donner::svg::Renderer Class Reference

Backend-agnostic renderer that resolves to the active build backend (Skia or tiny-skia). More...

#include "donner/svg/renderer/Renderer.h"

Inheritance diagram for donner::svg::Renderer:

Public Member Functions
	Renderer (bool verbose=false)
	Creates a renderer for the active backend.
	Renderer (std::shared_ptr< geode::GeodeDevice > device, bool verbose=false)
	Creates a renderer for the active backend using an externally-owned Geode device when the Geode backend is selected.
	~Renderer () override
	Destructor.
	Renderer (Renderer &&) noexcept
	Move constructor.
Renderer &	operator= (Renderer &&) noexcept
	Move assignment operator.
	Renderer (const Renderer &)=delete
Renderer &	operator= (const Renderer &)=delete
void	draw (SVGDocument &document) override
	Draws the SVG document using the active backend.
RendererBitmap	renderElementToBitmap (SVGElement element, Vector2i sizePx)
	Rasterize a single SVGElement and its descendant subtree to an RGBA bitmap fitted into a target box.
void	beginFrame (const RenderViewport &viewport) override
	Begins a render pass for the given viewport.
void	endFrame () override
	Completes the current render pass.
void	setTransform (const Transform2d &transform) override
	Sets the absolute transform, replacing the current matrix.
void	pushTransform (const Transform2d &transform) override
	Pushes a relative transform.
void	popTransform () override
	Pops the most recent transform.
void	pushClip (const ResolvedClip &clip) override
	Pushes a clip rect or clip path.
void	popClip () override
	Pops the most recent clip.
void	pushIsolatedLayer (double opacity, MixBlendMode blendMode) override
	Pushes an isolated compositing layer.
void	popIsolatedLayer () override
	Pops the most recent isolated layer.
void	pushFilterLayer (const components::FilterGraph &filterGraph, const std::optional< Box2d > &filterRegion) override
	Pushes a filter layer.
void	popFilterLayer () override
	Pops the most recent filter layer.
void	pushMask (const std::optional< Box2d > &maskBounds) override
	Begins mask rendering.
void	transitionMaskToContent () override
	Switches from mask rendering to masked content rendering.
void	popMask () override
	Pops the current mask and composites the masked content.
bool	beginPatternTile (const Box2d &tileRect, const Transform2d &targetFromPattern) override
	Begins pattern tile recording.
void	endPatternTile (bool forStroke) override
	Ends pattern recording and stores the resulting pattern paint.
void	setPaint (const PaintParams &paint) override
	Sets the active paint parameters for subsequent draw calls.
void	drawPath (const PathShape &path, const StrokeParams &stroke) override
	Draws an arbitrary path.
void	drawRect (const Box2d &rect, const StrokeParams &stroke) override
	Draws an axis-aligned rectangle.
void	drawEllipse (const Box2d &bounds, const StrokeParams &stroke) override
	Draws an ellipse.
void	drawImage (const ImageResource &image, const ImageParams &params) override
	Draws an image resource.
void	drawBitmap (const RendererBitmap &bitmap, const ImageParams &params) override
	Draws a CPU-readable bitmap into the given target rectangle.
bool	drawTextureSnapshot (const RendererTextureSnapshot &texture, const Box2d &targetRect, double opacity=1.0, bool pixelated=false) override
	Draws a backend-owned texture snapshot when the active backend supports it.
void	drawText (Registry &registry, const components::ComputedTextComponent &text, const TextParams &params) override
	Draws shaped text.
RendererBitmap	takeSnapshot () const override
	Captures a CPU-readable snapshot of the current frame.
std::shared_ptr< const RendererTextureSnapshot >	takeTextureSnapshot () override
	Captures a backend-owned GPU texture snapshot when the active backend supports it.
bool	requiresTextureSnapshotPresentation () const override
	Returns true when this backend requires direct texture presentation.
std::unique_ptr< RendererInterface >	createOffscreenInstance () const override
	Creates an offscreen renderer of the active backend type.
void	setDebugGeometryOverlay (bool enabled) override
	Forwards RendererInterface::setDebugGeometryOverlay to the active backend (no-op for backends without a debug overlay).
bool	debugGeometryOverlay () const override
	Whether the active backend's geometry debug overlay is enabled.
bool	save (const char *filename)
	Saves the last rendered frame to a PNG file.
int	width () const override
	Returns the rendered width in pixels.
int	height () const override
	Returns the rendered height in pixels.

