Make laser longer, only show cursor on intersection

The combination of a 1m length laser and showing a cursor
at 1m distance is visually very confusing when trying to
hit objects, especially when doing quick tests on a
mirror display without wearing the headset.

Instead, use a long laser beam, and only show a cursor
when there's a valid intersection with the scene.

Change-Id: Id4178b1ba72994c9148d53c8bc58f041fb42520d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1506463Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: Klaus Weidner <klausw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638266}

third_party/webxr_test_pages/webxr-samples/js/cottontail/src/nodes/input-renderer.js

@@ -43,7 +43,7 @@ const LASER_TEXTURE_DATA = new Uint8Array([
 0xcc, 0xcc, 0xcc, 0x05, 0xbf, 0xbf, 0xbf, 0x04, 0xff, 0xff, 0xff, 0x02, 0xff, 0xff, 0xff, 0x01,
 ]);
 
-const LASER_LENGTH = 1.0;
+const LASER_LENGTH = 10.0;
 const LASER_DIAMETER = 0.01;
 const LASER_FADE_END = 0.535;
 const LASER_FADE_POINT = 0.5335;

third_party/webxr_test_pages/webxr-samples/js/cottontail/src/scenes/scene.js

@@ -128,23 +128,6 @@ export class Scene extends Node {
           }
           hitResult.node._hoverFrameId = this._hoverFrame;
           newHoveredNodes.push(hitResult.node);
-        } else {
-          // Statically render the cursor 1 meters down the ray since we didn't
-          // hit anything selectable.
-          let cursorDistance = 1.0;
-          let cursorPos = vec3.fromValues(
-              inputPose.targetRay.origin.x,
-              inputPose.targetRay.origin.y,
-              inputPose.targetRay.origin.z
-              );
-          vec3.add(cursorPos, cursorPos, [
-              inputPose.targetRay.direction.x * cursorDistance,
-              inputPose.targetRay.direction.y * cursorDistance,
-              inputPose.targetRay.direction.z * cursorDistance,
-              ]);
-          // let cursorPos = vec3.fromValues(0, 0, -1.0);
-          // vec3.transformMat4(cursorPos, cursorPos, inputPose.targetRay);
-          this.inputRenderer.addCursor(cursorPos);
         }
       }
     }