have.
  (Probably the enclosure should not have air but walls.)
* Add exhibit fields to define what kind of entrance doorway they want.
* Generate appropriate entranceway blocks rather than Road.
* Decide how to handle when the exhibit is tall enough to stick out.
* Add access stairs-or-something down.

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

@@ -70,7 +70,6 @@ pub(crate) async fn demo_city<I: Instant>(
     let lamp_spacing = 20;
     let sky_height = 30;
     let ground_depth = 30; // TODO: wavy_landscape is forcing us to have extra symmetry here
-    let underground_floor_y = -5;
     let space_size = params.size.unwrap_or(GridVector::new(160, 60, 160));
     let bounds = GridAab::from_lower_upper(
         [-space_size.x / 2, -ground_depth, -space_size.z / 2],
@@ -192,7 +191,7 @@ pub(crate) async fn demo_city<I: Instant>(
             // Dig underground passages
             // TODO: They need a connection to the surface
             for p in -road_radius..=road_radius {
-                for y in underground_floor_y..0 {
+                for y in CityPlanner::UNDERGROUND_FLOOR_Y..0 {
                     space.set(
                         step.cube_ahead() + perpendicular * p + GridVector::new(0, y, 0),
                         &AIR,
@@ -354,12 +353,11 @@ async fn place_exhibits_in_city<I: Instant>(
         };
         exhibit_progress.progress(0.33).await;
 
-        // Now that we know the size of the exhibit, find a place for it.
+        // Now that we know the size of the exhibit, find a place for it that fits its bounds.
         let exhibit_footprint = exhibit_space.bounds();
-
         let enclosure_footprint = exhibit_footprint.expand(FaceMap::repeat(1));
 
-        let Some(plot_transform) = planner.find_plot(enclosure_footprint) else {
+        let Some(plot_transform) = planner.find_plot(enclosure_footprint, exhibit.placement) else {
             log::error!("Out of city space!");
             break 'exhibit;
         };
@@ -372,7 +370,9 @@ async fn place_exhibits_in_city<I: Instant>(
             enclosure_at_plot.lower_bounds(),
             [
                 enclosure_at_plot.upper_bounds().x,
-                1.max(plot.lower_bounds().y), // handles case where plot is floating
+                // max()ing handles the case where the plot is floating but should still
+                // have enclosure floor
+                exhibit.placement.floor().max(plot.lower_bounds().y),
                 enclosure_at_plot.upper_bounds().z,
             ],
         );
@@ -591,10 +591,27 @@ fn place_lamppost(
 pub(crate) struct Exhibit {
     pub name: &'static str,
     pub subtitle: &'static str,
+    pub placement: Placement,
     pub factory:
         for<'a> fn(&'a Exhibit, &'a mut Universe) -> BoxFuture<'a, Result<Space, InGenError>>,
 }
 
+#[derive(Clone, Copy, Debug)]
+pub(crate) enum Placement {
+    Surface,
+    #[allow(unused)] // TODO: polish this and then use it
+    Underground,
+}
+
+impl Placement {
+    fn floor(self) -> GridCoordinate {
+        match self {
+            Placement::Surface => CityPlanner::SURFACE_Y,
+            Placement::Underground => CityPlanner::UNDERGROUND_FLOOR_Y,
+        }
+    }
+}
+
 /// Generate a Space containing text voxels to put on the signboard for an exhibit.
 ///
 /// The space's bounds extend upward from [0, 0, 0].
@@ -660,13 +677,20 @@ impl CityPlanner {
     const PLOT_FRONT_RADIUS: GridCoordinate = Self::LAMP_POSITION_RADIUS;
     const GAP_BETWEEN_PLOTS: GridCoordinate = 1;
 
+    const SURFACE_Y: GridCoordinate = 1;
+    const UNDERGROUND_FLOOR_Y: GridCoordinate = -10;
+
     pub fn new(space_bounds: GridAab) -> Self {
         let city_radius = space_bounds.upper_bounds().x; // TODO: compare everything and take the max
 
         let mut occupied_plots = Vec::new();
         let road = GridAab::from_lower_upper(
-            [-Self::ROAD_RADIUS, 0, -city_radius],
-            [Self::ROAD_RADIUS + 1, 2, city_radius + 1],
+            [
+                -Self::ROAD_RADIUS,
+                Self::UNDERGROUND_FLOOR_Y - 1,
+                -city_radius,
+            ],
+            [Self::ROAD_RADIUS + 1, Self::SURFACE_Y + 2, city_radius + 1],
         );
         occupied_plots.push(road);
         occupied_plots.push(road.transform(GridRotation::CLOCKWISE.into()).unwrap());
@@ -677,7 +701,7 @@ impl CityPlanner {
         }
     }
 
