Let m toggle between map_esdf and map_wasd.

Author: n3vu0r

src/controller.rs

@@ -37,6 +37,23 @@ pub struct TrackballController {
 	first_count: usize,
 }
 
+impl TrackballController {
+	/// Trackball controller using [`TrackballInput::map_esdf`].
+	#[must_use]
+	pub fn map_esdf() -> Self {
+		let mut controller = Self::default();
+		controller.input.map_esdf();
+		controller
+	}
+	/// Trackball controller using [`TrackballInput::map_wasd`].
+	#[must_use]
+	pub fn map_wasd() -> Self {
+		let mut controller = Self::default();
+		controller.input.map_wasd();
+		controller
+	}
+}
+
 #[allow(clippy::needless_pass_by_value)]
 #[allow(clippy::too_many_arguments)]
 pub fn trackball_controller(

src/controller/input.rs

@@ -19,6 +19,8 @@ pub struct TrackballInput {
 	/// the focus operation in favor of the orbit operation.
 	pub focus: bool,
 
+	/// Key used to toggle `esdf`/`wasd` mapping. Default is [`KeyCode::M`].
+	pub gamer_key: Option<KeyCode>,
 	/// Key used to toggle projection mode. Default is [`KeyCode::P`].
 	pub ortho_key: Option<KeyCode>,
 
@@ -74,6 +76,51 @@ pub struct TrackballInput {
 	pub scale_out_key: Option<KeyCode>,
 }
 
+impl TrackballInput {
+	/// Maps `esdf`/`gv` to slide operations.
+	///
+	/// Key | Operation
+	/// --- | ---------------------------
+	/// `e` | Slides up.
+	/// `s` | Slides left.
+	/// `d` | Slides down.
+	/// `f` | Slides right.
+	/// `g` | Slides far (in/forward).
+	/// `v` | Slides near (out/backward).
+	///
+	/// This mapping is symmetric to the `ijkl`/`hn` orbit mapping but less intuitive to gamers
+	/// compared with [`Self::map_wasd`].
+	pub fn map_esdf(&mut self) {
+		self.slide_up_key = Some(KeyCode::E);
+		self.slide_down_key = Some(KeyCode::D);
+		self.slide_left_key = Some(KeyCode::S);
+		self.slide_right_key = Some(KeyCode::F);
+		self.slide_far_key = Some(KeyCode::G);
+		self.slide_near_key = Some(KeyCode::V);
+	}
+	/// Maps `wasd`/`Space`/`ControlLeft` to slide operations.
+	///
+	/// Key           | Operation
+	/// ------------- | ---------------------------
+	/// `w`           | Slides far (in/forward).
+	/// `a`           | Slides left.
+	/// `s`           | Slides near (out/backward).
+	/// `d`           | Slides right.
+	/// `Space`       | Slides up (jump).
+	/// `ControlLeft` | Slides down (crouch).
+	///
+	/// This mapping isn't symmetric to the `ijkl`/`hn` orbit mapping but more intuitive to gamers
+	/// compared with [`Self::map_esdf`].
+	pub fn map_wasd(&mut self) {
+		self.slide_up_key = Some(KeyCode::Space);
+		self.slide_down_key = Some(KeyCode::ControlLeft);
+		self.slide_left_key = Some(KeyCode::A);
+		self.slide_right_key = Some(KeyCode::D);
+		self.slide_far_key = Some(KeyCode::W);
+		self.slide_near_key = Some(KeyCode::S);
+	}
+}
+
 impl Default for TrackballInput {
 	fn default() -> Self {
 		Self {
@@ -82,6 +129,8 @@ impl Default for TrackballInput {
 
 			focus: true,
 
+			gamer_key: Some(KeyCode::M),
+
 			ortho_key: Some(KeyCode::P),
 
 			reset_key: Some(KeyCode::Return),

src/controller/key.rs

@@ -4,6 +4,7 @@ use trackball::nalgebra::{Point3, Unit, UnitQuaternion};
 use crate::{TrackballCamera, TrackballController, TrackballEvent};
 
 #[allow(clippy::too_many_arguments)]
+#[allow(clippy::too_many_lines)]
 pub fn key(
 	group: Entity,
 	trackball_events: &mut EventWriter<TrackballEvent>,
@@ -29,6 +30,13 @@ pub fn key(
 	if just_pressed(controller.input.ortho_key) {
 		trackball_events.send(TrackballEvent::ortho(group, None));
 	}
+	if just_pressed(controller.input.gamer_key) {
+		if controller.input.slide_far_key == Some(KeyCode::W) {
+			controller.input.map_esdf();
+		} else {
+			controller.input.map_wasd();
+		}
+	}
 	for (key, vec) in [
 		(controller.input.slide_far_key, Vec3::NEG_Z),
 		(controller.input.slide_near_key, Vec3::Z),

src/lib.rs

@@ -5,6 +5,14 @@
 //! [WebAssembly]: https://en.wikipedia.org/wiki/WebAssembly
 //! [WebGL]: https://en.wikipedia.org/wiki/WebGL
 //!
+//! # Camera Modes
+//!
+//! Supports multiple camera modes:
+//!
+//!   * Trackball mode rotates camera around target.
+//!   * First-Person mode rotates target around camera.
+//!   * Spectator mode translates target and camera.
+//!
 //! # Coherence Features
 //!
 //! This is an alternative trackball technique using exponential map and parallel transport to
@@ -22,7 +30,7 @@
 //!   * Coherent and intuitive orbiting via the exponential map, see the underlying [`trackball`]
 //!     crate which follows the recipe given in the paper of Stantchev, G.. “Virtual Trackball
 //!     Modeling and the Exponential Map.”. [S2CID] [44199608]. See the [`exponential_map`] example.
-//!   * Coherent first person view aka free look or mouse look with the world trackball centered at
+//!   * Coherent first-person mode aka free look or mouse look with the world trackball centered at
 //!     eye instead of target.
 //!   * Coherent scaling by translating mouse wheel device units, see [`TrackballWheelUnit`]. Scales
 //!     eye distance from current cursor position or centroid of finger positions projected onto
@@ -76,14 +84,18 @@
 //! ----------------------- | ----------------------- | -------- | ---------------------------------
 //! Left Press + Drag       | One + Drag              | `ijkl`   | Orbits around target.
 //! ↳ at trackball's border | Two + Roll              | `uo`     | Rolls about view direction.
-//! Middle Press + Drag     | Any + Drag + Left Shift | `↑←↓→`   | First person view.
+//! Middle Press + Drag     | Any + Drag + Left Shift | `↑←↓→`   | First-person mode.
 //! Right Press + Drag      | Two + Drag              | `esdf`   | Slides trackball on focus plane.
 //!                    |                    | `gv`     | Slides trackball in/out.
 //! Scroll In/Out           | Two + Pinch Out/In      | `hn`     | Scales distance zooming in/out.
 //! Left Press + Release    | Any + Release           |     | Slides to cursor/finger position.
+//!                    |                    | `m`      | Toggle `esdf`/`wasd` mapping.
 //!                    |                    | `p`      | Toggle orthographic/perspective.
 //!                    |                    | `Return` | Reset camera transform.
 //!
+//! Alternatively, [`TrackballInput::map_wasd`] maps `wasd`/`Space`/`ControlLeft` to slide
+//! operations where `wd` slides in/out and `Space`/`ControlLeft` slides up/down (jump/crouch).
+//!
 //! # Usage
 //!
 //! Add the [`TrackballPlugin`] followed by spawning a [`TrackballController`] together with a