Fix blend modes and opacity on raster data (#1996)

* Apply alpha blending to images when using vello

* Fix bounds for image layer

* Fix rendering for non vello images

node-graph/gcore/src/application_io.rs

@@ -1,6 +1,7 @@
 use crate::text::FontCache;
 use crate::transform::{Footprint, Transform, TransformMut};
 use crate::vector::style::ViewMode;
+use crate::AlphaBlending;
 
 use dyn_any::{DynAny, StaticType, StaticTypeSized};
 
@@ -70,6 +71,7 @@ pub struct TextureFrame {
 	#[cfg(not(feature = "wgpu"))]
 	pub texture: (),
 	pub transform: DAffine2,
+	pub alpha_blend: AlphaBlending,
 }
 
 impl Hash for TextureFrame {

node-graph/gcore/src/graphic_element/renderer.rs

@@ -762,6 +762,9 @@ impl GraphicElementRendered for ImageFrame<Color> {
 					if !matrix.is_empty() {
 						attributes.push("transform", matrix);
 					}
+					if self.alpha_blending.opacity < 1. {
+						attributes.push("opacity", self.alpha_blending.opacity.to_string());
+					}
 					if self.alpha_blending.blend_mode != BlendMode::default() {
 						attributes.push("style", self.alpha_blending.blend_mode.render());
 					}
@@ -840,6 +843,9 @@ impl GraphicElementRendered for Raster {
 					if !matrix.is_empty() {
 						attributes.push("transform", matrix);
 					}
+					if blending.opacity < 1. {
+						attributes.push("opacity", blending.opacity.to_string());
+					}
 					if blending.blend_mode != BlendMode::default() {
 						attributes.push("style", blending.blend_mode.render());
 					}
@@ -870,7 +876,7 @@ impl GraphicElementRendered for Raster {
 	fn render_to_vello(&self, scene: &mut Scene, transform: DAffine2, context: &mut RenderContext) {
 		use vello::peniko;
 
-		match self {
+		let (image, blend_mode) = match self {
 			Raster::ImageFrame(image_frame) => {
 				let image = &image_frame.image;
 				if image.data.is_empty() {
@@ -883,9 +889,7 @@ impl GraphicElementRendered for Raster {
 					format: peniko::Format::Rgba8,
 					extend: peniko::Extend::Repeat,
 				};
-				let transform = transform * self.transform() * DAffine2::from_scale(1. / DVec2::new(image.width as f64, image.height as f64));
+				(image, image_frame.alpha_blending)
-
-				scene.draw_image(&image, vello::kurbo::Affine::new(transform.to_cols_array()));
 			}
 			Raster::Texture(texture) => {
 				let image = vello::peniko::Image {
@@ -897,12 +901,23 @@ impl GraphicElementRendered for Raster {
 				};
 				let id = image.data.id();
 				context.ressource_overrides.insert(id, texture.texture.clone());
-
+				(image, texture.alpha_blend)
-				let transform = transform * self.transform() * DAffine2::from_scale(1. / DVec2::new(image.width as f64, image.height as f64));
-
-				scene.draw_image(&image, vello::kurbo::Affine::new(transform.to_cols_array()));
 			}
 		};
+		let image_transform = transform * self.transform() * DAffine2::from_scale(1. / DVec2::new(image.width as f64, image.height as f64));
+		let layer = blend_mode != Default::default();
+
+		let Some(bounds) = self.bounding_box(transform) else { return };
+		let blending = vello::peniko::BlendMode::new(blend_mode.blend_mode.into(), vello::peniko::Compose::SrcOver);
+
+		if layer {
+			let rect = vello::kurbo::Rect::new(bounds[0].x, bounds[0].y, bounds[1].x, bounds[1].y);
+			scene.push_layer(blending, blend_mode.opacity, kurbo::Affine::IDENTITY, &rect);
+		}
+		scene.draw_image(&image, vello::kurbo::Affine::new(image_transform.to_cols_array()));
+		if layer {
+			scene.pop_layer()
+		}
 	}
 }
 

node-graph/wgpu-executor/src/lib.rs

@@ -931,5 +931,6 @@ async fn upload_texture<'a: 'n>(_: (), input: ImageFrame<Color>, executor: &'a W
 	TextureFrame {
 		texture: texture.into(),
 		transform: input.transform,
+		alpha_blend: Default::default(),
 	}
 }