private static TControl MatchByUsageAtDeviceRootRecursive <TControl>(InputDevice device, string path, int indexInPath,
ref InputControlList <TControl> matches, bool matchMultiple)
where TControl : InputControl
{
var usages = device.m_UsagesForEachControl;
if (usages == null)
{
return(null);
}
var usageCount = usages.Length;
var startIndex = indexInPath + 1;
var pathCanMatchMultiple = PathComponentCanYieldMultipleMatches(path, indexInPath);
var pathLength = path.Length;
Debug.Assert(path[indexInPath] == '{');
++indexInPath;
if (indexInPath == pathLength)
{
throw new Exception($"Invalid path spec '{path}'; trailing '{{'");
}
TControl lastMatch = null;
for (var i = 0; i < usageCount; ++i)
{
var usage = usages[i];
// Match usage against path.
var usageIsMatch = MatchPathComponent(usage, path, ref indexInPath, PathComponentType.Usage);
// If it isn't a match, go to next usage.
if (!usageIsMatch)
{
indexInPath = startIndex;
continue;
}
var controlMatchedByUsage = device.m_UsageToControl[i];
// If there's more to go in the path, dive into the children of the control.
if (indexInPath < pathLength && path[indexInPath] == '/')
{
lastMatch = MatchChildrenRecursive(controlMatchedByUsage, path, indexInPath + 1,
ref matches, matchMultiple);
// We can stop going through usages if we matched something and the
// path component covering usage does not contain wildcards.
if (lastMatch != null && !pathCanMatchMultiple)
{
break;
}
// We can stop going through usages if we have a match and are only
// looking for a single one.
if (lastMatch != null && !matchMultiple)
{
break;
}
}
else
{
lastMatch = controlMatchedByUsage as TControl;
if (lastMatch != null)
{
if (matchMultiple)
{
matches.Add(lastMatch);
}
else
{
// Only looking for single match and we have one.
break;
}
}
}
}
return(lastMatch);
}
////REVIEW: have mode where instead of matching only the first device that matches a requirement, we match as many
//// as we can get? (could be useful for single-player)
/// <summary>
/// Based on a list of devices, make a selection that matches the <see cref="deviceRequirements">requirements</see>
/// imposed by the control scheme.
/// </summary>
/// <param name="devices">A list of devices to choose from.</param>
/// <returns>A <see cref="MatchResult"/> structure containing the result of the pick. Note that this structure
/// must be manually <see cref="MatchResult.Dispose">disposed</see> or unmanaged memory will be leaked.</returns>
/// <remarks>
/// Does not allocate managed memory.
/// </remarks>
public MatchResult PickDevicesFrom <TDevices>(TDevices devices)
where TDevices : IReadOnlyList <InputDevice>
{
// Empty device requirements match anything while not really picking anything.
if (m_DeviceRequirements == null || m_DeviceRequirements.Length == 0)
{
return(new MatchResult
{
m_Result = MatchResult.Result.AllSatisfied,
});
}
// Go through each requirement and match it.
// NOTE: Even if `devices` is empty, we don't know yet whether we have a NoMatch.
// All our devices may be optional.
var haveAllRequired = true;
var haveAllOptional = true;
var requirementCount = m_DeviceRequirements.Length;
var controls = new InputControlList <InputControl>(Allocator.Persistent, requirementCount);
try
{
var orChainIsSatisfied = false;
var orChainHasRequiredDevices = false;
for (var i = 0; i < requirementCount; ++i)
{
var isOR = m_DeviceRequirements[i].isOR;
var isOptional = m_DeviceRequirements[i].isOptional;
// If this is an OR requirement and we already have a match in this OR chain,
// skip this requirement.
if (isOR && orChainIsSatisfied)
{
// Skill need to add an entry for this requirement.
controls.Add(null);
continue;
}
// Null and empty paths shouldn't make it into the list but make double
// sure here. Simply ignore entries that don't have a path.
var path = m_DeviceRequirements[i].controlPath;
if (string.IsNullOrEmpty(path))
{
controls.Add(null);
continue;
}
// Find the first matching control among the devices we have.
InputControl match = null;
for (var n = 0; n < devices.Count; ++n)
{
var device = devices[n];
// See if we have a match.
var matchedControl = InputControlPath.TryFindControl(device, path);
if (matchedControl == null)
{
continue; // No.
}
// We have a match but if we've already match the same control through another requirement,
// we can't use the match.
if (controls.Contains(matchedControl))
{
continue;
}
match = matchedControl;
break;
}
// Check requirements in AND and OR chains. We look ahead here to find out whether
// the next requirement is starting an OR chain. As the OR combines with the previous
// requirement in the list, this affects our current requirement.
var nextIsOR = i + 1 < requirementCount && m_DeviceRequirements[i + 1].isOR;
if (nextIsOR)
{
// Shouldn't get here if the chain is already satisfied. Should be handled
// at beginning of loop and we shouldn't even be looking at finding controls
// in that case.
