Desktop: Fix bitmap file export not preserving alpha (#3673)

Fix Export not preserving alpha

Author: timon-schelling

desktop/src/render/state.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 use crate::window::Window;
-use crate::wrapper::{Color, TargetTexture, WgpuContext, WgpuExecutor};
+use crate::wrapper::{TargetTexture, WgpuContext, WgpuExecutor};
 
 #[derive(derivative::Derivative)]
 #[derivative(Debug)]
@@ -232,10 +232,7 @@ impl RenderState {
 			return;
 		};
 		let size = glam::UVec2::new(viewport_texture.width(), viewport_texture.height());
-		let result = futures::executor::block_on(
-			self.executor
-				.render_vello_scene_to_target_texture(&scene, size, &Default::default(), Color::TRANSPARENT, &mut self.overlays_texture),
-		);
+		let result = futures::executor::block_on(self.executor.render_vello_scene_to_target_texture(&scene, size, &Default::default(), None, &mut self.overlays_texture));
 		if let Err(e) = result {
 			tracing::error!("Error rendering overlays: {:?}", e);
 			return;

desktop/wrapper/src/lib.rs

@@ -3,8 +3,6 @@ use graphite_editor::application::{Editor, Environment, Host, Platform};
 use graphite_editor::messages::prelude::{FrontendMessage, Message};
 
 pub use graphite_editor::consts::FILE_EXTENSION;
-// TODO: Remove usage of this reexport in desktop create and remove this line
-pub use graphene_std::Color;
 
 pub use wgpu_executor::TargetTexture;
 pub use wgpu_executor::WgpuContext;

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

@@ -112,12 +112,12 @@ unsafe impl StaticType for Surface {
 const VELLO_SURFACE_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8Unorm;
 
 impl WgpuExecutor {
-	pub async fn render_vello_scene_to_texture(&self, scene: &Scene, size: UVec2, context: &RenderContext, background: Color) -> Result<wgpu::Texture> {
+	pub async fn render_vello_scene_to_texture(&self, scene: &Scene, size: UVec2, context: &RenderContext, background: Option<Color>) -> Result<wgpu::Texture> {
 		let mut output = None;
 		self.render_vello_scene_to_target_texture(scene, size, context, background, &mut output).await?;
 		Ok(output.unwrap().texture)
 	}
-	pub async fn render_vello_scene_to_target_texture(&self, scene: &Scene, size: UVec2, context: &RenderContext, background: Color, output: &mut Option<TargetTexture>) -> Result<()> {
+	pub async fn render_vello_scene_to_target_texture(&self, scene: &Scene, size: UVec2, context: &RenderContext, background: Option<Color>, output: &mut Option<TargetTexture>) -> Result<()> {
 		// Initialize (lazily) if this is the first call
 		if output.is_none() {
 			*output = Some(TargetTexture::new(&self.context.device, size));
@@ -126,7 +126,7 @@ impl WgpuExecutor {
 		if let Some(target_texture) = output.as_mut() {
 			target_texture.ensure_size(&self.context.device, size);
 
-			let [r, g, b, a] = background.to_rgba8_srgb();
+			let [r, g, b, a] = background.unwrap_or(Color::TRANSPARENT).to_rgba8_srgb();
 			let render_params = RenderParams {
 				base_color: vello::peniko::Color::from_rgba8(r, g, b, a),
 				width: size.x,

node-graph/nodes/gstd/src/render_node.rs

@@ -189,10 +189,11 @@ async fn render<'a: 'n>(ctx: impl Ctx + ExtractFootprint + ExtractVarArgs, edito
 				}
 			}
 
-			let mut background = Color::from_rgb8_srgb(0x22, 0x22, 0x22);
-			if !contains_artboard && !render_params.hide_artboards {
-				background = Color::WHITE;
-			}
+			let background = if !render_params.for_export && !contains_artboard && !render_params.hide_artboards {
+				Some(Color::WHITE)
+			} else {
+				None
+			};
 
 			let texture = exec
 				.render_vello_scene_to_texture(&scene, physical_resolution, context, background)