-    pub fn find_plot(&mut self, plot_shape: GridAab) -> Option<Gridgid> {
+    pub fn find_plot(&mut self, plot_shape: GridAab, placement: Placement) -> Option<Gridgid> {
         // TODO: We'd like to resume the search from _when we left off_, but that's tricky since a
         // smaller plot might fit where a large one didn't. So, quadratic search it is for now.
         for d in 0..=self.city_radius {
@@ -692,7 +716,7 @@ impl CityPlanner {
 
                     let mut transform = Gridgid::from_translation(GridVector::new(
                         d,
-                        1,
+                        placement.floor(),
                         if left_side {
                             -Self::PLOT_FRONT_RADIUS - plot_shape.upper_bounds().z
                         } else {

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

@@ -47,9 +47,10 @@ use all_is_cubes::{
 use all_is_cubes::{include_image, rgb_const, rgba_const};
 
 use crate::alg::{four_walls, voronoi_pattern};
+use crate::city::{Exhibit, Placement};
 use crate::{
     make_slab, make_some_blocks, make_some_voxel_blocks, palette, tree, AnimatedVoxels, DemoBlocks,
-    Exhibit, Fire, LandscapeBlocks,
+    Fire, LandscapeBlocks,
 };
 
 /// All exhibits which will show up in [`crate::UniverseTemplate::DemoCity`].
@@ -100,6 +101,7 @@ macro_rules! exhibit {
     subtitle:
         "Test depth sorting and blending.\n\
         Lighting of volumes still needs work.",
+    placement: Placement::Surface,
 )]
 async fn TRANSPARENCY_LARGE(_: &Exhibit, _universe: &mut Universe) {
     let mut space = Space::empty(GridAab::from_lower_size([-3, 0, -3], [7, 5, 7]));
@@ -135,6 +137,7 @@ async fn TRANSPARENCY_LARGE(_: &Exhibit, _universe: &mut Universe) {
     subtitle:
         "Transparency in complex blocks is not correctly implemented.\n\
         We also need something for surface properties.",
+    placement: Placement::Surface,
 )]
 async fn TRANSPARENCY_SMALL(_: &Exhibit, universe: &mut Universe) {
     let footprint = GridAab::from_lower_size([0, 0, 0], [7, 4, 7]);
@@ -217,6 +220,7 @@ async fn TRANSPARENCY_SMALL(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Knot",
     subtitle: "Complex voxel shape",
+    placement: Placement::Surface,
 )]
 async fn KNOT(this: &Exhibit, universe: &mut Universe) {
     let footprint = GridAab::from_lower_size([-2, -2, -1], [5, 5, 3]);
@@ -291,6 +295,7 @@ async fn KNOT(this: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Text",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn TEXT(_: &Exhibit, universe: &mut Universe) {
     let space = draw_to_blocks(
@@ -313,6 +318,7 @@ async fn TEXT(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Animation",
     subtitle: "Blocks whose definition is animated",
+    placement: Placement::Surface,
 )]
 async fn ANIMATION(_: &Exhibit, universe: &mut Universe) {
     let demo_blocks = BlockProvider::<DemoBlocks>::using(universe)?;
@@ -384,6 +390,7 @@ async fn ANIMATION(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Collision",
     subtitle: "Test cases for character/world collision",
+    placement: Placement::Surface,
 )]
 async fn COLLISION(_: &Exhibit, universe: &mut Universe) {
     let half_block = make_slab(universe, 2, R4);
@@ -433,6 +440,7 @@ async fn COLLISION(_: &Exhibit, universe: &mut Universe) {
     subtitle:
         "Voxel blocks can be subdivided into\n\
         powers of 2 from 2 to 256.",
+    placement: Placement::Surface,
 )]
 async fn RESOLUTIONS(_: &Exhibit, universe: &mut Universe) {
     let footprint = GridAab::from_lower_size([0, 0, 0], [5, 3, 3]);
@@ -496,6 +504,7 @@ async fn RESOLUTIONS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "World's Smallest Voxel",
     subtitle: "1/128th the length of a standard block",
+    placement: Placement::Surface,
 )]
 async fn SMALLEST(_: &Exhibit, universe: &mut Universe) {
     let demo_blocks = BlockProvider::<DemoBlocks>::using(universe)?;
@@ -528,6 +537,7 @@ async fn SMALLEST(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Rotations",
     subtitle: "Rotated blocks and GridRotation::from_to()",
+    placement: Placement::Surface,
 )]
 async fn ROTATIONS(_: &Exhibit, universe: &mut Universe) {