Debug.Assert(!orChainIsSatisfied);
// It's an OR with the next requirement. Depends on the outcome of other matches whether
// we're good or not.
if (match != null)
{
// First match in this chain.
orChainIsSatisfied = true;
}
else
{
// Chain not satisfied yet.
if (!isOptional)
{
orChainHasRequiredDevices = true;
}
}
}
else if (isOR && i == requirementCount - 1)
{
// It's an OR at the very end of the requirements list. Terminate
// the OR chain.
if (match == null)
{
if (orChainHasRequiredDevices)
{
haveAllRequired = false;
}
else
{
haveAllOptional = false;
}
}
}
else
{
// It's an AND.
if (match == null)
{
if (isOptional)
{
haveAllOptional = false;
}
else
{
haveAllRequired = false;
}
}
// Terminate ongoing OR chain.
if (i > 0 && m_DeviceRequirements[i - 1].isOR)
{
if (!orChainIsSatisfied)
{
if (orChainHasRequiredDevices)
{
haveAllRequired = false;
}
else
{
haveAllOptional = false;
}
}
orChainIsSatisfied = false;
}
}
// Add match to list. Maybe null.
controls.Add(match);
}
// We should have matched each of our requirements.
Debug.Assert(controls.Count == requirementCount);
}
catch (Exception)
{
controls.Dispose();
throw;
}
return(new MatchResult
{
m_Result = !haveAllRequired
? MatchResult.Result.MissingRequired
: !haveAllOptional
? MatchResult.Result.MissingOptional
: MatchResult.Result.AllSatisfied,
m_Controls = controls,
m_Requirements = m_DeviceRequirements,
});
}
////TODO: refactor this to use the new PathParser
/// <summary>
/// Recursively match path elements in <paramref name="path"/>.
/// </summary>
/// <param name="control">Current control we're at.</param>
/// <param name="path">Control path we are matching against.</param>
/// <param name="indexInPath">Index of current component in <paramref name="path"/>.</param>
/// <param name="matches"></param>
/// <param name="matchMultiple"></param>
/// <typeparam name="TControl"></typeparam>
/// <returns></returns>
private static TControl MatchControlsRecursive <TControl>(InputControl control, string path, int indexInPath,
ref InputControlList <TControl> matches, bool matchMultiple)
where TControl : InputControl
{
var pathLength = path.Length;
// Try to get a match. A path spec has three components:
// "<layout>{usage}name"
// All are optional but at least one component must be present.
// Names can be aliases, too.
// We don't tap InputControl.path strings of controls so as to not create a
// bunch of string objects while feeling our way down the hierarchy.
var controlIsMatch = true;
// Match by layout.
if (path[indexInPath] == '<')
{
++indexInPath;
controlIsMatch =
MatchPathComponent(control.layout, path, ref indexInPath, PathComponentType.Layout);
// If the layout isn't a match, walk up the base layout
// chain and match each base layout.
if (!controlIsMatch)
{
var baseLayout = control.m_Layout;
while (InputControlLayout.s_Layouts.baseLayoutTable.TryGetValue(baseLayout, out baseLayout))
{
controlIsMatch = MatchPathComponent(baseLayout, path, ref indexInPath,
PathComponentType.Layout);
if (controlIsMatch)
{
break;
}
}
}
}
// Match by usage.
if (indexInPath < pathLength && path[indexInPath] == '{' && controlIsMatch)
{
++indexInPath;
for (var i = 0; i < control.usages.Count; ++i)
{
controlIsMatch = MatchPathComponent(control.usages[i], path, ref indexInPath, PathComponentType.Usage);
if (controlIsMatch)
{
break;
}
}
}
// Match by name.
if (indexInPath < pathLength && controlIsMatch && path[indexInPath] != '/')
{
// Normal name match.
controlIsMatch = MatchPathComponent(control.name, path, ref indexInPath, PathComponentType.Name);
// Alternative match by alias.
if (!controlIsMatch)
{
for (var i = 0; i < control.aliases.Count && !controlIsMatch; ++i)
{
controlIsMatch = MatchPathComponent(control.aliases[i], path, ref indexInPath,
PathComponentType.Name);
}
}
}
// If we have a match, return it or, if there's children, recurse into them.
if (controlIsMatch)
{
// If we ended up on a wildcard, we've successfully matched it.
if (indexInPath < pathLength && path[indexInPath] == '*')
{
++indexInPath;
}
// If we've reached the end of the path, we have a match.
if (indexInPath == pathLength)
{
// Check type.
if (!(control is TControl match))
{
return(null);
}
if (matchMultiple)
{
matches.Add(match);
}
return(match);
}
// If we've reached a separator, dive into our children.
if (path[indexInPath] == '/')
{
++indexInPath;
// Silently accept trailing slashes.
if (indexInPath == pathLength)
{
// Check type.
if (!(control is TControl match))
{
return(null);
}
if (matchMultiple)
{
matches.Add(match);
}
return(match);
}
// See if we want to match children by usage or by name.
TControl lastMatch;
if (path[indexInPath] == '{')
{
////TODO: support scavenging a subhierarchy for usages
if (!ReferenceEquals(control.device, control))
{
throw new NotImplementedException(
"Matching usages inside subcontrols instead of at device root");
}
// Usages are kind of like entry points that can route to anywhere else
// on a device's control hierarchy and then we keep going from that re-routed
// point.
lastMatch = MatchByUsageAtDeviceRootRecursive(control.device, path, indexInPath, ref matches, matchMultiple);
}
else
{
// Go through children and see what we can match.
lastMatch = MatchChildrenRecursive(control, path, indexInPath, ref matches, matchMultiple);
}
return(lastMatch);
}
}
return(null);
}