Detailed Description

Backend-agnostic renderer that resolves to the active build backend (Skia or tiny-skia).

Typical usage:

Renderer renderer;
renderer.draw(document);
renderer.save("output.png");

The draw() method handles the full rendering pipeline internally: computing styles, building the render tree, and rasterizing. For frame-based rendering (e.g., in a viewer), use beginFrame() / endFrame() directly via the RendererInterface API.

Constructor & Destructor Documentation

Renderer() [1/2]

donner::svg::Renderer::Renderer ( bool verbose = false )

explicit

Creates a renderer for the active backend.

Parameters

verbose

If true, enables backend-specific verbose logging.

Renderer() [2/2]

donner::svg::Renderer::Renderer ( std::shared_ptr< geode::GeodeDevice > device, bool verbose = false )

explicit

Creates a renderer for the active backend using an externally-owned Geode device when the Geode backend is selected.

Non-Geode backends ignore device and construct their normal backend.

Parameters

device	Shared Geode device.
verbose	If true, enables backend-specific verbose logging.

Member Function Documentation

beginFrame()

void donner::svg::Renderer::beginFrame ( const RenderViewport & viewport )

overridevirtual

Begins a render pass for the given viewport.

Parameters

viewport

The viewport dimensions for the render pass.

Implements donner::svg::RendererInterface.

beginPatternTile()

bool donner::svg::Renderer::beginPatternTile ( const Box2d & tileRect, const Transform2d & targetFromPattern )

nodiscardoverridevirtual

Begins pattern tile recording.

Parameters

tileRect	Tile bounds in pattern space.
targetFromPattern	Transform from pattern tile space to target space.

Implements donner::svg::RendererInterface.

createOffscreenInstance()

std::unique_ptr< RendererInterface > donner::svg::Renderer::createOffscreenInstance ( ) const

nodiscardoverridevirtual

Creates an offscreen renderer of the active backend type.

Reimplemented from donner::svg::RendererInterface.

debugGeometryOverlay()

bool donner::svg::Renderer::debugGeometryOverlay ( ) const

nodiscardoverridevirtual

Whether the active backend's geometry debug overlay is enabled.

Reimplemented from donner::svg::RendererInterface.

draw()

void donner::svg::Renderer::draw ( SVGDocument & document )

overridevirtual

Draws the SVG document using the active backend.

Parameters

document

The SVG document to render.

Implements donner::svg::RendererInterface.

drawBitmap()

void donner::svg::Renderer::drawBitmap ( const RendererBitmap & bitmap, const ImageParams & params )

overridevirtual

Draws a CPU-readable bitmap into the given target rectangle.

Parameters

bitmap	The bitmap to draw.
params	Image placement parameters.

Reimplemented from donner::svg::RendererInterface.

drawEllipse()

void donner::svg::Renderer::drawEllipse ( const Box2d & bounds, const StrokeParams & stroke )

overridevirtual

Draws an ellipse.

Parameters

bounds	The ellipse bounds.
stroke	Stroke configuration for the ellipse.

Implements donner::svg::RendererInterface.

drawImage()

void donner::svg::Renderer::drawImage ( const ImageResource & image, const ImageParams & params )

overridevirtual

Draws an image resource.

Parameters

image	The image resource to draw.
params	Image placement parameters.

