Add mix-blend-mode plus-lighter and feComposite operator=lighter

CHANGELOG.md

@@ -8,6 +8,11 @@ This changelog also contains important changes in dependencies.
 
 ## [Unreleased]
 
+### Added
+
+- `mix-blend-mode: plus-lighter` (Compositing and Blending Level 2).
+- `feComposite` `operator="lighter"` (SVG 2).
+
 ### Fixed
 
 - `dominant-baseline` is now correctly inherited by nested `<tspan>` elements,

crates/resvg/src/filter/mod.rs

@@ -785,6 +785,7 @@ fn apply_composite(
         Operator::Out => tiny_skia::BlendMode::SourceOut,
         Operator::Atop => tiny_skia::BlendMode::SourceAtop,
         Operator::Xor => tiny_skia::BlendMode::Xor,
+        Operator::Lighter => tiny_skia::BlendMode::Plus,
         Operator::Arithmetic { .. } => tiny_skia::BlendMode::SourceOver,
     };
 

crates/resvg/src/render.rs

@@ -160,6 +160,7 @@ pub fn convert_blend_mode(mode: usvg::BlendMode) -> tiny_skia::BlendMode {
         usvg::BlendMode::Saturation => tiny_skia::BlendMode::Saturation,
         usvg::BlendMode::Color => tiny_skia::BlendMode::Color,
         usvg::BlendMode::Luminosity => tiny_skia::BlendMode::Luminosity,
+        usvg::BlendMode::PlusLighter => tiny_skia::BlendMode::Plus,
     }
 }
 

crates/resvg/tests/integration/render.rs

@@ -29,6 +29,7 @@ use crate::render;
 #[test] fn filters_enable_background_with_opacity_4() { assert_eq!(render("tests/filters/enable-background/with-opacity-4"), 0); }
 #[test] fn filters_enable_background_with_transform() { assert_eq!(render("tests/filters/enable-background/with-transform"), 0); }
 #[test] fn filters_feBlend_empty() { assert_eq!(render("tests/filters/feBlend/empty"), 0); }
+#[test] fn filters_feBlend_invalid_mode_plus_lighter() { assert_eq!(render("tests/filters/feBlend/invalid-mode-plus-lighter"), 0); }
 #[test] fn filters_feBlend_mode_eq_color_burn() { assert_eq!(render("tests/filters/feBlend/mode=color-burn"), 0); }
 #[test] fn filters_feBlend_mode_eq_darken() { assert_eq!(render("tests/filters/feBlend/mode=darken"), 0); }
 #[test] fn filters_feBlend_mode_eq_hue() { assert_eq!(render("tests/filters/feBlend/mode=hue"), 0); }
@@ -90,6 +91,7 @@ use crate::render;
 #[test] fn filters_feComposite_operator_eq_arithmetic() { assert_eq!(render("tests/filters/feComposite/operator=arithmetic"), 0); }
 #[test] fn filters_feComposite_operator_eq_atop() { assert_eq!(render("tests/filters/feComposite/operator=atop"), 0); }
 #[test] fn filters_feComposite_operator_eq_in() { assert_eq!(render("tests/filters/feComposite/operator=in"), 0); }
+#[test] fn filters_feComposite_operator_eq_lighter() { assert_eq!(render("tests/filters/feComposite/operator=lighter"), 0); }
 #[test] fn filters_feComposite_operator_eq_out() { assert_eq!(render("tests/filters/feComposite/operator=out"), 0); }
 #[test] fn filters_feComposite_operator_eq_over() { assert_eq!(render("tests/filters/feComposite/operator=over"), 0); }
 #[test] fn filters_feComposite_operator_eq_xor() { assert_eq!(render("tests/filters/feComposite/operator=xor"), 0); }
@@ -836,6 +838,7 @@ use crate::render;
 #[test] fn painting_mix_blend_mode_opacity_on_element() { assert_eq!(render("tests/painting/mix-blend-mode/opacity-on-element"), 0); }
 #[test] fn painting_mix_blend_mode_opacity_on_group() { assert_eq!(render("tests/painting/mix-blend-mode/opacity-on-group"), 0); }
 #[test] fn painting_mix_blend_mode_overlay() { assert_eq!(render("tests/painting/mix-blend-mode/overlay"), 0); }
+#[test] fn painting_mix_blend_mode_plus_lighter() { assert_eq!(render("tests/painting/mix-blend-mode/plus-lighter"), 0); }
 #[test] fn painting_mix_blend_mode_saturation() { assert_eq!(render("tests/painting/mix-blend-mode/saturation"), 0); }
 #[test] fn painting_mix_blend_mode_screen() { assert_eq!(render("tests/painting/mix-blend-mode/screen"), 0); }
 #[test] fn painting_mix_blend_mode_soft_light() { assert_eq!(render("tests/painting/mix-blend-mode/soft-light"), 0); }

