The copy-and-swap idiom is certainly very cute, but often causes
unnecessary copies. My commit fedafb9352
did exactly that, unfortunately.
Restore the exact same code for the copy-assignment operator as before
commit fedafb935, and add a more efficient implementation for the
move-assignment operator.
As explained by Howard Hinnant in [1] and [2], if some particular piece
of code really needs a strong exception safety guarantee, one can easily
add a specific method for that; this is not a valid reason to make the
code slower for all other places that have no use for such a guarantee!
[1] http://www.slideshare.net/ripplelabs/howard-hinnant-accu2014
[2] https://stackoverflow.com/a/9322542/4756009
In C++11, destructors are 'noexcept' by default -> remove useless
throw() specifiers. There was one case that wasn't about a destructor: I
replaced the 'throw()' with 'noexcept' because this use of 'throw()' is
deprecated and 'noexcept' offers the intended meaning as far as I can
guess (in C++17, 'throw()' will be equivalent to 'noexcept' anyway). For
more info, see:
http://en.cppreference.com/w/cpp/language/noexcept_spechttps://akrzemi1.wordpress.com/2013/08/20/noexcept-destructors/
Avoids codecvt dependency on Unix where it might not be present, eg
with GCC 4.8; on Windows we use <codecvt> since it’s present in VS2015
to avoid writing a seperate UTF-16 <-> UTF-8 conversion.
Designed for 2d objects, such as a canvas placements, this permits the receipt of touch (mouse click) events to enable the simulation of avionics with a touchscreen.
The coordinates are passed in as arguments to the action; these can be accessed with Nasal via the cmdarg() method.
example:
<animation>
<type>touch</type>
<visible>true</visible>
<object-name>VSDImage</object-name>
<action>
<touch>0</touch>
<repeatable>false</repeatable>
<binding>
<command>nasal</command>
<script>print("touch input
(",cmdarg().getNode("x").getValue(),",",cmdarg().getNode("y").getValue())</script>
</binding>
</action>
</animation>
simgear::Dir::isEmpty() used to make up to 5 calls to readdir(), while 3
are enough to say whether the directory has entries other than '.' and
'..'.
Also add an automated test for this method.
This is done so as to avoid confusion with the unrelated classes
ResourceProvider and ResourceManager already present in SimGear.
Despite this new name, EmbeddedResourceProxy is a proxy not only for
embedded resources, but also for real files (hence the initial name
choice): its purpose is precisely to allow zero-work switching from one
data source to the other.
The ResourceProxy class allows one to access real files or embedded
resources in a unified way. When using it, one can switch from one data
source to the other with minimal code changes, possibly even at runtime
(in which case there is obviously no code change at all).
Sample usage (from FlightGear for the globals->get_fg_root() bit):
simgear::ResourceProxy proxy(globals->get_fg_root(), "/FGData");
std::string s = proxy.getString("/some/path");
std::unique_ptr<std::istream> streamp = proxy.getIStream("/some/path");
The methods ResourceProxy::getString(const std::string& path) and
ResourceProxy::getIStream(const std::string& path) decide whether to use
embedded resources or real files depending on the boolean value passed
to ResourceProxy::setUseEmbeddedResources() (also available as an
optional parameter to the ResourceProxy constructor, defaulting to
true). It is often most convenient to set this boolean once and don't
worry about it anymore---it's stored inside the ResourceProxy object.
Otherwise, if you want to fetch resources some times from real files,
other times from embedded resources, you may use the following methods:
// Retrieve contents using embedded resources
std:string s = proxy.getString("/some/path", true);
std:string s = proxy.getStringDecideOnPrefix(":/some/path");
// Retrieve contents using real files
std:string s = proxy.getString("/some/path", false);
std:string s = proxy.getStringDecideOnPrefix("/some/path");
(alternatively, you could use several ResourceProxy objects with
different values for the constructor's third parameter)
By default you can either do
1. axis -> object-name ...
2. axis -> x-m ...
3. omit axis. This will now try to find an 'object-name' with -axis appended. If this can't be found then no message will be output; and the default behaviour of just using (0,0,0) will appyl.
Add a rehash() method to EmbeddedResourceManager::Impl to update
'poolSearchList'. Introduce a 'dirty' flag so that
EmbeddedResourceManager::Impl::rehash() is automatically called whenever
needed. It is not necessary anymore to call
EmbeddedResourceManager::selectLocale() after adding resources: changing
the EmbeddedResourceManager's locale or adding resources are both
operations that set the dirty flag. Whenever someone tries to fetch a
resource for the selected locale and the dirty flag is set, a rehash is
triggered before the actual fetching so as to ensure it is correct.
This should reduce the load on Ibiblio when browsing aircraft, the
package system caches thumbnails for seven days. Also we detect for
certain failure conditions and retry, to deal with Ibiblio’s rate-
limiting mechanism.
MSVC really needs these methods to be out of line, to avoid generating code for the shared pointers
in each translation unit which includes the header.
This fixes the animation bindings to use the defined property tree root - to support multiplayer (or other) model that can bind to the correct part of the property tree.
Requires a corresponding fix in fg to allow the command methods to take an optional root parameter.
What this means is that when inside someone else's multiplayer model (e.g. backseat, or co-pilot), the multipalyer (AI) model will correctly modify properties inside the correct part of the property tree inside (/ai), rather than modifying the properties inside the same part of the tree as the non-ai model.
This means that a properly setup model will operate within it's own space in the property tree; and permit more generic multiplayer code to be written.
This is probably responsible for some of the pollution of the /sim property tree with MP aircraft properties.
