Set skybox fallback clear color

Author: DoubleStyx

crates/renderide/src/color_space.rs

@@ -1,7 +1,10 @@
-//! Shared color-space conversion helpers for host-authored values.
+//! Shared color constants and color-space conversion helpers for host-authored values.
 
 use glam::{Vec3, Vec4};
 
+/// Linear RGBA fallback color used when a skybox-backed view has no material sky to draw.
+pub(crate) const DEFAULT_SKYBOX_CLEAR_COLOR: Vec4 = Vec4::new(0.1, 0.1, 0.1, 1.0);
+
 /// Converts one sRGB channel to linear-light space.
 ///
 /// The transfer function is applied directly to the input value without clamping.

crates/renderide/src/passes/world_mesh_forward/skybox.rs

@@ -140,9 +140,9 @@ impl SkyboxRenderer {
         pipeline_state: &WorldMeshForwardPipelineState,
     ) -> Option<PreparedSkybox> {
         match frame.view.clear.mode {
-            CameraClearMode::Skybox => {
-                self.prepare_material_skybox(device, uploads, frame, pipeline_state)
-            }
+            CameraClearMode::Skybox => self
+                .prepare_material_skybox(device, uploads, frame, pipeline_state)
+                .or_else(|| self.prepare_clear_color(device, uploads, frame, pipeline_state)),
             CameraClearMode::Color => {
                 self.prepare_clear_color(device, uploads, frame, pipeline_state)
             }

crates/renderide/src/render_graph/frame_params.rs

@@ -13,6 +13,7 @@ use std::sync::Arc;
 use parking_lot::Mutex;
 
 use crate::camera::{HostCameraFrame, ViewId};
+use crate::color_space::DEFAULT_SKYBOX_CLEAR_COLOR;
 use crate::gpu::{GpuLimits, MsaaDepthResolveResources};
 use crate::materials::MaterialSystem;
 use crate::mesh_deform::{GpuSkinCache, MeshDeformScratch, MeshPreprocessPipelines};
@@ -40,7 +41,7 @@ impl FrameViewClear {
     pub fn skybox() -> Self {
         Self {
             mode: CameraClearMode::Skybox,
-            color: glam::Vec4::ZERO,
+            color: DEFAULT_SKYBOX_CLEAR_COLOR,
         }
     }
 
@@ -250,7 +251,7 @@ mod tests {
     fn main_view_clear_defaults_to_skybox() {
         let clear = FrameViewClear::default();
         assert_eq!(clear.mode, CameraClearMode::Skybox);
-        assert_eq!(clear.color, glam::Vec4::ZERO);
+        assert_eq!(clear.color, glam::Vec4::new(0.1, 0.1, 0.1, 1.0));
     }
 
     #[test]

crates/renderide/src/scene/coordinator.rs

@@ -9,6 +9,7 @@ use std::collections::HashSet;
 use glam::Mat4;
 
 use crate::assets::texture::{HostTextureAssetKind, pack_host_texture_id};
+use crate::color_space::DEFAULT_SKYBOX_CLEAR_COLOR;
 use crate::ipc::SharedMemoryAccessor;
 use crate::shared::{
     BlitToDisplayState, FrameSubmitData, RenderSH2, RenderSpaceUpdate, RenderingContext,
@@ -372,7 +373,7 @@ impl SceneCoordinator {
         Some(BlitToDisplayState {
             renderable_index: -1,
             texture_id: packed_texture_id,
-            background_color: glam::Vec4::new(0.0, 0.0, 0.0, 1.0),
+            background_color: DEFAULT_SKYBOX_CLEAR_COLOR,
             display_index: PRIMARY_DESKTOP_DISPLAY_INDEX,
             flags: 0,
             _padding: [0; 1],

crates/renderide/src/scene/coordinator/tests/queries.rs

@@ -5,6 +5,7 @@
 use glam::{Mat4, Quat, Vec3};
 
 use crate::camera::{view_matrix_for_world_mesh_render_space, view_matrix_from_render_transform};
+use crate::color_space::DEFAULT_SKYBOX_CLEAR_COLOR;
 use crate::scene::CameraRenderableEntry;
 use crate::scene::blit_to_display::BlitToDisplayEntry;
 use crate::scene::overrides::RenderTransformOverrideEntry;
@@ -227,6 +228,41 @@ fn active_blit_for_display_ignores_overlay_dash_camera() {
     assert!(scene.active_blit_for_display(1).is_none());
 }
 
+#[test]
+fn desktop_blit_for_display_uses_skybox_clear_for_synthesized_dash_blit() {
+    let mut scene = SceneCoordinator::new();
+    let overlay = RenderSpaceId(3);
+    scene.spaces.insert(
+        overlay,
+        RenderSpaceState {
+            id: overlay,
+            is_active: true,
+            is_overlay: true,
+            cameras: vec![CameraRenderableEntry {
+                renderable_index: 0,
+                transform_id: 0,
+                state: CameraState {
+                    projection: CameraProjection::Orthographic,
+                    render_texture_asset_id: 77,
+                    selective_render_count: 1,
+                    flags: 1,
+                    ..Default::default()
+                },
+                selective_transform_ids: vec![5],
+                exclude_transform_ids: Vec::new(),
+            }],
+            ..Default::default()
+        },
+    );
+
+    let state = scene
+        .desktop_blit_for_display(0)
+        .expect("primary desktop display should synthesize dashboard blit");
+
+    assert_eq!(state.background_color, DEFAULT_SKYBOX_CLEAR_COLOR);
+    assert!(scene.desktop_blit_for_display(1).is_none());
+}
+
 #[test]
 fn world_matrix_excludes_render_space_root() {
     let mut scene = SceneCoordinator::new();