FFmpeg06：SDL渲染

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于 2025-09-15 18:06:02 发布 · 908 阅读

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#ffmpeg

SDL介绍

SDL(Simple DirectMedia Layer)
由C语言实现的跨平台的媒体开源库
多用于游戏、模拟器、媒体播放器等多媒体应用领域

SDL编译与安装

拉取源码
先切换分支为SDL2
执行autogen.sh生成configure （可不执行）
生成Makefile: configure --prefix=/usr/local
安装sudo make -j 8 && sudo make install

SDL使用

头文件#include<SDL.h>
初始化SDL
退出SDL

渲染窗口

SDL_Init/SDL_Quit()
SDL_CreateWindow()/ SDL_DestoryWindow()
SDL_CreateRender()/SDL_DestoryRender()
SDL_RenderClear
SDL_RenderPresent

#include <SDL.h>

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

    SDL_Window* window = SDL_CreateWindow("hello sdl", 200, 200, 640, 470, SDL_WINDOW_SHOWN);
    SDL_Renderer* render;
    SDL_Event event;
    if (!window) {
   
   
        printf("Failed to create window: %s\n", SDL_GetError());
        goto __EXIT;
    }

    render = SDL_CreateRenderer(window, -1, 0);
    if (!render) {
   
   
        printf("Failed to create renderer: %s\n", SDL_GetError());
        goto __EXIT;
    }
      
    SDL_PollEvent(&event); // 没有事件处理就不会显示窗口

    SDL_SetRenderDrawColor(render, 255, 10, 0, 255); // 必须在RenderClear之前设置颜色

    SDL_RenderClear(render);

    SDL_RenderPresent(render);  // 显示

    SDL_Delay(300000);


__EXIT:
    SDL_DestroyRenderer(render);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}

事件基本原理

SDL将所有事件都存放在一个队列中
所有对事件的操作，其实就是对队列的操作

事件种类

SDL_WindowEvent：窗口事件
SDL_KeyboardEvent：键盘事件
SDL_MouseMotionEvent：鼠标事件

事件处理

SDL_PollEvent：轮询检测队列
SDL_WaitEvent：事件触发机制

#include <SDL.h>

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

    SDL_Window* window = SDL_CreateWindow("hello sdl", 200, 200, 640, 470, SDL_WINDOW_SHOWN);
    SDL_Renderer* render;
    SDL_Event event;
    int quit = 1;
    if (!window) {
   
   
        printf("Failed to create window: %s\n", SDL_GetError());
        goto __EXIT;
    }

    render = SDL_CreateRenderer(window, -1, 0);
    if (!render) {
   
   
        printf("Failed to create renderer: %s\n", SDL_GetError());
        goto __EXIT;
    }
      
    // SDL_PollEvent(&event); // 没有事件处理就不会显示窗口

    SDL_SetRenderDrawColor(render, 255, 10, 0, 255); // 必须在RenderClear之前设置颜色

    SDL_RenderClear(render);

    SDL_RenderPresent(render);  // 显示

    do {
   
   
        SDL_WaitEvent(&event);
        switch (event.type)
        {
   
   
        case SDL_QUIT:
            quit = 0;
            break;
        
        default:
            SDL_Log("event type: %d", event.type);
            break;
        }
        
    } while(quit);

    // SDL_Delay(300000);


__EXIT:
    SDL_DestroyRenderer(render);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}