Merge pull request #5363 from penpot/superalex-wasm-shape-opacity

🎉 Shape opacity for wasm render

frontend/src/app/render_wasm/api.cljs

@@ -125,6 +125,10 @@
   ;; https://rust-skia.github.io/doc/skia_safe/enum.BlendMode.html
   (h/call internal-module "_set_shape_blend_mode" (translate-blend-mode blend-mode)))
 
+(defn set-shape-opacity
+  [opacity]
+  (h/call internal-module "_set_shape_opacity" (or opacity 1)))
+
 (def debounce-render-without-cache (fns/debounce render-without-cache 100))
 
 (defn set-view
@@ -146,7 +150,8 @@
               transform  (dm/get-prop shape :transform)
               fills      (dm/get-prop shape :fills)
               children   (dm/get-prop shape :shapes)
-              blend-mode (dm/get-prop shape :blend-mode)]
+              blend-mode (dm/get-prop shape :blend-mode)
+              opacity    (dm/get-prop shape :opacity)]
           (use-shape id)
           (set-shape-selrect selrect)
           (set-shape-rotation rotation)
@@ -154,6 +159,7 @@
           (set-shape-fills fills)
           (set-shape-blend-mode blend-mode)
           (set-shape-children children)
+          (set-shape-opacity opacity)
           (recur (inc index))))))
   (request-render))
 

frontend/src/app/render_wasm/shape.cljs

@@ -100,6 +100,7 @@
       :transform  (api/set-shape-transform v)
       :fills      (api/set-shape-fills v)
       :blend-mode (api/set-shape-blend-mode v)
+      :opacity    (api/set-shape-opacity v)
       :shapes     (api/set-shape-children v)
       nil)
     ;; when something synced with wasm

render-wasm/src/main.rs

@@ -166,6 +166,14 @@ pub extern "C" fn set_shape_blend_mode(mode: i32) {
     }
 }
 
+#[no_mangle]
+pub extern "C" fn set_shape_opacity(opacity: f32) {
+    let state = unsafe { STATE.as_mut() }.expect("got an invalid state pointer");
+    if let Some(shape) = state.current_shape() {
+        shape.opacity = opacity;
+    }
+}
+
 fn main() {
     init_gl();
 }

render-wasm/src/render.rs

@@ -164,6 +164,7 @@ impl RenderState {
 
         let mut paint = skia::Paint::default();
         paint.set_blend_mode(shape.blend_mode.into());
+        paint.set_alpha_f(shape.opacity);
         self.drawing_surface.draw(
             &mut self.final_surface.canvas(),
             (0.0, 0.0),

render-wasm/src/shapes.rs

@@ -104,6 +104,7 @@ pub struct Shape {
     pub rotation: f32,
     fills: Vec<Fill>,
     pub blend_mode: BlendMode,
+    pub opacity: f32,
 }
 
 impl Shape {
@@ -117,6 +118,7 @@ impl Shape {
             rotation: 0.,
             fills: vec![],
             blend_mode: BlendMode::default(),
+            opacity: 1.,
         }
     }