Fix transform logic for mask node (#1134)

Fix transform logic for mask node + other fixes

* Fixes the transform logic for the mask node reverting the breakage
introduced by the color pr

* Actually modifies the pixel values

* Fix storage format for images

* Export images as unassociated alpha

node-graph/gcore/src/raster.rs

@@ -105,6 +105,10 @@ pub trait Pixel: Clone + Pod + Zeroable {
 	fn from_bytes(bytes: &[u8]) -> &Self {
 		bytemuck::try_from_bytes(bytes).expect("Failed to convert bytes to pixel")
 	}
+
+	fn byte_size() -> usize {
+		std::mem::size_of::<Self>()
+	}
 }
 impl<T: Serde + Clone + Pod + Zeroable> Pixel for T {}
 
@@ -138,7 +142,7 @@ pub trait Alpha {
 	fn a(&self) -> Self::AlphaChannel {
 		self.alpha()
 	}
-	fn multiply_alpha(&self, alpha: Self::AlphaChannel) -> Self;
+	fn multiplied_alpha(&self, alpha: Self::AlphaChannel) -> Self;
 }
 
 pub trait Depth {
@@ -565,7 +569,7 @@ mod image {
 
 			let color_from_chunk = |chunk: &[u8]| P::from_bytes(chunk.try_into().unwrap()).clone();
 
-			let colors_from_bytes = |bytes: Vec<u8>| bytes.chunks_exact(4).map(color_from_chunk).collect();
+			let colors_from_bytes = |bytes: Vec<u8>| bytes.chunks_exact(P::byte_size()).map(color_from_chunk).collect();
 
 			String::deserialize(deserializer)
 				.and_then(|string| base64::decode(string).map_err(|err| Error::custom(err.to_string())))
@@ -656,7 +660,7 @@ mod image {
 	}
 
 	use super::*;
-	impl<P: Alpha + RGB> Image<P>
+	impl<P: Alpha + RGB + AssociatedAlpha> Image<P>
 	where
 		P::ColorChannel: Linear,
 	{
@@ -671,9 +675,9 @@ mod image {
 				.into_iter()
 				.flat_map(|color| {
 					[
-						to_u8(to_gamma(color.r())),
-						to_u8(to_gamma(color.g())),
-						to_u8(to_gamma(color.b())),
+						to_u8(to_gamma(color.r() / color.a().to_channel())),
+						to_u8(to_gamma(color.g() / color.a().to_channel())),
+						to_u8(to_gamma(color.b() / color.a().to_channel())),
 						(num::cast::<_, f32>(color.a()).unwrap() * 255.) as u8,
 					]
 				})

node-graph/gcore/src/raster/color.rs

@@ -57,7 +57,7 @@ impl Alpha for Color {
 	fn alpha(&self) -> f32 {
 		self.alpha
 	}
-	fn multiply_alpha(&self, alpha: Self::AlphaChannel) -> Self {
+	fn multiplied_alpha(&self, alpha: Self::AlphaChannel) -> Self {
 		Self {
 			red: self.red * alpha,
 			green: self.green * alpha,

node-graph/gstd/src/raster.rs

@@ -239,17 +239,18 @@ fn mask_image<
 	}
 
 	// Transforms a point from the background image to the forground image
-	let bg_to_fg = DAffine2::from_scale(mask_size) * stencil.transform().inverse() * image.transform() * DAffine2::from_scale(1. / image_size);
+	let bg_to_fg = image.transform() * DAffine2::from_scale(1. / image_size);
 
 	for y in 0..image.height() {
 		for x in 0..image.width() {
 			let image_point = DVec2::new(x as f64, y as f64);
 			let mut mask_point = bg_to_fg.transform_point2(image_point);
-			mask_point = mask_point.clamp(DVec2::ZERO, mask_size);
+			let local_mask_point = stencil.transform().inverse().transform_point2(mask_point);
+			mask_point = stencil.transform().transform_point2(local_mask_point.clamp(DVec2::ZERO, DVec2::ONE));
 
 			let image_pixel = image.get_pixel_mut(x as u32, y as u32).unwrap();
 			if let Some(mask_pixel) = stencil.sample(mask_point) {
-				image_pixel.multiply_alpha(mask_pixel.l().to_channel());
+				*image_pixel = image_pixel.multiplied_alpha(mask_pixel.l().to_channel());
 			}
 		}
 	}