Gfx::RhiPreviewWidget Class Reference

A QWidget that paints a score::gfx render-graph output without using QWidget::createWindowContainer (broken on macOS) or QRhiWidget (forces the toplevel to switch to RHI compositing — flash + perf impact). More...

Inheritance diagram for Gfx::RhiPreviewWidget:

Detailed Description

A QWidget that paints a score::gfx render-graph output without using QWidget::createWindowContainer (broken on macOS) or QRhiWidget (forces the toplevel to switch to RHI compositing — flash + perf impact).

The graph renders into an offscreen QRhi texture owned by a score::gfx::BackgroundNode; each frame is read back into a QImage-shaped QByteArray and drawn in paintEvent. CPU readback is cheap at preview resolutions and avoids touching Qt's compositor RHI entirely.

Two backends:

• Graph backend (useGraph): caller owns a score::gfx::Graph and drives wiring through callbacks. Used by ShaderPreviewManager.
• Context backend (useContext): caller routes registration through a Gfx::GfxContext. The GfxContext's manual timer drives the offscreen render; the widget only triggers QWidget::update() to refresh the painted image. Used by GraphPreviewWidget (texture-port preview).

Public Member Functions
	RhiPreviewWidget (QWidget *parent=nullptr)
void	useGraph (score::gfx::Graph *graph, std::function< void(score::gfx::BackgroundNode &)> onAttached, std::function< void(score::gfx::BackgroundNode &)> onAboutToDetach)
void	useContext (GfxContext *ctx, port_index producer)
void	setProducer (port_index producer)

Protected Member Functions
void	paintEvent (QPaintEvent *ev) override
void	resizeEvent (QResizeEvent *ev) override
void	timerEvent (QTimerEvent *ev) override

Member Function Documentation

useContext()

void Gfx::RhiPreviewWidget::useContext	(	GfxContext *	ctx,
		port_index	producer
	)

Context backend. The producer endpoint can be updated at any time; the widget rewires the preview edge accordingly. It is a (node, port) pair, not just a node: a process whose texture outlet is not its first outlet registers under that outlet's own index.

useGraph()

void Gfx::RhiPreviewWidget::useGraph	(	score::gfx::Graph *	graph,
		std::function< void(score::gfx::BackgroundNode &)>	onAttached,
		std::function< void(score::gfx::BackgroundNode &)>	onAboutToDetach
	)

Graph backend. onAttached fires once the BackgroundNode has been registered with the graph (its render list is built). The caller wires producer→preview edges in there. onAboutToDetach fires before the BackgroundNode is removed; the caller must remove any edges it added.

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The documentation for this class was generated from the following files:

• RhiPreviewWidget.hpp
• RhiPreviewWidget.cpp