What is this?

This is a project that makes it possible to program in C++ in FTC. This is also 100% competition legal cause it still uses the SDK, it just accesses it from C++ via the Java Native Interface (JNI).

Advantages

Faster execution (Exact data from the Test Results)
No forced object orientation
Compiler statements
Access to OpenCV as a native library
Access to other C++ libraries
You can still use Java and use this project just as an extension

Disadvantages

Not every feature from the SDK is included yet
More difficult debugging
No access to Java libraries such as Roadrunner

Who should use this?

As you see above as a rookie team I wouldn't suggest you to use this. It is rather designed for more experienced teams who want to try something new and who want to push their software to the limit to get the best loop times possible.

Downloading this project

To download this repository, simply run the following command in your terminal:

git clone https://github.com/flemmii/FTCpp-SDK.git

After cloning you need to execute the build process once so after that everything is set up and you can download the code normally to your robot. Also after a clean you need to execute the build process once before downloading. (This will get changed later)

Also make sure that you have node installed, otherwise download it here

Remember you need to merge this repository into your own repository to get the latest updates.

Excluding the example from downloading

If you don't want the example to be downloaded to your repository ever time you pull you can you can just run this command in the root of your project:

git update-index --assume-unchanged TeamCode/src/main/cpp/teamcode/header/example.h
git update-index --assume-unchanged TeamCode/src/main/cpp/teamcode/sources/example.cpp

The different folders

You can find these folders in TeamCode/src/main/cpp

createOpModeJava

This folder contains two template files that are used to create the equivalent OpMode in Java. It also has the JavaScript file that creates the files in Java.

You do not need to do anything in this folder.

external_libraries

This folder contains the external libraries that are used in the project:

The sources of these projects are already included by the FTC SDK.

If you want to add any of other libraries put the header files in there.

sdk

This folder contains the C++ framework of the SDK that is used to communicate with the robot controller.

You can add your own sensors, motors or whatever you need. If you do so it'd be nice if you could open a pull request on GitHub to share your code with others.

teamcode

This module, teamcode, is the place where you will write/paste the code for your team's robot controller App. This module has currently only one example but the process for adding OpModes is straightforward.

Creating your own OpModes

The easiest way to create your own OpMode is to copy a Example OpMode and make it your own.

But if you want to create a new OpMode from scratch you can use the following steps:

Create a new file in the header folder with the name of your OpMode
Create a new file in the source folder with the name of your OpMode
Add the following code to the header file:

#include <jni.h>
#include "sdk.h"

// Your OpMode annotation shown below
    
extern "C" void Example();

Add the following code to the source file:

extern "C" void Example() {
    // Your code here
}

Change the path to your OpMode by just changing the Java_org_firstinspires_ftc_teamcode_opmodes_teleop_Example_opMode to your path.
- The penultimate part of the path is the name of the Java file and Class
- The last part is the name of the method in there

Annotations

You got the same annotations as in Java, the only difference is that they need to be in a comment in you header file of your OpMode in the header folder.

 @TeleOp(name="Example", group="Example")
 @Disabled

The name that will appear on the driver station's "opmode list" is defined by the code: name="Template: Linear OpMode" You can change what appears between the quotes to better describe your opmode. The "group=" portion of the code can be used to help organize your list of OpModes.

As shown, the current OpMode will NOT appear on the driver station's OpMode list because of the @Disabled annotation which has been included. This line can simply be deleted to make the OpMode visible.

Changing the folder structure

If you want to move your header to another folder simply head to the createOpModeJava/index.js file and change the folder name in line 36 to the path of your desire. Also change the path in the CMakelists.txt in line 70 to the same path.

If you want to move your sources to another folder you just need to change the path in the CMakelists.txt in line 18 to the path of your desire.

Troubleshooting

You can always open an issue on GitHub or write me on Discord (flemmii) if you have any problems. But please try to solve the problem yourself first.

Build fails

You get normal error messages in the terminal, so you can see what went wrong.

Code crashes on robot

You can only see the errors in logcat, so nothing will be shown on the Driver Hub. If you want to log anything additional to logcat simply include the sdk/extras/utils.h file and use the log function.

