用c语言写一个美观的轮播图，功能性要强

由于轮播图需要图形界面支持，因此需要使用相应的图形库。以下是使用SDL2图形库实现的一个简单的美观的轮播图示例代码：

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

#define WINDOW_WIDTH 800
#define WINDOW_HEIGHT 600
#define IMAGE_WIDTH 400
#define IMAGE_HEIGHT 300
#define IMAGE_X (WINDOW_WIDTH - IMAGE_WIDTH) / 2
#define IMAGE_Y (WINDOW_HEIGHT - IMAGE_HEIGHT) / 2

int main(int argc, char* argv[])
{
    SDL_Window* window = NULL;
    SDL_Renderer* renderer = NULL;
    SDL_Texture* texture1 = NULL;
    SDL_Texture* texture2 = NULL;
    SDL_Event event;

    int quit = 0;
    int current_image = 0;
    int next_image = 1;

    SDL_Init(SDL_INIT_VIDEO);

    window = SDL_CreateWindow("轮播图", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_SHOWN);
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);

    SDL_Surface* surface1 = SDL_LoadBMP("image1.bmp");
    texture1 = SDL_CreateTextureFromSurface(renderer, surface1);
    SDL_FreeSurface(surface1);

    SDL_Surface* surface2 = SDL_LoadBMP("image2.bmp");
    texture2 = SDL_CreateTextureFromSurface(renderer, surface2);
    SDL_FreeSurface(surface2);

    while (!quit)
    {
        while (SDL_PollEvent(&event) != 0)
        {
            if (event.type == SDL_QUIT)
            {
                quit = 1;
            }
        }

        SDL_RenderClear(renderer);

        if (current_image == 0)
        {
            SDL_RenderCopy(renderer, texture1, NULL, &(SDL_Rect){ .x = IMAGE_X, .y = IMAGE_Y, .w = IMAGE_WIDTH, .h = IMAGE_HEIGHT });
        }
        else
        {
            SDL_RenderCopy(renderer, texture2, NULL, &(SDL_Rect){ .x = IMAGE_X, .y = IMAGE_Y, .w = IMAGE_WIDTH, .h = IMAGE_HEIGHT });
        }

        SDL_RenderPresent(renderer);

        SDL_Delay(2000);

        current_image = next_image;
        next_image = (next_image + 1) % 2;
    }

    SDL_DestroyTexture(texture1);
    SDL_DestroyTexture(texture2);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);

    SDL_Quit();

    return 0;
}

该程序使用SDL2图形库创建了一个窗口，并在窗口中显示了两张图片，每隔2秒切换一次图片。可以通过添加更多的图片和更复杂的切换动画实现更美观、更具功能性的轮播图。