Allow changing the created skybox size when using detection (#76)

Author: ptsd

src/lib.rs

@@ -52,13 +52,28 @@
 //!
 //! Use the [`AtmosphereSettings`](crate::settings::AtmosphereSettings) resource to change how the sky is rendered.
 //! ```no_run
-//! # use bevy_atmosphere::settings::AtmosphereSettings;
+//! # use bevy::utils::default;
+//! use bevy_atmosphere::settings::AtmosphereSettings;
 //! # let _ =
 //! AtmosphereSettings {
 //!     // changes the resolution (should be a multiple of 8)
 //!     resolution: 1024,
 //!     // turns off dithering
 //!     dithering: false,
+//!     ..default()
+//! }
+//! # ;
+//! ```
+//!
+//! When using the `detection` feature, you can use [`SkyboxCreationMode`](crate::settings::SkyboxCreationMode) to control the size of the generated skybox.
+//! ```no_run
+//! # use bevy::utils::default;
+//! use bevy_atmosphere::settings::{AtmosphereSettings, SkyboxCreationMode};
+//! # let _ =
+//! AtmosphereSettings {
+//!     // Will use the camera projections `far` value or `1000.0` as a fallback
+//!     skybox_creation_mode: SkyboxCreationMode::FromProjectionFarWithFallback(1000.0),
+//!     ..default()
 //! }
 //! # ;
 //! ```

src/plugin.rs

@@ -14,9 +14,13 @@ use bevy::{
 use crate::{
     model::AddAtmosphereModel,
     pipeline::*,
+    settings::AtmosphereSettings,
     skybox::{AtmosphereSkyBoxMaterial, SkyBoxMaterial, ATMOSPHERE_SKYBOX_SHADER_HANDLE},
 };
 
+#[cfg(feature = "detection")]
+use crate::settings::SkyboxCreationMode;
+
 /// A `Plugin` that adds the prerequisites for a procedural sky.
 #[derive(Debug, Clone, Copy)]
 pub struct AtmospherePlugin;
@@ -101,17 +105,29 @@ pub struct AtmosphereSkyBox;
 fn atmosphere_insert(
     mut commands: Commands,
     mut mesh_assets: ResMut<Assets<Mesh>>,
+    settings: Res<AtmosphereSettings>,
     material: Res<AtmosphereSkyBoxMaterial>,
     atmosphere_cameras: Query<(Entity, &Projection, &AtmosphereCamera), Added<AtmosphereCamera>>,
 ) {
     for (camera, projection, atmosphere_camera) in &atmosphere_cameras {
-        trace!("Adding skybox to camera entity (ID:{:?})", camera);
+        let far_size = match settings.skybox_creation_mode {
+            // TODO: Use `unwrap_or(fallback)` when `projection.far()` becomes an `Option<f32>`
+            SkyboxCreationMode::FromProjectionFarWithFallback(_fallback) => projection.far(),
+            SkyboxCreationMode::FromSpecifiedFar(specified) => specified,
+        };
+
+        trace!(
+            "Adding skybox to camera entity (ID:{:?}) with far_size {}",
+            camera,
+            far_size
+        );
+
         commands
             .entity(camera)
             .insert(Visibility::Visible)
             .with_children(|c| {
                 let mut child = c.spawn((
-                    Mesh3d(mesh_assets.add(crate::skybox::mesh(projection.far()))),
+                    Mesh3d(mesh_assets.add(crate::skybox::mesh(far_size))),
                     MeshMaterial3d(material.0.clone()),
                     AtmosphereSkyBox,
                     NotShadowCaster,

src/settings.rs

@@ -2,6 +2,23 @@
 
 use bevy::{prelude::Resource, render::extract_resource::ExtractResource};
 
+/// Available methods for determining the size of the auto created skybox
+#[cfg(feature = "detection")]
+#[derive(Debug, Clone, Copy)]
+pub enum SkyboxCreationMode {
+    /// Uses the camera projection `far` value or the specified fallback if `far` is `None`.
+    FromProjectionFarWithFallback(f32),
+    /// Ignores any camera projection `far` value and always uses the specified value.
+    FromSpecifiedFar(f32),
+}
+
+#[cfg(feature = "detection")]
+impl Default for SkyboxCreationMode {
+    fn default() -> Self {
+        Self::FromProjectionFarWithFallback(1000.0)
+    }
+}
+
 /// Provides settings for how the sky is rendered.
 #[derive(Resource, ExtractResource, Debug, Clone, Copy)]
 pub struct AtmosphereSettings {
@@ -16,6 +33,13 @@ pub struct AtmosphereSettings {
     /// This option can be removed by disabling the "dithering" feature
     #[cfg(feature = "dithering")]
     pub dithering: bool,
+    /// Method used to determine the size of the auto created skybox.
+    ///
+    /// See [`SkyboxCreationMode`]
+    ///
+    /// Default: `FromProjectionFarWithFallback(1000.0)`.
+    #[cfg(feature = "detection")]
+    pub skybox_creation_mode: SkyboxCreationMode,
 }
 
 impl Default for AtmosphereSettings {
@@ -24,6 +48,8 @@ impl Default for AtmosphereSettings {
             resolution: 512,
             #[cfg(feature = "dithering")]
             dithering: true,
+            #[cfg(feature = "detection")]
+            skybox_creation_mode: SkyboxCreationMode::default(),
         }
     }
 }