Add LEDReader and LEDWriter helper interfaces to facilitate composing simple patterns into more complex ones, e.g. LEDPattern.solid(Color.kBlue).breathe(Seconds.of(0.75)). Pattern composition relies on changing out the write behavior; for example, offsetBy increments the indexes to write to; while blink will switch between playing a base pattern and turning off all the LEDs.
Add a view class for splitting a single large buffer into smaller distinct sections, which is useful for dealing with long chained LED strips mounted on different parts of a robot. Views cannot be written directly to an LED strip (in fact, trying to do so won't even compile).
Adds some utility methods to the Color class for interpolating between two colors, and support color representations with 32-bit integers to avoid object allocations.
Co-authored-by: Tyler Veness <calcmogul@gmail.com>
This is a cleanup of the FlywheelSim class with a few added features.
- One FlywheelSim constructor that takes a plant, DCMotor, and a optional number of measurementStdDevs. The documentation now states how to construct the plant either through LinearSystemId.createFlywheelSystem or identifyVelocitySystem.
- The gearbox, gearing and moment of Inertia (J) are now private final fields. The gearing is determined from the plant in the constructor as well as the moment of inertia. There are getter methods that allow the flywheelSim to return the gearbox, gearing, and moment of inertia.
- The getCurrentDrawAmps function now uses m_x instead of getAngularVelocityRadPerSec in accordance with more accuracy and matches the patter in other sims.
- Added getter methods for the InputVoltage, angularAcceleration and torque
- (Java only) A third getter method for returning the AngularVelocity of the flywheel using a MutableMeasure as a backing field that is set when getAngularVelocity is called. This summarily returns the angularVelocity as just a Measure object. This allows the user of this class to handle unit conversions with less numerical manipulation. Alterations in C++ for this feature were not needed.
Modified Java constructors to take a variable number of measurement std devs argument with checks in place to make sure the right amount (or none) are passed into the constructor. All changes passed down to classes utilizing LinearSystemSim.
Removed excess constructors
Removed Java and C++ CurrentDrawAmps method as it doesn't belong in a generic (non electrical) linear system. Kept a non override version in all derived electrical classes.
Also LinearSystemSim has now been made agnostic to electrical systems. Inputs don't have to be voltage. BatteryVoltage clamp function has been pushed down to electrical subclasses.
Co-authored-by: Tyler Veness <calcmogul@gmail.com>
Currently in the entire C API of WPILib we have ~8 different ways of handling strings. The C API actually isn't built for pure C callers (We don't actually have any of those). Instead, they're built for interop between languages like LabVIEW and C# which can talk to C API's directly.
For output parameters, the choice was fairly obvious. An output struct containing a const string pointer and a length makes the most sense. Its easy to use these from most other languages, and doesn't require special null termination handling. Freeing these is also easy, as if you ever receive one of these string structures, theres just a single function call to free it.
Input parameters are a bit more complex. To be used from pure C, and from LabVIEW, a null terminated string is the best in most cases. However, null terminated strings in general have a lot of downsides. Additionally, from LabVIEW there are other considerations around encoding that having a wrapper struct helps make a bit easier. From a language like C#, a wrapper struct is by far the easiest, as custom marshalling can make it trivial to marshal both UTF8 and UTF16 strings down.
The final consideration is its nice to have an identical concept for both input and output. It makes the rules fairly easy to understand.
WPILib will not have any APIs that manipulate a string allocated externally. This means WPI_String can be const, as across the boundary it is always const.
If a WPILib API takes a const WPI_String*, WPILib will not manipulate or attempt to free that string, and that string is treated as an input. It is up to the caller to handle that memory, WPILib will never hold onto that memory longer than the call.
If a WPILib API takes a WPI_String*, that string is an output. WPILib will allocate that API with WPI_AllocateString(), fill in the string, and return to the caller. When the caller is done with the string, they must free it with WPI_FreeString().
If an output struct contains a WPI_String member, that member is considered read only, and should not be explicitly freed. The caller should call the free function for that struct.
If an array of WPI_Strings are returned, each individual string is considered read only, and should not be explicitly freed. The free function for that array should be called by the caller.
If an input struct containing a WPI_String, or an input array of WPI_Strings is passed to WPILib, the individual strings will not be manipulated or freed by WPILib, and the caller owns and should free that memory.
Callbacks also follow these rules. The most common is a callback either getting passed a const WPI_String* or a struct containing a WPI_String. In both of these cases, the callback target should consider these strings read only, and not attempt to free them or manipulate them.
DataLog is now a base class, with DataLogBackgroundWriter being the
background thread version and DataLogWriter being a non-threaded version.
Also split the C header into a separate file to make it more wpiformat friendly.
We now use a wrapper (wpi::print) to catch exceptions since we can't patch
std::print() to not throw when we ultimately migrate to it.
fmtlib and std format/print throw the same exceptions and always have. We previously patched fmt::print() to not throw a write failure exception, but we can't do that for std::print(); wpi::print() is the migration plan.
LTVUnicycleController is a drop-in replacement with better tuning knobs.
The RamseteCommand examples were removed instead of retrofitted with
LTVUnicycleController because we're planning on removing the command
controller classes anyway, so it would be wasted effort. The
SimpleDifferentialDriveSimulation example shows direct
LTVUnicycleController usage.
The default state for the DS in the simulated HAL is changed to disconnected.
The FMS view is now only editable in DS disconnected state.
This enables more robot and field-like testing of robot code, as the
alliance color and other parameters start in invalid states and are
only set when the DS connects.
