SDL学习

今天简单学习一了一下SDL库的使用代码如下：

#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include <SDL2/SDL_image.h>
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
SDL_Window *window;
SDL_Renderer *renderer;
TTF_Font *font;
TTF_Font *font1;
TTF_Font *font2;
int init(void)
{
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) < 0)
    {
        printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    window = SDL_CreateWindow("实时时钟", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
    if (!window)
    {
        printf("Window could not be created! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    if (!renderer)
    {
        printf("Renderer could not be created! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    if (TTF_Init() == -1)
    {
        printf("TTF could not initialize! SDL_ttf Error: %s\n", TTF_GetError());
        return -1;
    }
    font = TTF_OpenFont("/usr/share/fonts/truetype/wqy/wqy-zenhei.ttc", 36);
    font1 = TTF_OpenFont("/usr/share/fonts/truetype/wqy/wqy-zenhei.ttc", 96);
    font2 = TTF_OpenFont("/usr/share/fonts/truetype/wqy/wqy-zenhei.ttc", 48);
    TTF_SetFontHinting(font, TTF_HINTING_LIGHT);
    TTF_SetFontHinting(font1, TTF_HINTING_LIGHT);
    TTF_SetFontHinting(font2, TTF_HINTING_LIGHT);
    if (!font)
    {
        printf("Failed to load font! SDL_ttf Error: %s\n", TTF_GetError());
        return -1;
    }
    return 0;
}
char *getFormattedDateTime(void)
{
    time_t rawtime;
    struct tm *timeinfo;
    static char buffer[80];
    time(&rawtime);
    timeinfo = localtime(&rawtime);
    strftime(buffer, sizeof(buffer), "%H:%M:%S", timeinfo);
    return buffer;
}
char *getFormattedDate(void)
{
    time_t rawtime;
    struct tm *timeinfo;
    static char buffer[80];
    time(&rawtime);
    timeinfo = localtime(&rawtime);
    strftime(buffer, sizeof(buffer), "%Y年%m月%d日", timeinfo);
    return buffer;
}
void renderText(const char *text, int x, int y, TTF_Font *f, SDL_Color textColor)
{
    SDL_Surface *textSurface = TTF_RenderUTF8_Solid(f, text, textColor);
    SDL_Texture *textTexture = SDL_CreateTextureFromSurface(renderer, textSurface);
    SDL_Rect textRect = {x, y, textSurface->w, textSurface->h};
    SDL_RenderCopy(renderer, textTexture, NULL, &textRect);
    SDL_FreeSurface(textSurface);
    SDL_DestroyTexture(textTexture);
}
int main(int argc, char *args[])
{
    if (init() != 0)
    {
        return -1;
    }
    int quit = 0;
    SDL_Event e;
    int windowWidth, windowHeight;
    SDL_Surface *backgroundSurface = NULL;
    SDL_Texture *backgroundTexture = NULL;
    SDL_GetWindowSize(window, &windowWidth, &windowHeight);
    if ((backgroundSurface = IMG_Load("./x.jpg")) == NULL)
    { // 请替换为你的图片路径
        printf("无法加载背景图片: %s\n", IMG_GetError());
        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
    }
    else
    {
        backgroundTexture = SDL_CreateTextureFromSurface(renderer, backgroundSurface);
        SDL_FreeSurface(backgroundSurface);
    }
    while (!quit)
    {
        while (SDL_PollEvent(&e) != 0)
        {
            if (e.type == SDL_QUIT)
            {
                quit = 1;
            }
        }
        SDL_RenderClear(renderer);
        if (backgroundTexture)
        {
            SDL_RenderCopy(renderer, backgroundTexture, NULL, NULL);
        }
        char *dateTimeStr = getFormattedDateTime();
        SDL_Color dateTimeColor = {255, 255, 255, 255}; // 白色
        renderText(dateTimeStr, 100, 160, font1, dateTimeColor);                                      // 假设在左上角显示
        dateTimeStr = getFormattedDate();
        SDL_Color dateColor = {0, 0, 255, 255}; // 蓝色
        renderText(dateTimeStr, 30, 10, font, dateColor);
        SDL_Color greetingColor = {255, 0, 0, 255}; // 红色
        renderText((char *)"大家好", windowWidth - 200, windowHeight - 100, font2, greetingColor); // 在右下角显示问候语
        // 注意:阴历显示需额外实现,这里省略
        SDL_RenderPresent(renderer);
        SDL_Delay(1000); // 每秒更新一次
    }
    TTF_CloseFont(font);
    TTF_Quit();
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

编译代码：

gcc -I/usr/include/x86_64-linux-gnu/ -o clock  clock.c -lSDL2 -lSDL2_ttf -lSDL2_image  &&./clock