Implements donner::svg::RendererInterface.

drawPath()

void donner::svg::Renderer::drawPath ( const PathShape & path, const StrokeParams & stroke )

overridevirtual

Draws an arbitrary path.

Parameters

path	The path to draw.
stroke	Stroke configuration for the path.

Implements donner::svg::RendererInterface.

drawRect()

void donner::svg::Renderer::drawRect ( const Box2d & rect, const StrokeParams & stroke )

overridevirtual

Draws an axis-aligned rectangle.

Parameters

rect	The rectangle bounds.
stroke	Stroke configuration for the rectangle.

Implements donner::svg::RendererInterface.

drawText()

void donner::svg::Renderer::drawText ( Registry & registry, const components::ComputedTextComponent & text, const TextParams & params )

overridevirtual

Draws shaped text.

Parameters

registry	ECS registry used for resolving paint references.
text	The shaped text runs.
params	Text styling parameters.

Implements donner::svg::RendererInterface.

drawTextureSnapshot()

bool donner::svg::Renderer::drawTextureSnapshot ( const RendererTextureSnapshot & texture, const Box2d & targetRect, double opacity = 1.0, bool pixelated = false )

overridevirtual

Draws a backend-owned texture snapshot when the active backend supports it.

Reimplemented from donner::svg::RendererInterface.

endFrame()

void donner::svg::Renderer::endFrame ( )

overridevirtual

Completes the current render pass.

Implements donner::svg::RendererInterface.

endPatternTile()

void donner::svg::Renderer::endPatternTile ( bool forStroke )

overridevirtual

Ends pattern recording and stores the resulting pattern paint.

Parameters

forStroke

If true, store as stroke paint, otherwise fill paint.

Implements donner::svg::RendererInterface.

height()

int donner::svg::Renderer::height ( ) const

nodiscardoverridevirtual

Returns the rendered height in pixels.

Returns

The rendered height.

Implements donner::svg::RendererInterface.

popClip()

void donner::svg::Renderer::popClip ( )

overridevirtual

Pops the most recent clip.

Implements donner::svg::RendererInterface.

popFilterLayer()

void donner::svg::Renderer::popFilterLayer ( )

overridevirtual

Pops the most recent filter layer.

Implements donner::svg::RendererInterface.

popIsolatedLayer()

void donner::svg::Renderer::popIsolatedLayer ( )

overridevirtual

Pops the most recent isolated layer.

Implements donner::svg::RendererInterface.

popMask()

void donner::svg::Renderer::popMask ( )

overridevirtual

Pops the current mask and composites the masked content.

Implements donner::svg::RendererInterface.

popTransform()

void donner::svg::Renderer::popTransform ( )

overridevirtual

Pops the most recent transform.

Implements donner::svg::RendererInterface.

pushClip()

void donner::svg::Renderer::pushClip ( const ResolvedClip & clip )

overridevirtual

Pushes a clip rect or clip path.

Parameters

clip	The resolved clip to apply.

Implements donner::svg::RendererInterface.

pushFilterLayer()

void donner::svg::Renderer::pushFilterLayer ( const components::FilterGraph & filterGraph, const std::optional< Box2d > & filterRegion )

overridevirtual

Pushes a filter layer.

Parameters

filterGraph	The filter graph to apply when the layer is popped.
filterRegion	Optional filter region bounds in user space.

Implements donner::svg::RendererInterface.

pushIsolatedLayer()

void donner::svg::Renderer::pushIsolatedLayer ( double opacity, MixBlendMode blendMode )

overridevirtual

Pushes an isolated compositing layer.

Parameters

opacity	Group opacity applied when the layer is composited back.
blendMode	Mix-blend-mode applied when the layer is composited back.

Implements donner::svg::RendererInterface.

pushMask()

void donner::svg::Renderer::pushMask ( const std::optional< Box2d > & maskBounds )

overridevirtual

Begins mask rendering.

Parameters

maskBounds

Optional mask bounds clip.

