Variations in Theme::from_source_color

[allan2]

Issue

#5 related

I was looking into the variations in theme outputs and this is what I've learned:

1. This crates's Theme::from_source_color is similar to Material Theme Builder's, but not identical. Mismatched colors comparing to Material Theme Builder #5 (comment)
2. The JS themeFromSourceColor is based on CorePalette.of(source).
3. This crate's CorePalette is correct, matching C++ and JS implementations.
4. The JS themeFromSourceColor is not the same as Material Theme Builder or this crate's.

Proposed

1. Document the behaviour above theme_from_source_color.
2. Offer a version of theme_from_source_color that behaves like the JS implementation (where primary is CorePalette::of(source).primary.tone(40).

In my testing, I have already written a lot of the code to do the second version. It would be a scheme based on MaterialLightColorSchemeFromPalette:

impl SchemeFromPalette {
    /// Generates a light colour scheme from a core palette.
    ///
    /// This has less fields than [`Scheme`].
    pub fn light(argb: Argb) -> Self {
        let palette = CorePalette::of(argb);

        Self {
            primary: palette.primary.tone(40),
            on_primary: palette.primary.tone(100),
            primary_container: palette.primary.tone(90),
            on_primary_container: palette.primary.tone(10),
            secondary: palette.secondary.tone(40),
            on_secondary: palette.secondary.tone(100),
            secondary_container: palette.secondary.tone(90),
            on_secondary_container: palette.secondary.tone(10),
            tertiary: palette.tertiary.tone(40),
            on_tertiary: palette.tertiary.tone(100),
            tertiary_container: palette.tertiary.tone(90),
            on_tertiary_container: palette.tertiary.tone(10),
            error: palette.error.tone(40),
            on_error: palette.error.tone(100),
            error_container: palette.error.tone(90),
            on_error_container: palette.error.tone(10),
            background: palette.neutral.tone(99),
            on_background: palette.neutral.tone(10),
            surface: palette.neutral.tone(99),
            on_surface: palette.neutral.tone(10),
            surface_variant: palette.neutral_variant.tone(90),
            on_surface_variant: palette.neutral_variant.tone(30),
            outline: palette.neutral_variant.tone(50),
            outline_variant: palette.neutral_variant.tone(80),
            shadow: palette.neutral.tone(0),
            scrim: palette.neutral.tone(0),
            inverse_surface: palette.neutral.tone(20),
            inverse_on_surface: palette.neutral.tone(95),
            inverse_primary: palette.primary.tone(80),
        }
    }

[Aiving]

closed in 0.3.0