🎉 Improve frame rendering

frontend/src/app/main/ui/workspace/viewport_wasm.cljs

@@ -285,16 +285,11 @@
 
     (mf/with-effect [base-objects canvas-init?]
       (when @canvas-init?
-        (wasm.api/set-objects base-objects)
-        (wasm.api/draw-objects zoom vbox)))
-
-    (mf/with-effect [modifiers canvas-init?]
-      (when (and @canvas-init? modifiers)
-        (wasm.api/draw-objects zoom vbox)))
+        (wasm.api/set-objects base-objects)))
 
     (mf/with-effect [vbox canvas-init?]
-      (let [frame-id (when @canvas-init? (wasm.api/draw-objects zoom vbox))]
-        (partial wasm.api/cancel-draw frame-id)))
+      (when @canvas-init?
+        (wasm.api/set-view zoom vbox)))
 
     (hooks/setup-dom-events zoom disable-paste in-viewport? read-only? drawing-tool drawing-path?)
     (hooks/setup-viewport-size vport viewport-ref)

frontend/src/app/render_wasm/api.cljs

@@ -13,13 +13,27 @@
    [app.render-wasm.helpers :as h]
    [promesa.core :as p]))
 
+(defonce internal-frame-id nil)
 (defonce internal-module #js {})
 
-(defn create-shape
-  [id]
-  (let [buffer (uuid/get-u32 id)]
-    (h/call internal-module "_create_shape"
-            (aget buffer 0) (aget buffer 1) (aget buffer 2) (aget buffer 3))))
+;; This should never be called from the outside.
+;; This function receives a "time" parameter that we're not using but maybe in the future could be useful (it is the time since
+;; the window started rendering elements so it could be useful to measure time between frames).
+(defn- render
+  [_]
+  (h/call internal-module "_render")
+  (set! internal-frame-id nil))
+
+(defn cancel-render
+  []
+  (when internal-frame-id
+    (js/cancelAnimationFrame internal-frame-id)
+    (set! internal-frame-id nil)))
+
+(defn request-render
+  []
+  (when internal-frame-id (cancel-render))
+  (set! internal-frame-id (js/requestAnimationFrame render)))
 
 (defn use-shape
   [id]
@@ -105,6 +119,11 @@
   ;; 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-view
+  [zoom vbox]
+  (h/call internal-module "_set_view" zoom (- (:x vbox)) (- (:y vbox)))
+  (request-render))
+
 (defn set-objects
   [objects]
   (let [shapes        (into [] (vals objects))
@@ -127,23 +146,11 @@
           (set-shape-fills fills)
           (set-shape-blend-mode blend-mode)
           (set-shape-children children)
-          (recur (inc index)))))))
-
-(defn draw-objects
-  [zoom vbox]
-  (js/requestAnimationFrame
-   (fn []
-     (let [pan-x (- (dm/get-prop vbox :x))
-           pan-y (- (dm/get-prop vbox :y))]
-       (h/call internal-module "_draw_all_shapes" zoom pan-x pan-y)))))
-
-(defn cancel-draw
-  [frame-id]
-  (when (some? frame-id)
-    (js/cancelAnimationFrame frame-id)))
+          (recur (inc index))))))
+  (request-render))
 
 (def ^:private canvas-options
-  #js {:antialias true
+  #js {:antialias false
        :depth true
        :stencil true
        :alpha true})

frontend/src/app/render_wasm/shape.cljs

@@ -101,7 +101,11 @@
       :fills      (api/set-shape-fills v)
       :blend-mode (api/set-shape-blend-mode v)
       :shapes     (api/set-shape-children v)
-      nil))
+      nil)
+    ;; when something synced with wasm
+    ;; is modified, we need to request
+    ;; a new render.
+    (api/request-render))
   (let [delegate  (.-delegate ^ShapeProxy self)
         delegate' (assoc delegate k v)]
     (if (identical? delegate' delegate)

render-wasm/src/main.rs

@@ -2,6 +2,7 @@ pub mod render;
 pub mod shapes;
 pub mod state;
 pub mod utils;
+pub mod view;
 
 use skia_safe as skia;
 
@@ -43,9 +44,9 @@ pub unsafe extern "C" fn resize_surface(width: i32, height: i32) {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn draw_all_shapes(zoom: f32, pan_x: f32, pan_y: f32) {
+pub unsafe extern "C" fn render() {
     let state = unsafe { STATE.as_mut() }.expect("got an invalid state pointer");
-    state.draw_all_shapes(zoom, pan_x, pan_y);
+    state.draw_all_shapes(state.view.zoom, state.view.x, state.view.y);
 }
 
 #[no_mangle]
@@ -54,6 +55,14 @@ pub extern "C" fn reset_canvas() {
     state.render_state().reset_canvas();
 }
 
+#[no_mangle]
+pub extern "C" fn set_view(zoom: f32, x: f32, y: f32) {
+    let state = unsafe { STATE.as_mut() }.expect("got an invalid state pointer");
+    state.view.x = x;
+    state.view.y = y;
+    state.view.zoom = zoom;
+}
+
 #[no_mangle]
 pub extern "C" fn use_shape(a: u32, b: u32, c: u32, d: u32) {
     let state = unsafe { STATE.as_mut() }.expect("got an invalid state pointer");

render-wasm/src/state.rs

@@ -3,6 +3,7 @@ use uuid::Uuid;
 
 use crate::render::RenderState;
 use crate::shapes::Shape;
+use crate::view::View;
 
 /// This struct holds the state of the Rust application between JS calls.
 ///
@@ -14,6 +15,7 @@ pub(crate) struct State<'a> {
     pub current_id: Option<Uuid>,
     pub current_shape: Option<&'a mut Shape>,
     pub shapes: HashMap<Uuid, Shape>,
+    pub view: View,
 }
 
 impl<'a> State<'a> {
@@ -23,6 +25,11 @@ impl<'a> State<'a> {
             current_id: None,
             current_shape: None,
             shapes: HashMap::with_capacity(capacity),
+            view: View {
+                x: 0.,
+                y: 0.,
+                zoom: 1.,
+            }
         }
     }
 

render-wasm/src/view.rs

@@ -0,0 +1,6 @@
+pub(crate) struct View
+{
+  pub x: f32,
+  pub y: f32,
+  pub zoom: f32,
+}