Struct OffscreenSurfacePool

pub struct OffscreenSurfacePool {
    pub reuse_hits: u32,
    pub allocs: u32,
    /* private fields */
}

Frame-transient pool of offscreen render targets.

Slots persist across frames and are matched by exact PoolKey. Call Self::end_frame only after all encoded composites have finished referencing their leases. The pool has no eviction policy.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::OffscreenSurfacePool;
let pool = OffscreenSurfacePool::default();
assert_eq!((pool.reuse_hits, pool.allocs, pool.peak_bytes()), (0, 0, 0));

Fields

reuse_hits: u32

Successful exact-key lease reuses across the pool lifetime.

allocs: u32

New slot allocations across the pool lifetime.

Implementations

impl OffscreenSurfacePool

pub fn lease( &mut self, device: &Device, key: PoolKey, format: TextureFormat, ) -> LeasedOffscreen

Leases an exact-key slot, reusing a free allocation or creating one.

New textures use format, but an existing slot is keyed only by dimensions, stencil, and ping role. A pool must therefore be scoped to a single surface format. Counters use u32 and may overflow only after an impractically large number of operations.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::{OffscreenSurfacePool, PoolKey};
fn lease(pool: &mut OffscreenSurfacePool, device: &wgpu::Device) {
    let slot = pool.lease(device, PoolKey::color(64, 64, true),
        wgpu::TextureFormat::Rgba8Unorm);
    assert_eq!(slot.width, 64);
}

pub fn release(&self, lease: LeasedOffscreen)

Marks a lease’s slot free if its index exists in this pool.

Invalid or foreign indices are silently ignored. Releasing copied leases more than once is idempotent at the flag level.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::{LeasedOffscreen, OffscreenSurfacePool};
fn release(pool: &OffscreenSurfacePool, lease: LeasedOffscreen) { pool.release(lease); }

pub fn end_frame(&self)

Marks every leased slot free after the main pass has sampled offscreen textures.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::OffscreenSurfacePool;
OffscreenSurfacePool::default().end_frame();

pub fn debug_assert_leased_count(&self, expected: usize)

Debug-only: leased slot count must match active isolated passes until Self::end_frame.

Release builds compile this method as a no-op, preserving call-site shape.

Panics

Debug builds panic when the number of in-use slots differs from expected.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::OffscreenSurfacePool;
OffscreenSurfacePool::default().debug_assert_leased_count(0);

pub fn peak_bytes(&self) -> u64

Estimates peak bytes retained by all slots, including free ones.

Color and stencil each count as four bytes per pixel. This is a logical estimate and excludes row alignment, driver metadata, views, and samplers.

Examples

use ailloli_ui_render_wgpu::offscreen_pool::OffscreenSurfacePool;
assert_eq!(OffscreenSurfacePool::default().peak_bytes(), 0);

Trait Implementations

impl Default for OffscreenSurfacePool

fn default() -> OffscreenSurfacePool

Returns the “default value” for a type.