main.cpp

#include <SDL2/SDL.h>
#include <emscripten/emscripten.h>
#include <iostream>

// GLOBAL APP STATE
struct AppState {
    SDL_Window* window;
    SDL_Renderer* renderer;
    int box_x = 100;
    int box_y = 100;
    int velocity = 2;
};

AppState app;

// ==========================================
// YOUR LOGIC GOES HERE (The Loop)
// ==========================================
void main_loop() {
    // 1. HANDLE EVENTS (Taps/Clicks)
    SDL_Event event;
    while (SDL_PollEvent(&event)) {
        if (event.type == SDL_MOUSEBUTTONDOWN) {
            // Reverse direction on tap
            app.velocity *= -1;
            std::cout << "Tap detected! Velocity is now " << app.velocity << std::endl;
        }
    }

    // 2. UPDATE STATE
    app.box_x += app.velocity;

    // Bounce off walls (assuming 800px width)
    if (app.box_x > 750 || app.box_x < 0) app.velocity *= -1;

    // 3. RENDER (Draw the Screen)
    // Clear screen to Black
    SDL_SetRenderDrawColor(app.renderer, 0, 0, 0, 255);
    SDL_RenderClear(app.renderer);

    // Draw Red Box
    SDL_Rect box = { app.box_x, app.box_y, 50, 50 }; // x, y, width, height
    SDL_SetRenderDrawColor(app.renderer, 255, 0, 0, 255);
    SDL_RenderFillRect(app.renderer, &box);

    // Show it
    SDL_RenderPresent(app.renderer);
}

// ==========================================
// SETUP (Do Not Touch)
// ==========================================
int main() {
    SDL_Init(SDL_INIT_VIDEO);
    SDL_CreateWindowAndRenderer(800, 600, 0, &app.window, &app.renderer);

    // Tell the browser to run "main_loop" infinitely
    emscripten_set_main_loop(main_loop, 0, 1);

    return 0;
}