Add existing to tracked

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

@@ -0,0 +1,27 @@
+// See IntersectionUtils.glsl for the definitions of Ray, Intersections,
+// setIntersectionPair, INF_HIT, NO_HIT
+
+/* intersectDepth defines (set in Scene/VoxelRenderResources.js)
+#define DEPTH_INTERSECTION_INDEX ###
+*/
+
+void intersectDepth(in vec2 screenCoord, in Ray ray, inout Intersections ix) {
+    float logDepthOrDepth = czm_unpackDepth(texture(czm_globeDepthTexture, screenCoord));
+    float entry;
+    float exit;
+    if (logDepthOrDepth != 0.0) {
+        // Calculate how far the ray must travel before it hits the depth buffer.
+        vec4 eyeCoordinateDepth = czm_screenToEyeCoordinates(screenCoord, logDepthOrDepth);
+        eyeCoordinateDepth /= eyeCoordinateDepth.w;
+        entry = dot(eyeCoordinateDepth.xyz - ray.pos, ray.dir);
+        exit = +INF_HIT;
+    } else {
+        // There's no depth at this location.
+        entry = NO_HIT;
+        exit = NO_HIT;
+    }
+    ix.distanceToDepthBuffer = entry;
+#if defined(DEPTH_TEST)
+    setIntersectionPair(ix, DEPTH_INTERSECTION_INDEX, vec2(entry, exit));
+#endif
+}