Make more use of temporary string objects in the TimeQuantizer

Add GPU markers to the rendering

include/openspace/util/spicemanager.h

@@ -33,11 +33,15 @@
 #include <string>
 #include <vector>
 #include <set>
+#include "SpiceUsr.h"
+#include "SpiceZpr.h"
 
 namespace openspace {
 
 namespace scripting { struct LuaLibrary; }
 
+void throwSpiceError(const std::string& errorMessage);
+
 class SpiceManager {
 public:
     BooleanType(UseException);
@@ -462,6 +466,7 @@ public:
      * \sa http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/str2et_c.html
      */
     double ephemerisTimeFromDate(const std::string& timeString) const;
+    double ephemerisTimeFromDate(const char* timeString) const;
 
     /**
      * Converts the passed \p ephemerisTime into a human-readable date string with a
@@ -476,11 +481,33 @@ public:
      *
      * \sa http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/timout_c.html
      */
+    template <int N = 31>
     std::string dateFromEphemerisTime(double ephemerisTime,
-        std::string_view format = "YYYY MON DDTHR:MN:SC.### ::RND") const;
+        const char (&format)[N] = "YYYY MON DDTHR:MN:SC.### ::RND") const
+    {
+        static_assert(N != 0, "Format must not be empty");
 
+        std::string res;
+        res.resize(N);
+        dateFromEphemerisTime(ephemerisTime, res.data(), N, format);
+        return res;
+    }
+
+    template <int N>
     void dateFromEphemerisTime(double ephemerisTime, char* outBuf, int bufferSize,
-        std::string_view format = "YYYY MON DDTHR:MN:SC.### ::RND") const;
+        const char (&format)[N] = "YYYY MON DDTHR:MN:SC.### ::RND") const
+    {
+        static_assert(N != 0, "Format must not be empty");
+        ghoul_assert(N > bufferSize - 1, "Buffer size too small");
+
+        timout_c(ephemerisTime, format, bufferSize - 1, outBuf);
+        if (failed_c()) {
+            throwSpiceError(fmt::format(
+                "Error converting ephemeris time '{}' to date with format '{}'",
+                    ephemerisTime, format
+            ));
+        }
+    }
 
     /**
      * Returns the \p position of a \p target body relative to an \p observer in a

include/openspace/util/time.h

@@ -64,6 +64,7 @@ public:
      * \pre \p timeString must not be empty
      */
     static double convertTime(const std::string& time);
+    static double convertTime(const char* time);
 
     explicit Time(double secondsJ2000 = -1);
     explicit Time(const std::string& time);
@@ -113,13 +114,13 @@ public:
      * thus also compliant with the Spice library.
      * \return The current time as a formatted date string
      */
-    std::string UTC() const;
+    std::string_view UTC() const;
 
     /**
     * Returns the current time as a ISO 8601 formatted, i.e YYYY-MM-DDThh:mm:ssZ
     * \return The current time as a ISO 8601 formatted string
     */
-    std::string ISO8601() const;
+    std::string_view ISO8601() const;
 
     /**
      * Advances the simulation time using the deltaTime() and the <code>tickTime</code>.