crates/usvg/src/parser/filter.rs

@@ -626,6 +626,7 @@ fn convert_composite(fe: SvgNode, primitives: &[Primitive]) -> Kind {
         "out" => CompositeOperator::Out,
         "atop" => CompositeOperator::Atop,
         "xor" => CompositeOperator::Xor,
+        "lighter" => CompositeOperator::Lighter,
         "arithmetic" => CompositeOperator::Arithmetic {
             k1: fe.attribute(AId::K1).unwrap_or(0.0),
             k2: fe.attribute(AId::K2).unwrap_or(0.0),

crates/usvg/src/parser/svgtree/mod.rs

@@ -1046,7 +1046,7 @@ impl<'a, 'input: 'a> FromValue<'a, 'input> for ImageRendering {
 }
 
 impl<'a, 'input: 'a> FromValue<'a, 'input> for BlendMode {
-    fn parse(_: SvgNode, _: AId, value: &str) -> Option<Self> {
+    fn parse(_: SvgNode, aid: AId, value: &str) -> Option<Self> {
         match value {
             "normal" => Some(BlendMode::Normal),
             "multiply" => Some(BlendMode::Multiply),
@@ -1064,6 +1064,7 @@ impl<'a, 'input: 'a> FromValue<'a, 'input> for BlendMode {
             "saturation" => Some(BlendMode::Saturation),
             "color" => Some(BlendMode::Color),
             "luminosity" => Some(BlendMode::Luminosity),
+            "plus-lighter" if aid == AId::MixBlendMode => Some(BlendMode::PlusLighter),
             _ => None,
         }
     }

crates/usvg/src/tree/filter.rs

@@ -335,6 +335,7 @@ pub enum CompositeOperator {
     Out,
     Atop,
     Xor,
+    Lighter,
     Arithmetic { k1: f32, k2: f32, k3: f32, k4: f32 },
 }
 

crates/usvg/src/tree/mod.rs

@@ -230,6 +230,7 @@ pub enum BlendMode {
     Saturation,
     Color,
     Luminosity,
+    PlusLighter,
 }
 
 impl Default for BlendMode {
@@ -257,6 +258,7 @@ impl Display for BlendMode {
             BlendMode::Saturation => "saturation",
             BlendMode::Color => "color",
             BlendMode::Luminosity => "luminosity",
+            BlendMode::PlusLighter => "plus-lighter",
         };
         write!(f, "{blend_mode}")
     }

crates/usvg/src/writer.rs

@@ -253,6 +253,7 @@ fn write_filters(tree: &Tree, opt: &WriteOptions, xml: &mut XmlWriter) {
                             filter::CompositeOperator::Out => "out",
                             filter::CompositeOperator::Atop => "atop",
                             filter::CompositeOperator::Xor => "xor",
+                            filter::CompositeOperator::Lighter => "lighter",
                             filter::CompositeOperator::Arithmetic { .. } => "arithmetic",
                         },
                     );

docs/svg2-changelog.md

@@ -193,6 +193,7 @@ Basically everything from [CSS Text Module Level 3](https://www.w3.org/TR/css-te
 - [x] (partial support) A [`paint-order`](https://www.w3.org/TR/SVG2/painting.html#PaintOrder) property.
 - [x] `context-fill` and `context-stroke` variants to the [`<paint>`](https://www.w3.org/TR/SVG2/painting.html#SpecifyingPaint) type.
 - [x] A [`mix-blend-mode`](https://www.w3.org/TR/compositing-1/#mix-blend-mode) property.
+- [x] A `plus-lighter` variant to the [`mix-blend-mode`](https://drafts.csswg.org/compositing-2/#mix-blend-mode) property.
 - [x] An [`isolation`](https://www.w3.org/TR/compositing-1/#isolation) property.
 - [ ] `left`, `center` and `right` variants to `refX` and `refY` properties of the [`marker`](https://www.w3.org/TR/SVG2/painting.html#MarkerElement) element.
 - [x] An `auto-start-reverse` variant to [`orient`](https://www.w3.org/TR/SVG2/painting.html#OrientAttribute) property of the [`marker`](https://www.w3.org/TR/SVG2/painting.html#MarkerElement) element
@@ -252,6 +253,7 @@ Basically everything from [CSS Text Module Level 3](https://www.w3.org/TR/css-te
 - [x] [Filter functions](https://www.w3.org/TR/filter-effects-1/#filter-functions).
 - [x] New [blend modes](https://www.w3.org/TR/compositing-1/#ltblendmodegt) to [`feBlend`](https://www.w3.org/TR/filter-effects-1/#feBlendElement) element.
 - [ ] A [`no-composite`](https://www.w3.org/TR/filter-effects-1/#element-attrdef-feblend-no-composite) property to [`feBlend`](https://www.w3.org/TR/filter-effects-1/#feBlendElement) element.
+- [x] A `lighter` variant to the [`operator`](https://www.w3.org/TR/filter-effects-1/#element-attrdef-fecomposite-operator) attribute of the [`feComposite`](https://www.w3.org/TR/filter-effects-1/#feCompositeElement) element.
 
 ### Changed