raylib dynamic camera window resizing

#include <raylib.h>
#define RAYGUI_IMPLEMENTATION
#include <raygui.h>
#include <stdint.h>
#include <iostream>
#include <vector>

const int DEFAULT_WIDTH = 800;
const int DEFAULT_HEIGHT = 600;


const int BOUNDS_ASSERTIONS = false;

static void todoImpl(uint64_t line, const char* file) {
    std::cerr << file << ":" << line << " is todo" << std::endl;
    exit(1);
}

#define TODO() \
    todoImpl(__LINE__, __FILE__)

void initWindow() {
    SetConfigFlags(FLAG_WINDOW_RESIZABLE | FLAG_VSYNC_HINT);
    InitWindow(DEFAULT_WIDTH, DEFAULT_HEIGHT, "sand experiment 3");
    BeginDrawing();
    {
        ClearBackground(BLACK);
        DrawText("Loading sand...", 10, 10, 20, RAYWHITE);
    }
    EndDrawing();
}

const int COLUMN_WIDTH = 800;
const int ROW_HEIGHT = 600;

// class Grid {
//     public:

//         std::vector<bool> cellIsSand = std::vector<bool>();
//         uint64_t grid_width = 0;
//         uint64_t grid_height = 0;

//         inline uint64_t cellPosV(Vector2 pos) {
//             uint64_t pos = (pos.y * COLUMN_WIDTH) + pos.x;
//             return pos;
//         }

//         inline bool cellHasSandV(Vector2 cellPos) {

//         }

//         inline Grid() {

//         }



// };

static int CAMERA_ZOOM = 1;
float screen_ratio(int current_size, int default_size) {
    return (float)current_size / (float)default_size;
}

int main() {

    initWindow();

    Rectangle menu_bounds = Rectangle{0, 0, COLUMN_WIDTH, 50};
    Rectangle sim_bounds = Rectangle {0, 60, COLUMN_WIDTH, ROW_HEIGHT-60};
    Camera2D camera = Camera2D {};
    camera.offset = Vector2{0, 60};
    camera.rotation = 0;
    camera.target = Vector2{0, 60};
    // camera.target = Vector2{COLUMN_WIDTH/2, ROW_HEIGHT/2};
    camera.zoom = 1;

    bool firstRun = true;
    while (!WindowShouldClose())
    {
        BeginDrawing();
        {
            ClearBackground(BLACK);

            DrawRectangleRec(menu_bounds, BROWN);
            for (int i = 0; i < 3; i++) {
                Rectangle bounds = menu_bounds;
                bounds.y += 5;
                bounds.x += 5;
                bounds.width = 50;
                bounds.height = 40;
                bounds.x = (60* i) + 10;
                GuiButton(bounds, "meow");

            }

            BeginMode2D(camera);
            {
                DrawRectangleRec(sim_bounds, GREEN);
            }
            EndMode2D();
        }
        EndDrawing();

        // update camera if window resized
        if (IsWindowResized() || firstRun) {
            int new_h = GetScreenHeight();
            int new_w = GetScreenWidth();

            float ratio_h = screen_ratio(new_h, ROW_HEIGHT); // (float)new_h / (float)HEIGHT;
            float ratio_w = screen_ratio(new_w, COLUMN_WIDTH); // (float)new_w / (float)WIDTH;

            // smallest ratio means window is smallest along that dimension
            if (ratio_w < ratio_h) {
                camera.zoom = ratio_w * 0.99;
            } else {
                camera.zoom = ratio_h * 0.99;
            }

            CAMERA_ZOOM = camera.zoom;
        }

        PollInputEvents();

        firstRun = false;
    }

    CloseWindow();
}