<details close> <summary> How a log looks like </summary> <span style="color:Red"> JNI DETECTED ERROR IN APPLICATION: JNI NewGlobalRef called with pending exception java.lang.IllegalArgumentException: Unable to find a hardware device with name "test" and type DcMotorEx at java.lang.Object com.qualcomm.robotcore.hardware.HardwareMap.get(java.lang.Class, java.lang.String) (HardwareMap.java:213) at void org.firstinspires.ftc.teamcode.opmodes.autonomous.AutoTest.opMode() (AutoTest.java:-2) at void org.firstinspires.ftc.teamcode.opmodes.autonomous.AutoTest.runOpMode() (AutoTest.java:15) at void com.qualcomm.robotcore.eventloop.opmode.LinearOpMode.internalRunOpMode() (LinearOpMode.java:199) at void com.qualcomm.robotcore.eventloop.opmode.OpModeInternal.lambda$internalInit$1$com-qualcomm-robotcore-eventloop-opmode-OpModeInternal() (OpModeInternal.java:181) at void com.qualcomm.robotcore.eventloop.opmode.OpModeInternal$$ExternalSyntheticLambda1.run() (D8$$SyntheticClass:-1) at void com.qualcomm.robotcore.util.ThreadPool.logThreadLifeCycle(java.lang.String, java.lang.Runnable) (ThreadPool.java:737) at void com.qualcomm.robotcore.eventloop.opmode.OpModeInternal.lambda$internalInit$2$com-qualcomm-robotcore-eventloop-opmode-OpModeInternal() (OpModeInternal.java:179) at void com.qualcomm.robotcore.eventloop.opmode.OpModeInternal$$ExternalSyntheticLambda2.run() (D8$$SyntheticClass:-1) at void java.util.concurrent.ThreadPoolExecutor.runWorker(java.util.concurrent.ThreadPoolExecutor$Worker) (ThreadPoolExecutor.java:1133) at void java.util.concurrent.ThreadPoolExecutor$Worker.run() (ThreadPoolExecutor.java:607) at void com.qualcomm.robotcore.util.ThreadPool$ThreadFactoryImpl$1.run() (ThreadPool.java:793) at void java.lang.Thread.run() (Thread.java:761) in call to NewGlobalRef from void org.firstinspires.ftc.teamcode.opmodes.autonomous.AutoTest.opMode() "OpModeThread" prio=5 tid=58 Runnable | group="main" sCount=0 dsCount=0 obj=0x137fc280 self=0x782599e200 | sysTid=3589 nice=0 cgrp=default sched=0/0 handle=0x781fdf0450 | state=R schedstat=( 0 0 0 ) utm=106 stm=2 core=2 HZ=100 | stack=0x781fcee000-0x781fcf0000 stackSize=1037KB | held mutexes= "mutator lock"(shared held) native: #00 pc 000000000047ef3c /system/lib64/libart.so (_ZN3art15DumpNativeStackERNSt3__113basic_ostreamIcNS0_11char_traitsIcEEEEiP12BacktraceMapPKcPNS_9ArtMethodEPv+220) native: #01 pc 000000000047ef38 /system/lib64/libart.so (_ZN3art15DumpNativeStackERNSt3__113basic_ostreamIcNS0_11char_traitsIcEEEEiP12BacktraceMapPKcPNS_9ArtMethodEPv+216) native: #02 pc 0000000000452fc4 /system/lib64/libart.so (_ZNK3art6Thread9DumpStackERNSt3__113basic_ostreamIcNS1_11char_traitsIcEEEEbP12BacktraceMap+480) native: #03 pc 00000000002f04a4 /system/lib64/libart.so (_ZN3art9JavaVMExt8JniAbortEPKcS2_+1136) native: #04 pc 00000000002f0bb4 /system/lib64/libart.so (_ZN3art9JavaVMExt9JniAbortVEPKcS2_St9__va_list+124) native: #05 pc 0000000000102798 /system/lib64/libart.so (_ZN3art11ScopedCheck6AbortFEPKcz+156) native: #06 pc 00000000001021a8 /system/lib64/libart.so (_ZN3art11ScopedCheck11CheckThreadEP7_JNIEnv+536) native: #07 pc 00000000000ffce8 /system/lib64/libart.so (_ZN3art11ScopedCheck5CheckERNS_18ScopedObjectAccessEbPKcPNS_12JniValueTypeE+1124) native: #08 pc 0000000000103a7c /system/lib64/libart.so (_ZN3art8CheckJNI6NewRefEPKcP7_JNIEnvP8_jobjectNS_15IndirectRefKindE+624) native: #09 pc 0000000000014648 /data/app/com.qualcomm.ftcrobotcontroller-1/lib/arm64/libsdk.so (_ZN7_JNIEnv12NewGlobalRefEP8_jobject+40) native: #10 pc 000000000001c7f0 /data/app/com.qualcomm.ftcrobotcontroller-1/lib/arm64/libsdk.so (_ZN3sdk12hardware_map3getEP7_jclassRKNSt6__ndk112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEE+236) native: #11 pc 0000000000070f04 /data/app/com.qualcomm.ftcrobotcontroller-1/lib/arm64/libteamcode.so (Java_org_firstinspires_ftc_teamcode_opmodes_autonomous_AutoTest_opMode+3036) native: #12 pc 000000000011e230 /data/app/com.qualcomm.ftcrobotcontroller-1/oat/arm64/base.odex (Java_org_firstinspires_ftc_teamcode_opmodes_autonomous_AutoTest_opMode__+124) </span> </details>  

This looks like a lot but if you look at specific lines you can find out where the issue is. The last

FTCpp

Install / Use

README