PhotonVision/photonlib-cpp-examples/src/main/cpp/examples/simaimandrange/include/DrivetrainSim.h

/**
 * Copyright (C) 2018-2020 Photon Vision.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <frc/geometry/Pose2d.h>
#include <frc/smartdashboard/Field2d.h>
#include <frc/geometry/Translation2d.h>
#include <frc/geometry/Rotation2d.h>
#include <frc/simulation/PWMSim.h>
#include <frc/simulation/DifferentialDrivetrainSim.h>
#include <frc/system/plant/LinearSystemId.h>
#include <frc/smartdashboard/SmartDashboard.h>
#include <units/angle.h>
#include <units/length.h>
#include <units/time.h>
#include <photonlib/SimVisionSystem.h>
#include <frc/DriverStation.h>
#include <frc/RobotController.h>

#pragma once

class DrivetrainSim {

    
public:

  DrivetrainSim(){
      simVision.AddSimVisionTarget(photonlib::SimVisionTarget(farTargetPose, 81.91_in, targetWidth, targetHeight));
      frc::SmartDashboard::PutData("Field", &field);
  }

  void update();

private:

    // Simulated Motor Controllers
    frc::sim::PWMSim leftLeader {0};
    frc::sim::PWMSim rightLeader {1};

    // Simulation Physics
    // Configure these to match your drivetrain's physical dimensions
    // and characterization results.  
    decltype(1_V / 1_mps)          kv = 1.98 * 1_V * 1_s / 1_m;
    decltype(1_V / 1_mps_sq)       ka = 0.2 * 1_V * 1_s * 1_s / 1_m;
    decltype(1_V / 1_rad_per_s)    kvAngular = 1.5 * 1_V * 1_s / 1_rad;
    decltype(1_V / 1_rad_per_s_sq) kaAngular = 0.3 * 1_V * 1_s * 1_s / 1_rad;

    const frc::LinearSystem<2, 2, 2> kDrivetrainPlant =
    frc::LinearSystemId::IdentifyDrivetrainSystem(kv, ka, kvAngular, kaAngular);

    frc::sim::DifferentialDrivetrainSim m_drivetrainSimulator{
        kDrivetrainPlant,
        2.0_ft,
        frc::DCMotor::CIM(2),
        8.0,
        6.0_in / 2,
        {0.001, 0.001, 0.0001, 0.1, 0.1, 0.005, 0.005}};

    // Simulated Vision System.
    // Configure these to match your PhotonVision Camera,
    // pipeline, and LED setup.
    units::degree_t camDiagFOV = 170.0_deg; // assume wide-angle camera
    units::degree_t camPitch = 15_deg; 
    units::meter_t camHeightOffGround = 24_in;
    units::meter_t maxLEDRange = 20_m; 
    int camResolutionWidth = 640; // pixels
    int camResolutionHeight = 480; // pixels
    double minTargetArea = 10; // square pixels

    photonlib::SimVisionSystem simVision {
                    "photonvision",
                    camDiagFOV,
                    camPitch,
                    frc::Transform2d{},
                    camHeightOffGround,
                    maxLEDRange,
                    camResolutionWidth,
                    camResolutionHeight,
                    minTargetArea};

    // See https://firstfrc.blob.core.windows.net/frc2020/PlayingField/2020FieldDrawing-SeasonSpecific.pdf page 208
    const units::meter_t targetWidth = 41.30_in - 6.70_in; 
    // See https://firstfrc.blob.core.windows.net/frc2020/PlayingField/2020FieldDrawing-SeasonSpecific.pdf page 197
    const units::meter_t targetHeight = 98.19_in - 81.19_in; // meters
    // See https://firstfrc.blob.core.windows.net/frc2020/PlayingField/LayoutandMarkingDiagram.pdf pages 4 and 5
    const units::meter_t tgtXPos = 54_ft;
    const units::meter_t tgtYPos = (27.0_ft / 2) - 43.75_in - (48.0_in / 2.0);
    const frc::Translation2d targetTrans {tgtXPos, tgtYPos};
    const frc::Rotation2d targetRot {0.0_deg};
    frc::Pose2d farTargetPose {targetTrans, targetRot};

    frc::Field2d field {};

};