Refactor Studio entry-points (#54)

This PR heavily refactors the entry-point functions in
`studio/src/lib.rs` to simplify and consolidate. Additionally, the
frontend application should now be configurable as expected with any
valid combination of the following URL parameters:

* `objectId` : A pre-bundled library object to load (e.g., "couch.gltf")
* `bvh` : Any resolvable path to a BVH animation with a MocapNET
skeleton (e.g., "mocap/shuffle.bvh")
* `mixamo` : Any resolvable path to a glTF animation with the Mixamo
skeleton (e.g., "mocap/hip-hop-dancing.gltf")
* `sceneImport` : Any resolvable path to an arbitrary glTF scene
(untested, but should theoretically work)
* `scene` : Any resolvable path to a previously saved Storyteller Studio
scene in `*.scn.ron` format
* `skybox` : The ID of a pre-bundled skybox asset. Valid options are:
  - "gum_trees_4k"
  - "kloofenfal_28d_misty_4k"
  - "meadow_4k"
  - "promenade_de_vidy_4k"
  - "scythian_tombs_4k"
  - "test_scene" (this is the default if not specified)
* `mode` : One of "studio" or "viewer" (the default if not specified)

"Validity" rules are as follows:

* `objectId`, `bvh`, `mixamo`, `sceneImport` and `scene` are mutually
exclusive
* `skybox` is not supported for `scene` (the skybox should be saved and
loaded as part of the scene description, though this is not currently
working)
* Both `mode` options are valid for all other parameters

studio/src/wasm/init.rs

@@ -0,0 +1,164 @@
+use bevy::prelude::*;
+use serde::{Deserialize, Serialize};
+use wasm_bindgen::prelude::*;
+
+use crate::{InitAsset, InitParams, StudioMode, ViewportSize};
+
+#[wasm_bindgen(typescript_custom_section)]
+const WASM_ENTRY_POINTS: &str = r#"
+export type SkyboxId
+    = "gum_trees_4k"
+    | "kloofenfal_28d_misty_4k"
+    | "meadow_4k"
+    | "promenade_de_vidy_4k"
+    | "scythian_tombs_4k"
+    | "test_scene"
+    ;
+
+export interface InitOptions {
+    mode: StudioMode;
+    /** Required for all entry-points except `initFromStorytellerScene()` */
+    skyboxId?: SkyboxId;
+    canvasSelector: string;
+    canvasAlt: string;
+    viewportSize: ViewportSize;
+}
+
+export function initFromLibrary(objectId: string, options: InitOptions): void;
+export function initFromBvh(animPath: string, options: InitOptions): void;
+export function initFromMixamo(animPath: string, options: InitOptions): void;
+export function initFromSceneImport(scenePath: string, options: InitOptions): void;
+export function initFromStorytellerScene(scenePath: string, options: InitOptions): void;
+"#;
+
+#[derive(Serialize, Deserialize)]
+struct WasmInitOptions {
+    #[serde(rename = "skyboxId")]
+    skybox_id: Option<String>,
+    mode: StudioMode,
+    #[serde(rename = "canvasSelector")]
+    canvas_selector: String,
+    #[serde(rename = "canvasAlt")]
+    canvas_alt: String,
+    #[serde(rename = "viewportSize")]
+    viewport_size: ViewportSize,
+}
+
+#[wasm_bindgen(skip_typescript, js_name = initFromLibrary)]
+pub fn init_from_library(object_id: String, options: JsValue) -> Result<(), JsValue> {
+    let options = serde_wasm_bindgen::from_value::<WasmInitOptions>(options)?;
+    let skybox_id = options
+        .skybox_id
+        .expect("`skyboxId` is required for `initFromLibrary`");
+
+    crate::start(
+        InitParams::FromAsset {
+            asset: InitAsset::LibraryObject(object_id),
+            skybox_id,
+        },
+        options.mode,
+        Some(Window {
+            resolution: options.viewport_size.into(),
+            title: options.canvas_alt,
+            canvas: Some(options.canvas_selector),
+            ..default()
+        }),
+    )
+    .run();
+
+    Ok(())
+}
+
+#[wasm_bindgen(skip_typescript, js_name = initFromBvh)]
+pub fn init_from_bvh(anim_path: String, options: JsValue) -> Result<(), JsValue> {
+    let options = serde_wasm_bindgen::from_value::<WasmInitOptions>(options)?;
+    let skybox_id = options
+        .skybox_id
+        .expect("`skyboxId` is required for `initFromBvh`");
+
+    crate::start(
+        InitParams::FromAsset {
+            asset: InitAsset::BvhAnim(anim_path),
+            skybox_id,
+        },
+        options.mode,
+        Some(Window {
+            resolution: options.viewport_size.into(),
+            title: options.canvas_alt,
+            canvas: Some(options.canvas_selector),
+            ..default()
+        }),
+    )
+    .run();
+
+    Ok(())
+}
+
+#[wasm_bindgen(skip_typescript, js_name = initFromMixamo)]
+pub fn init_from_mixamo(anim_path: String, options: JsValue) -> Result<(), JsValue> {
+    let options = serde_wasm_bindgen::from_value::<WasmInitOptions>(options)?;
+    let skybox_id = options
+        .skybox_id
+        .expect("`skyboxId` is required for `initFromMixamo`");
+
+    crate::start(
+        InitParams::FromAsset {
+            asset: InitAsset::MixamoAnim(anim_path),
+            skybox_id,
+        },
+        options.mode,
+        Some(Window {
+            resolution: options.viewport_size.into(),
+            title: options.canvas_alt,
+            canvas: Some(options.canvas_selector),
+            ..default()
+        }),
+    )
+    .run();
+
+    Ok(())
+}
+
+#[wasm_bindgen(skip_typescript, js_name = initFromSceneImport)]
+pub fn init_from_scene_import(scene_path: String, options: JsValue) -> Result<(), JsValue> {
+    let options = serde_wasm_bindgen::from_value::<WasmInitOptions>(options)?;
+    let skybox_id = options
+        .skybox_id
+        .expect("`skyboxId` is required for `initFromSceneImport`");
+
+    crate::start(
+        InitParams::FromAsset {
+            asset: InitAsset::ImportedScene(scene_path),
+            skybox_id,
+        },
+        options.mode,
+        Some(Window {
+            resolution: options.viewport_size.into(),
+            title: options.canvas_alt,
+            canvas: Some(options.canvas_selector),
+            ..default()
+        }),
+    )
+    .run();
+
+    Ok(())
+}
+
+#[wasm_bindgen(skip_typescript, js_name = initFromStorytellerScene)]
+pub fn init_from_storyteller_scene(scene_path: String, options: JsValue) -> Result<(), JsValue> {
+    let options = serde_wasm_bindgen::from_value::<WasmInitOptions>(options)?;
+
+    crate::start(
+        InitParams::FromScene(scene_path),
+        options.mode,
+        Some(Window {
+            resolution: options.viewport_size.into(),
+            title: options.canvas_alt,
+            canvas: Some(options.canvas_selector),
+            ..default()
+        }),
+    )
+    .run();
+
+    Ok(())
+}

studio/src/wasm/mod.rs

@@ -4,6 +4,7 @@ use parking_lot::ReentrantMutex;
 use wasm_bindgen::prelude::wasm_bindgen;
 
 mod conv;
+mod init;
 #[cfg(feature = "wasm_screenshot")]
 mod screenshot;
 mod util;