Push touching candidate bounds to integer coords

Author: adroitwhiz

src/RenderWebGL.js

@@ -1284,6 +1284,11 @@ class RenderWebGL extends EventEmitter {
                     drawable.updateMatrix();
                     drawable.skin.updateSilhouette(this._getDrawableScreenSpaceScale(drawable));
                     const candidateBounds = drawable.getFastBounds();
+
+                    // Push bounds out to integers. If a drawable extends out into half a pixel,
+                    // that half-pixel still needs to be tested.
+                    candidateBounds.snapToInt();
+
                     if (bounds.intersects(candidateBounds)) {
                         result.push({
                             id,