Add existing to tracked

node_modules/@cesium/engine/Source/Shaders/Voxels/IntersectBox.glsl

@@ -0,0 +1,34 @@
+// See IntersectionUtils.glsl for the definitions of Ray, RayShapeIntersection,
+// NO_HIT, Intersections
+
+/* Box defines (set in Scene/VoxelBoxShape.js)
+#define BOX_INTERSECTION_INDEX ### // always 0
+*/
+
+uniform sampler2D u_renderBoundPlanesTexture;
+
+RayShapeIntersection intersectBoundPlanes(in Ray ray) {
+    vec4 lastEntry = vec4(ray.dir, -INF_HIT);
+    vec4 firstExit = vec4(-ray.dir, +INF_HIT);
+    for (int i = 0; i < 6; i++) {
+        vec4 boundPlane = getBoundPlane(u_renderBoundPlanesTexture, i);
+        vec4 intersection = intersectPlane(ray, boundPlane);
+        if (dot(ray.dir, boundPlane.xyz) < 0.0) {
+            lastEntry = intersection.w > lastEntry.w ? intersection : lastEntry;
+        } else {
+            firstExit = intersection.w < firstExit.w ? intersection: firstExit;
+        }
+    }
+
+    if (lastEntry.w < firstExit.w) {
+        return RayShapeIntersection(lastEntry, firstExit);
+    } else {
+        return RayShapeIntersection(vec4(-ray.dir, NO_HIT), vec4(ray.dir, NO_HIT));
+    }
+}
+
+void intersectShape(in Ray rayUV, in  Ray rayEC, inout Intersections ix)
+{
+    RayShapeIntersection intersection = intersectBoundPlanes(rayEC);
+    setShapeIntersection(ix, BOX_INTERSECTION_INDEX, intersection);
+}