WIP a

frontend/src/app/render_wasm/api.cljs

@@ -1575,10 +1575,17 @@
 
 (def ^:private default-context-options
   #js {:antialias false
-       :depth true
+       ;; Depth is not needed for 2D canvas rendering and can add driver work.
+       :depth false
        :stencil true
        :alpha true
-       "preserveDrawingBuffer" true})
+       ;; Preserving the drawing buffer forces extra GPU/driver work and can
+       ;; stall every frame; we re-render explicitly so it is unnecessary for
+       ;; the viewport and hurts FPS during interactions like drag.
+       "preserveDrawingBuffer" false
+       ;; Hint the browser/ANGLE to reduce compositor-induced stalls.
+       "desynchronized" true
+       "powerPreference" "high-performance"})
 
 (defn resize-viewbox
   [width height]

render-wasm/src/render.rs

@@ -1768,6 +1768,7 @@ impl RenderState {
 
         performance::end_measure!("start_render_loop");
         performance::end_timed_log!("start_render_loop", _start);
+
         Ok(())
     }
 
@@ -1826,7 +1827,12 @@ impl RenderState {
             // still need to flush every rAF so the user sees the updated
             // shape position — render_from_cache is not in the loop here.
             if !self.options.is_viewport_interaction() {
-                self.flush_and_submit();
+                // self.gpu_state.context.flush_and_submit();
+                if self.options.is_interactive_transform() {
+                    self.gpu_state.context.flush_and_submit();
+                } else {
+                    self.flush_and_submit();
+                }                
             } else {
                 self.gpu_state.context.flush_and_submit();
             }