Apply scales.

Since we don't receive the scaled channels (because we don't want to participate in setting the scales' domains), we have to compute them in reder. We do it once for all the facets, and store the result in the object.

Author: Fil

src/marks/brush.js

@@ -37,6 +37,11 @@ export class Brush extends Mark {
     const g = create("svg:g");
     const data = this.data;
 
+    // compute the scaled channels
+    if (x && this.X === undefined) this.X = X.map(x);
+    if (y && this.Y === undefined) this.Y = Y.map(y);
+    ({X, Y} = this);
+
     const bounds = [
       [Math.floor(marginLeft), Math.floor(marginTop)],
       [Math.ceil(width - marginRight), Math.ceil(height - marginBottom)]
@@ -48,17 +53,11 @@ export class Brush extends Mark {
         if (selection) {
           if (x) {
             const [x0, x1] = y ? [selection[0][0], selection[1][0]] : selection;
-            index = index.filter(i => {
-              const c = x(X[i]);
-              return c >= x0 && c <= x1;
-            });
+            index = index.filter(i => X[i] >= x0 && X[i] <= x1);
           }
           if (y) {
             const [y0, y1] = x ? [selection[0][1], selection[1][1]] : selection;
-            index = index.filter(i => {
-              const c = y(Y[i]);
-              return c >= y0 && c <= y1;
-            });
+            index = index.filter(i => Y[i] >= y0 && Y[i] <= y1);
           }
         }
         const dots = selection ? Array.from(index, i => J[i]) : data;