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Donner SVG 0.8.0-pre
SVG editor and embeddable C++20 engine.
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Donner SVG 0.8.0-pre
SVG editor and embeddable C++20 engine.
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Stores a Path used for rendering a shape, which may be generated from the parameters of shapes such as circle, rect, line, poly, and path. More...
#include "donner/svg/components/shape/ComputedPathComponent.h"
Public Member Functions | |
| Box2d | localBounds () const |
| Returns the tight fill bounds of the path in local (pre-transform) space. | |
| Box2d | transformedBounds (const Transform2d &pathFromTarget) |
| Returns the tight bounds of the shape, transformed to the target coordinate system. | |
Public Attributes | |
| Path | spline |
| Path used for rendering the shape. | |
| std::optional< Box2d > | cachedLocalBounds |
| Lazily-populated cache for localBounds(). Left as a public data member (rather than hidden behind a private: section) so the component stays an aggregate - entt's emplace_or_replace<T>(args...) path initializes components via aggregate initialization on older compilers and breaks once a non-public section is added. | |
| std::optional< RcString > | sourcePathData |
| The path-data string that spline was parsed from, when the spline came from path data. | |
Stores a Path used for rendering a shape, which may be generated from the parameters of shapes such as circle, rect, line, poly, and path.
All shapes create computed paths, and these paths can be rendered using a unified rendering pipeline.
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inline |
Returns the tight fill bounds of the path in local (pre-transform) space.
Memoized - Path::bounds() walks every command (O(N) in path size), so hot-path callers (culling, hit-testing, filter-region computation) should prefer this accessor. The cache is tied to the ComputedPathComponent's lifetime; ShapeSystem rebuilds the component whenever the underlying geometry changes, which invalidates the cache. Style-only changes (fill color, opacity, stroke-width) leave the component - and the cached bounds - intact.
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Returns the tight bounds of the shape, transformed to the target coordinate system.
| pathFromTarget | Transform to transform the path to the target coordinate system. |
| std::optional<RcString> donner::svg::components::ComputedPathComponent::sourcePathData |
The path-data string that spline was parsed from, when the spline came from path data.
std::nullopt for every other producer: shapes generated from numeric attributes (circle, ellipse, line, poly, rect), splines supplied directly instead of parsed, and path data whose parse reported a diagnostic.
ShapeSystem uses this to skip re-parsing unchanged path data. Parsing is a pure function of the resolved path-data string, so while the string is unchanged the retained spline is byte-for-byte what a re-parse would produce, and the shape pass can return the retained component untouched. Keeping the key on the computed component rather than beside the source attribute ties its lifetime to the geometry it describes: every writer of this component either sets the key to the string it just parsed or clears it, and every invalidation removes or replaces the component, so a stale key cannot outlive the spline it belongs to.
Cost: sizeof(std::optional<RcString>) is 40 bytes, paid by every ComputedPathComponent, including the numeric-attribute shapes that always leave it empty. Beyond that, path data longer than RcString's inline capacity shares its buffer with the attribute value it was copied from and costs nothing more; shorter path data is held inline, so it is copied.
1.15.0