FemtoVG Renderer rendering does not match preview

[Promedio]

Bug Description

The default renderer on Windows does not render consistently with the preview in certain cases, such as dorp-shadow of Rectangle, and @linear-gradient with transparent color.

dorp-shadow

Enabling dorp-shadow for Rectangle invariably fails to render the length of drop-shadow-blur correctly, instead it looks like only 5px.

Please see the following code (preview is left):

Rectangle {
	x: root.width * 20%;
	y: root.height * 20%;
	height: 60%;
	width: self.height;
	background: root.background.darker(5%);
	border-radius: 9px;
	drop-shadow-color: darkgray;
	drop-shadow-blur: 2rem;
}

@linear-gradient

This situation is somewhat unique.

Please see the following code (preview is left):

Image {
	source: @image-url("../img/logo.svg");
	height: 110%;
	x: - self.width * 35%;
	y: parent.height * 70% - self.height * 50%;
	rotation-angle: 12deg;
	colorize: @linear-gradient(
		90deg - self.rotation-angle,
		transparent.mix(black, 96%) 35%,
		transparent 120%
	);
}

Where transparent 120% doesn't render any gradient in the default renderer (Slightly right color of logo does not become transparent), but the color mixed by transparent.mix(black, 96%) 35% is normal (Leftmost color of logo).

——These are normal in the Skia renderer.

Environment Details

• Slint Version: 1.9.2
• Platform/OS: Windows 11 22631.4602
• Programming Language: Rust
• Backend/Renderer: Windows default

[Promedio]

Add note about the second problem (@linear-gradient).
It is not the use of transparent that prevents the gradient from being applied, but rather the use of a parameter like 35%; after removing this parameter, the problem disappears.