@lduboeuf
Thank you for your response. I ran "clickable create" and entered this option:
[7] main-cpp - C++/QML App (built using CMake with a main.cpp)
My project name is "mytest". I ran "clickable" and my USB connected tablet running Ubuntu Touch shows the app with "Hello World!". Good!

Next, I changed the main.cpp file so that is has the SDL test C++ code that you see in this posting. Also, I tried to make changes to the clickable.json file so the dependencies can be met, like so:

{
"template": "cmake",
"dir": "build/app",
"libraries": {
"SDL2": {
"template": "cmake"
}
},
"dependencies_target": [
"libsdl2-dev"
]
}

I saw clickable downloading the SDL2 files for armhf architecture. Looked good. But I get these error messages:

[ 90%] Linking CXX executable mytest
CMakeFiles/mytest.dir/main.cpp.o: In function main': main.cpp:(.text+0xc): undefined reference toSDL_Init'
main.cpp:(.text+0x2e): undefined reference to `SDL_CreateWindow'
etc...

What should I adjust to get this test SDL test program working? Thanks!

I've written some programs in C++ and SDL and would like to publish them to the UT app store. UT seems to lack documentation for how to do this with C++ and SDL. Clickable seems to work great with qml but I don't see any support or documentation for C++/SDL.

Below is a basic "Hello World" C++ program that compiles and works great on Ubuntu Desktop. It just displays a red screen and quits after 5 seconds. Can someone please provide step-by-step documentation on how to make this test program run on Ubuntu Touch? Either by using clickable or Cmake? If someone can be so kind as to document how, it will make it easy for other developers to contribute SDL apps to the UT store.

Thank you!!!

---------------- Contents of main.cpp:

#include <SDL2/SDL.h>

int main(int argc, char *argv[])
{
SDL_Init(SDL_INIT_VIDEO);
SDL_Window *window = SDL_CreateWindow( "SDL2Test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 1280, 720, 0 );
SDL_SetWindowFullscreen( window, SDL_TRUE );
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_SOFTWARE);
SDL_SetRenderDrawColor(renderer, 255, 0, 0, SDL_ALPHA_OPAQUE);
SDL_RenderClear(renderer);
SDL_RenderPresent(renderer);
SDL_Delay(5000);
SDL_DestroyWindow(window);
SDL_Quit();

return 0;
}

---------------- From the terminal:

g++ -o test main.cpp -lSDL2
./test

Here's the source of the main.cpp:

#include <SDL.h>

int main(int argc, char *argv[])
{
SDL_Init(SDL_INIT_VIDEO);

SDL_Window *window = SDL_CreateWindow( "SDL2Test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0 );

SDL_SetWindowFullscreen( window, SDL_TRUE );

SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_SOFTWARE);
SDL_SetRenderDrawColor(renderer, 255, 0, 0, SDL_ALPHA_OPAQUE);
SDL_RenderClear(renderer);
SDL_RenderPresent(renderer);

SDL_Delay(5000);

SDL_DestroyWindow(window);
SDL_Quit();

return 0;
}

Thanks to all for your input and suggestions so far. I ran searches online for "CMakeLists.txt SDL tutorial", and read many tutorials. This is what I have so far that seems to almost work:

1. sudo apt install libsdl2-dev
   clickable create
   I chose option [7] main-cpp - C++/QML App (built using CMake with a main.cpp)

2. I replaced the main.cpp file in my project directory with a very small 512 byte SDL test program. It just produces a blank screen for 5 seconds and then quits. I compiled and tested it with the Code::Blocks IDE and it works fine there.

3. I added these lines to my CMakeLists.txt file in my project directory and finally I got it to link up with the SDL library:
   add_executable(${PROJECT_NAME} main.cpp)
   find_package(SDL2 REQUIRED)
   include_directories(${SDL2_INCLUDE_DIRS})
   set(SDL2_LIBRARIES "-lSDL2")
   target_link_libraries(${PROJECT_NAME} ${SDL2_LIBRARIES})

4. I run clickable from my project directory and it compiles the program just fine and sends it to my Ubuntu Touch tablet where I see the logo.svg flash on the screen for only 1 second. Finally, no error messages not being able to link up with SDL. However, I don't get the expected blank screen for 5 seconds. The logo.svg shows on the screen along with my project name for only 1 second, but it seems to quit before running the program which should show a blank screen for 5 seconds. On my tablet I now have the logo.svg icon displayed as one of my apps. When I click on it the icon shows along with the app name for about 1 second and then closes.

Does anyone know what I need to tweak to get SDL to run on UT through clickable? Then, like Wendigo said, we will have a working SDL recipe for UT/clickable for other app developers.

I've written a program in C++ and SDL2 and would like to publish it to the Ubuntu Touch open store. I have installed clickable and I've gotten the "Hello World" screen on my tablet. I added the SDL dependencies to the clickable.json file.

Could someone be kind enough to tell me how/where to put my C++ files and what settings to make in the CMakeLists.txt file? I have four .cpp and four .h files. I wont need to use Qml.

When I run clickable it almost compiles, but it appears to not be able to link to the SDL libraries.

Thanks!