Reduce idle CPU use and prioritize compositor rendering (#62)

Avoid background title updates when no shell window list is visible, and skip output and capture invalidation for titles outside compositor decorations. Preserve focused titles, fresh window lists and capture privacy.

Request high EGL context priority with fallback, cover rendering and native title behavior in CI, and keep audio recording flowing while video capture is idle.

compositor/src/backends/direct.rs

@@ -6,6 +6,7 @@ use std::path::Path;
 use std::time::{Duration, Instant};
 
 pub(crate) mod capture;
+mod context;
 mod crtc_assignment;
 mod diagnostics;
 pub(crate) mod feedback;
@@ -29,7 +30,7 @@ use smithay::backend::allocator::{Buffer, Fourcc};
 use smithay::backend::drm::compositor::{DrmCompositor, FrameFlags, PrimaryPlaneElement};
 use smithay::backend::drm::exporter::gbm::GbmFramebufferExporter;
 use smithay::backend::drm::{DrmDevice, DrmDeviceFd, DrmEvent, DrmEventTime, DrmNode, NodeType};
-use smithay::backend::egl::{EGLContext, EGLDisplay};
+use smithay::backend::egl::EGLDisplay;
 use smithay::backend::input::InputEvent;
 use smithay::backend::libinput::{LibinputInputBackend, LibinputSessionInterface};
 use smithay::backend::renderer::element::{RenderElement, UnderlyingStorage};
@@ -1004,7 +1005,7 @@ fn open_device(state: &mut Ferese, path: &Path) -> Result<DrmNode, Box<dyn Error
     let gbm = GbmDevice::new(fd)?;
     // SAFETY: GBM owns a valid DRM descriptor for the lifetime of the EGL display.
     let egl_display = unsafe { EGLDisplay::new(gbm.clone())? };
-    let egl_context = EGLContext::new(&egl_display)?;
+    let egl_context = context::try_new(&egl_display)?;
     // SAFETY: the new context is not current on another thread and remains renderer-owned.
     let renderer = unsafe { GlesRenderer::new(egl_context)? };
     state.shm_state.update_formats(renderer.shm_formats());