Implements donner::svg::RendererInterface.

pushTransform()

void donner::svg::Renderer::pushTransform ( const Transform2d & transform )

overridevirtual

Pushes a relative transform.

Parameters

transform

The transform to compose with the current matrix.

Implements donner::svg::RendererInterface.

renderElementToBitmap()

RendererBitmap donner::svg::Renderer::renderElementToBitmap ( SVGElement element, Vector2i sizePx )

nodiscard

Rasterize a single SVGElement and its descendant subtree to an RGBA bitmap fitted into a target box.

This renders just the given element + its descendants through an isolated offscreen instance of this renderer, scaled and centered into sizePx with a transparent background. The requested size is a maximum thumbnail extent: the returned bitmap dimensions are computed from the element's nonzero- opacity painted geometry bounds and may be narrower or shorter than sizePx. Layers whose visible bounds cover the root SVG viewBox fit the canvas-visible bounds into the preview cell. The element's own paint and transform are honored. The bounds are clipped to the root SVG viewBox when present so thumbnails show the document-canvas-visible part of a layer; other ancestor clips and opacity are intentionally ignored so the preview shows the element's own artwork rather than how it happens to be clipped in context.

The element's owning document is prepared for rendering under write access for this isolated draw, then its pending render invalidation state is restored so previews do not consume dirty flags needed by another renderer.

Parameters

element	Element whose subtree should be rasterized.
sizePx	Maximum bitmap dimensions in device pixels. Both axes must be positive; otherwise an empty bitmap is returned.

Returns

The rendered RGBA bitmap with a transparent background, or an empty RendererBitmap when the element has no renderable geometry or the inputs are degenerate.

requiresTextureSnapshotPresentation()

bool donner::svg::Renderer::requiresTextureSnapshotPresentation ( ) const

nodiscardoverridevirtual

Returns true when this backend requires direct texture presentation.

Reimplemented from donner::svg::RendererInterface.

save()

bool donner::svg::Renderer::save

(

const char *

filename

)

Saves the last rendered frame to a PNG file.

Parameters

filename

The output PNG filename.

Returns

True if the file was written.

setDebugGeometryOverlay()

void donner::svg::Renderer::setDebugGeometryOverlay ( bool enabled )

overridevirtual

Forwards RendererInterface::setDebugGeometryOverlay to the active backend (no-op for backends without a debug overlay).

Reimplemented from donner::svg::RendererInterface.

setPaint()

void donner::svg::Renderer::setPaint ( const PaintParams & paint )

overridevirtual

Sets the active paint parameters for subsequent draw calls.

Parameters

paint

The resolved paint state.

Implements donner::svg::RendererInterface.

setTransform()

void donner::svg::Renderer::setTransform ( const Transform2d & transform )

overridevirtual

Sets the absolute transform, replacing the current matrix.

Parameters

transform

The transform to apply.

Implements donner::svg::RendererInterface.

takeSnapshot()

RendererBitmap donner::svg::Renderer::takeSnapshot ( ) const

nodiscardoverridevirtual

Captures a CPU-readable snapshot of the current frame.

Returns

A snapshot of the rendered frame.

Implements donner::svg::RendererInterface.

takeTextureSnapshot()

std::shared_ptr< const RendererTextureSnapshot > donner::svg::Renderer::takeTextureSnapshot ( )

nodiscardoverridevirtual

Captures a backend-owned GPU texture snapshot when the active backend supports it.

Reimplemented from donner::svg::RendererInterface.

transitionMaskToContent()

void donner::svg::Renderer::transitionMaskToContent ( )

overridevirtual

Switches from mask rendering to masked content rendering.

Implements donner::svg::RendererInterface.

width()

int donner::svg::Renderer::width ( ) const

nodiscardoverridevirtual

Returns the rendered width in pixels.

Returns

The rendered width.

Implements donner::svg::RendererInterface.

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

• donner/svg/renderer/Renderer.h