Move a red square around with the arrow keys.

sdl-test.c

#include "SDL2/SDL.h"
#include <stdio.h>


void clear(SDL_Renderer * renderer) {
    SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
    SDL_RenderClear(renderer);
    SDL_RenderPresent(renderer);
}

void draw(SDL_Renderer * renderer, SDL_Rect * rect) {
    SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
    SDL_RenderFillRect(renderer, rect);
    SDL_RenderPresent(renderer);
}

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

    SDL_Window *window;
    SDL_Renderer *renderer;

    SDL_Init(SDL_INIT_VIDEO);

    window = SDL_CreateWindow(
        "An SDL2 window",
        SDL_WINDOWPOS_UNDEFINED,
        SDL_WINDOWPOS_UNDEFINED,
        640,
        480,
        SDL_WINDOW_OPENGL
    );

    if (window == NULL) {
        printf("Could not create window: %s\n", SDL_GetError());
        return 1;
    }

    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);

    if (renderer == NULL) {
        printf("Could not create window: %s\n", SDL_GetError());
        return 1;
    }

    SDL_Rect rectangle = {
       .x = 10,
       .y = 10,
       .w = 10,
       .h = 10
    };

    clear(renderer);

    int quit = 0;
    while (!quit) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_KEYDOWN) {
                // Handle arrow keys
                switch(event.key.keysym.scancode) {
                    case SDL_SCANCODE_LEFT:
                        rectangle.x -= 10;
                        break;
                    case SDL_SCANCODE_RIGHT:
                        rectangle.x +=10;
                        break;
                    case SDL_SCANCODE_UP:
                        rectangle.y -= 10;
                        break;
                    case SDL_SCANCODE_DOWN:
                        rectangle.y += 10;
                        break;
                    default:
                        break;
                }

            } else if (event.type == SDL_QUIT) {
                quit = 1;
                puts("QUIT!");
                break;
            }
        }

        clear(renderer);
        draw(renderer, &rectangle);
    }

    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

Quero passar este repositório para meu android para testar sua funcionalidade no meu app Cxx, posso?

The SDL_RenderPresent(renderer); call at line 8 causes the square to flicker. By removing that line, the flickering is also gone.