AsyncRenderer owns a svg::Renderer and runs compositor rendering plus any final presentation snapshot handoff on a dedicated worker thread so heavy renders don't block the UI thread. More...

#include <atomic>
#include <chrono>
#include <condition_variable>
#include <cstdint>
#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <string>
#include <thread>
#include <unordered_map>
#include <variant>
#include <vector>
#include "donner/base/EcsRegistry.h"
#include "donner/base/Transform.h"
#include "donner/base/Vector2.h"
#include "donner/editor/ViewportState.h"
#include "donner/svg/SVGDocument.h"
#include "donner/svg/SVGElement.h"
#include "donner/svg/compositor/CompositorController.h"
#include "donner/svg/compositor/ScopedCompositorHint.h"
#include "donner/svg/renderer/Renderer.h"
#include "donner/svg/renderer/RendererInterface.h"

Include dependency graph for AsyncRenderer.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	donner::editor::RenderLease
	Non-null renderer/document handoff for a render request. More...
struct	donner::editor::RenderRequest
	Per-request handoff data captured at render-request time so the worker has everything it needs without touching live UI state. More...
struct	donner::editor::RenderRequest::DragPreview
struct	donner::editor::PresentationSnapshotPlan
	Final full-canvas snapshot work needed after compositor rendering. More...
struct	donner::editor::RenderResult
	Presentation payload plus the document version it was rendered from. More...
struct	donner::editor::RenderResult::WorkerTimingBreakdown
	Internal timing split for one async worker iteration. More...
struct	donner::editor::RenderResult::CompositedTile
	One composite tile from the worker's CompositorController:: snapshotCompositorTiles() snapshot (design doc 0033 §M2C). The editor uploads one GL texture per tile (keyed on id) and blits each tile at its canvas offset. Immediate tiles intentionally use transient ids and always carry a fresh payload. Geometry fields are doc-unit quantities so the editor can scale them by the current pixelsPerDocUnit during canvas-resize debouncing. More...
struct	donner::editor::RenderResult::CompositedPreview
class	donner::editor::AsyncRenderer

Namespaces
namespace	donner
	Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css.
namespace	donner::svg
	Donner SVG library, which can load, manipulate and render SVG files.

Functions
PresentationSnapshotPlan	donner::editor::ChoosePresentationSnapshotPlan (bool hasCompositedPreview, bool requiresTextureSnapshotPresentation)
	Choose final full-canvas snapshot work for a render result.

Detailed Description

AsyncRenderer owns a svg::Renderer and runs compositor rendering plus any final presentation snapshot handoff on a dedicated worker thread so heavy renders don't block the UI thread.

Threading model

The worker thread owns the Renderer for its entire lifetime. Backends with thread-affined GPU objects depend on device, pipeline, texture, and readback use staying on that thread.

The worker additionally takes exclusive ownership of the SVGDocument during an active render. The UI thread must not mutate the document while a render is in flight.

UI thread flow per frame:

pollResult() — if a render just finished, pick up the bitmap.
If NOT busy: process mutations via flushFrame().
If NOT busy AND a new render is needed: requestRender().
If busy: skip flushFrame, leave pending mutations in the queue. They apply on the next idle frame. Input (drags, typing) still gets processed and queued — just not dispatched to the ECS.
The editor overlay is the exception: it may take guarded document access for immediate presentation chrome. That access serializes behind the worker's render access instead of racing it, and must not be taken while holding AsyncRenderer's mutex.

The safety invariant: between requestRender() and a non-nullopt return from pollResult(), the UI thread must not mutate the SVGDocument. Registry-reading UI paths should normally gate on !isBusy() unless they are using guarded access for immediate overlay presentation. The UI thread must not call any method on the worker Renderer at any time — it lives on the worker.

Class Documentation

◆ donner::editor::RenderRequest::DragPreview

struct donner::editor::RenderRequest::DragPreview

Collaboration diagram for donner::editor::RenderRequest::DragPreview:

[legend]

Class Members
Transform2d	documentFromCachedDocument = Transform2d()	Active affine transform represented by this request. Selection prewarms use identity.
uint64_t	dragGeneration = 0	Monotonic id for the active drag gesture. Selection prewarms use zero.
Entity	entity = entt::null
vector< Entity >	extraEntities	Additional entities moving with entity under the same active drag transform.
InteractionHint	interactionKind = svg::compositor::InteractionHint::ActiveDrag	Which interaction phase drove this preview. Selection means the editor is pre-warming a layer for the selected entity before any drag begins. ActiveDrag means the user is actively dragging — the DOM's transform attribute already reflects the cursor delta. The compositor stamps the correct InteractionHint on the entity based on this field so downstream introspection stays accurate.
Vector2d	translation = Vector2d::Zero()	Active drag translation represented by this request. Selection prewarms use zero.

◆ donner::editor::RenderResult::WorkerTimingBreakdown

struct donner::editor::RenderResult::WorkerTimingBreakdown

Internal timing split for one async worker iteration.

Class Members
double	buildPreviewMs = 0.0	Time spent building composited-preview tile metadata/payloads.
double	diagnosticsMs = 0.0	Time spent copying compositor diagnostics for editor panels.
double	finalSnapshotMs = 0.0	Time spent taking the final fallback canvas snapshot, when needed.
double	renderFrameMs = 0.0	Time spent in CompositorController::renderFrame.
double	setupMs = 0.0	Time before CompositorController::renderFrame, including compositor selection setup.

Function Documentation

◆ ChoosePresentationSnapshotPlan()

PresentationSnapshotPlan donner::editor::ChoosePresentationSnapshotPlan	(	bool	hasCompositedPreview,
		bool	requiresTextureSnapshotPresentation )

nodiscard

Choose final full-canvas snapshot work for a render result.

Parameters

hasCompositedPreview	True when compositor tiles already provide the presented pixels.
requiresTextureSnapshotPresentation	True when presentation must remain on GPU textures.

Returns: The final snapshot plan for this worker iteration.

Classes

Namespaces