     let demo_blocks = BlockProvider::<DemoBlocks>::using(universe)?;
@@ -577,6 +587,7 @@ async fn ROTATIONS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Modifier::Zoom",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn ZOOM(_: &Exhibit, universe: &mut Universe) {
     let demo_blocks = BlockProvider::<DemoBlocks>::using(universe)?;
@@ -613,6 +624,7 @@ async fn ZOOM(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Modifier::Composite",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn COMPOSITE(_: &Exhibit, universe: &mut Universe) {
     let demo_blocks = BlockProvider::<DemoBlocks>::using(universe)?;
@@ -695,6 +707,7 @@ async fn COMPOSITE(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Modifier::Move",
     subtitle: "Stationary but not animated cases.",
+    placement: Placement::Surface,
 )]
 async fn MOVED_BLOCKS(_: &Exhibit, universe: &mut Universe) {
     let mut space = Space::empty(GridAab::from_lower_upper([0, 0, -3], [16, 2, 3]));
@@ -729,6 +742,7 @@ async fn MOVED_BLOCKS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Colors",
     subtitle: "RGB cube of 5 linear color steps",
+    placement: Placement::Surface,
 )]
 async fn COLORS(_: &Exhibit, universe: &mut Universe) {
     let gradient_resolution = 5;
@@ -801,6 +815,7 @@ async fn COLORS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Colored Lights",
     subtitle: "RGBCMY lights in an enclosed room",
+    placement: Placement::Surface,
 )]
 async fn COLOR_LIGHTS(_: &Exhibit, universe: &mut Universe) {
     let room_width = 11;
@@ -962,6 +977,7 @@ async fn COLOR_LIGHTS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "ChunkChart",
     subtitle: "Volume of world chunks in view at a distance of 4.99",
+    placement: Placement::Surface,
 )]
 async fn CHUNK_CHART(_: &Exhibit, _: &mut Universe) {
     use all_is_cubes::chunking::ChunkChart;
@@ -975,6 +991,7 @@ async fn CHUNK_CHART(_: &Exhibit, _: &mut Universe) {
 #[exhibit(
     name: "make_some_blocks()",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn MAKE_SOME_BLOCKS(_: &Exhibit, universe: &mut Universe) {
     const ROWS: GridCoordinate = 5;
@@ -1005,6 +1022,7 @@ async fn MAKE_SOME_BLOCKS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Dashed outline boxes",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn DASHED_BOXES(_: &Exhibit, universe: &mut Universe) {
     let color = Rgb::new(1.0, 0.5, 0.5);
@@ -1054,6 +1072,7 @@ async fn DASHED_BOXES(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Swimming Pool",
     subtitle: "Transparent blocks that can be passed through",
+    placement: Placement::Surface,
 )]
 async fn SWIMMING_POOL(_: &Exhibit, _: &mut Universe) {
     let width = 6;
@@ -1075,6 +1094,7 @@ async fn SWIMMING_POOL(_: &Exhibit, _: &mut Universe) {
 #[exhibit(
     name: "space_from_image()",
     subtitle: "Using rotations XYZ, XyZ, XZY, xYZ",
+    placement: Placement::Surface,
 )]
 async fn IMAGES(_: &Exhibit, universe: &mut Universe) {
     // TODO: it would be nice if this exhibit visualized the generated bounding box somehow
@@ -1119,6 +1139,7 @@ async fn IMAGES(_: &Exhibit, universe: &mut Universe) {
     name: "UI Blocks",
     subtitle:
         "Blocks from the UI system (inactive)",
+    placement: Placement::Surface,
 )]
 async fn UI_BLOCKS(_: &Exhibit, universe: &mut Universe) {
     // TODO: This was designed for a render test and is still shaped for that rather than
@@ -1183,6 +1204,7 @@ async fn UI_BLOCKS(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Trees",
     subtitle: "",
+    placement: Placement::Surface,
 )]
 async fn TREES(_: &Exhibit, universe: &mut Universe) {
     let landscape_blocks = BlockProvider::<LandscapeBlocks>::using(universe)?;
@@ -1239,6 +1261,7 @@ async fn TREES(_: &Exhibit, universe: &mut Universe) {
 #[exhibit(
     name: "Block Destruction",
     subtitle: "Animation prototype",
+    placement: Placement::Surface,
 )]
 async fn DESTRUCTION(_: &Exhibit, universe: &mut Universe) {
     let width = 7;

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

@@ -59,7 +59,7 @@ mod atrium;
 mod blocks;
 pub use blocks::*;
 mod city;
-pub(crate) use city::*;
+pub(crate) use city::demo_city;
 mod clouds;
 mod template;
 pub use template::*;