Add focal point, focal radius

[jsjgdh]

Enhance gradient functionality with new features:

• Focal point & radius for radial gradients — allows off-center starts and elliptical falloffs, matching the SVG fx/fy/fr attributes
• SVG import/export fidelity — radial gradients now correctly round-trip with focal data, named CSS colors and short hex codes are parsed on import, percentage-based stop offsets are supported, and href-based stop inheritance is handled
• Rendering improvements — updated peniko radial positioning.

[jsjgdh]

@cubic-dev

[cubic-dev-ai]

@cubic-dev

@jsjgdh I have started the AI code review. It will take a few minutes to complete.

[gemini-code-assist]

Code Review

This pull request enhances gradient support by introducing focal points, focal radii, and gradient units to the Gradient structure. It improves SVG import capabilities by adding support for percentage-based offsets, 3-digit hex colors, and named CSS colors via the svgtypes crate. Additionally, it implements a mechanism for gradient stops to inherit from other gradients using href. Feedback focuses on making the href resolution more robust to handle multi-level or out-of-order references and simplifying the color parsing logic to better utilize the svgtypes library and correctly handle alpha multiplication.

[cubic-dev-ai]

1 issue found across 10 files

Confidence score: 4/5

• This PR looks generally safe to merge, but there is a moderate, user-visible rendering issue in editor/src/messages/portfolio/document/graph_operation/graph_operation_message_handler.rs where parsed color alpha is dropped.
• The most significant impact is that stop-colors using embedded alpha (for example rgba(...), hsla(...), or 8-digit hex) may render with incorrect opacity, which can change gradient appearance.
• Given the single mid-severity finding (5/10) with good confidence, this is a limited-risk fix area rather than a likely broad regression.
• Pay close attention to editor/src/messages/portfolio/document/graph_operation/graph_operation_message_handler.rs - preserve and propagate c.alpha when converting parsed colors.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="editor/src/messages/portfolio/document/graph_operation/graph_operation_message_handler.rs">

<violation number="1" location="editor/src/messages/portfolio/document/graph_operation/graph_operation_message_handler.rs:625">
P2: `svgtypes::Color::from_str` already parses alpha for formats like `rgba(...)`, `hsla(...)`, and 8-digit hex, but the alpha component (`c.alpha`) is discarded here. This means any stop-color with an embedded alpha channel will lose it. Furthermore, per SVG2, the final opacity should be `(c.alpha / 255) * stop_opacity` — a product of the color's alpha and the `stop-opacity` attribute — but `parse_stop_color` currently uses `alpha.unwrap_or(opacity)`, choosing one or the other instead of multiplying them.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[jsjgdh]

@cubic-dev

[cubic-dev-ai]

@cubic-dev

@jsjgdh I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

1 issue found across 11 files

Confidence score: 3/5

• In node-graph/libraries/rendering/src/render_ext.rs, the gradientUnits write condition appears inverted, so UserSpaceOnUse is skipped and SVG renderers can fall back to the default coordinate space, producing visibly incorrect gradients for affected exports — fix the condition (and ideally add a regression test for UserSpaceOnUse) before merging.

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="node-graph/libraries/rendering/src/render_ext.rs">

<violation number="1" location="node-graph/libraries/rendering/src/render_ext.rs:57">
P1: `gradientUnits` emission condition is inverted: `UserSpaceOnUse` (non-default) is omitted, causing SVG consumers to misinterpret the gradient coordinate space</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P1: gradientUnits emission condition is inverted: UserSpaceOnUse (non-default) is omitted, causing SVG consumers to misinterpret the gradient coordinate space

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At node-graph/libraries/rendering/src/render_ext.rs, line 57:

<comment>`gradientUnits` emission condition is inverted: `UserSpaceOnUse` (non-default) is omitted, causing SVG consumers to misinterpret the gradient coordinate space</comment>

<file context>
@@ -54,21 +54,39 @@ impl RenderExt for Gradient {
 			format!(r#" spreadMethod="{}""#, self.spread_method.svg_name())
 		};
 
+		let gradient_units = if self.gradient_units == GradientUnits::UserSpaceOnUse {
+			String::new()
+		} else {
</file context>