Text does not have transparency in tiny_skia renderer

[Koranir]

Is there an existing issue for this?

• I have searched the existing issues.

Is this issue related to iced?

• My hardware is compatible and my graphics drivers are up-to-date.

What happened?

When rendering text using the tiny_skia renderer, the alpha channel is not respected.

When the text is rasterized and cached, it ignores the alpha component (which is quite reasonable, as it makes it so that if the alpha component changes slightly it does not have to be re-rasterized), but the alpha component is not added back later.
This is because the default blending:

iced/tiny_skia/src/text.rs

Line 249 in c635290

&tiny_skia::PixmapPaint::default(),

Has a full 100% transparency.
The fix is simple enough, as the color is already available at:

iced/tiny_skia/src/text.rs

Line 199 in c635290

color: Color,

Which could then be substituted into the blending with a:

&PixmapPaint {
    opacity: color.a,
    ..Default::default()
}

(the blend mode might have to be changed as well)

Note: I haven't checked whether the individual glyph's option color (glyph.color_opt from run.glyphs) has an alpha value and should multiply with the original alpha.

What is the expected behavior?

The text should be rendered with transparency.

Version

master

Operating System

Linux

Do you have any log output?

No response