Switch to sRGBA everywhere

showbits-common/src/view.rs

@@ -1,15 +1,15 @@
-use image::RgbImage;
-use palette::Srgb;
+use image::RgbaImage;
+use palette::{blend::Compose, Srgba};
 
 use crate::{color, Rect, Vec2};
 
 pub struct View<'a> {
     area: Rect,
-    buffer: &'a mut RgbImage,
+    buffer: &'a mut RgbaImage,
 }
 
 impl<'a> View<'a> {
-    pub fn new(buffer: &'a mut RgbImage) -> Self {
+    pub fn new(buffer: &'a mut RgbaImage) -> Self {
         let size = Vec2::from_u32(buffer.width(), buffer.height());
         let area = Rect::from_nw(Vec2::ZERO, size);
         Self { area, buffer }
@@ -35,22 +35,30 @@ impl<'a> View<'a> {
         pos + self.area.corner_nw()
     }
 
-    pub fn get(&self, pos: Vec2) -> Option<Srgb> {
+    pub fn get(&self, pos: Vec2) -> Option<Srgba> {
         let (x, y) = self.pos_to_buffer_pos(pos).to_u32();
         let pixel = self.buffer.get_pixel_checked(x, y)?;
-        Some(color::from_image_rgb(*pixel))
+        Some(color::from_image_color(*pixel))
     }
 
-    pub fn set(&mut self, pos: Vec2, color: Srgb) {
+    pub fn set(&mut self, pos: Vec2, color: Srgba) {
         let (x, y) = self.pos_to_buffer_pos(pos).to_u32();
         if let Some(pixel) = self.buffer.get_pixel_mut_checked(x, y) {
-            *pixel = color::to_image_rgb(color);
+            let below = color::from_image_color(*pixel);
+            *pixel = color::to_image_color(color.atop(below));
+        }
+    }
+
+    pub fn replace(&mut self, pos: Vec2, color: Srgba) {
+        let (x, y) = self.pos_to_buffer_pos(pos).to_u32();
+        if let Some(pixel) = self.buffer.get_pixel_mut_checked(x, y) {
+            *pixel = color::to_image_color(color);
         }
     }
 
     // More complicated drawing primitives
 
-    pub fn rect(&mut self, area: Rect, color: Srgb) {
+    pub fn rect(&mut self, area: Rect, color: Srgba) {
         let nw = area.corner_nw();
         let se = area.corner_se();
         for y in nw.y..=se.y {