2023-02-17：sdl是跨平台的多媒体开发库，请问用go语言如何调用？

2023-02-17：sdl是跨平台的多媒体开发库，请问用go语言如何调用？

答案2023-02-17：

用 github.com/moonfdd/sdl2-go 这个库。

这是我自己写的golang绑定sdl库，只依赖动态链接库，不依赖头文件，接口全部是按照头文件改过来的。

最好用sdl2里的接口，sdl3里的接口，运行有问题。

示例代码如下：

package main

import (
    "fmt"
    "io/ioutil"
    "time"
    "unsafe"

    sdl "github.com/moonfdd/sdl2-go/sdl2"
    "github.com/moonfdd/sdl2-go/sdlcommon"
)

const REFRESH_EVENT = sdl.SDL_USEREVENT + 1 // 请求画面刷新事件
const QUIT_EVENT = sdl.SDL_USEREVENT + 2    // 退出事件
//定义分辨率
// YUV像素分辨率
const YUV_WIDTH = 320
const YUV_HEIGHT = 240

//定义YUV格式
const YUV_FORMAT = sdl.SDL_PIXELFORMAT_IYUV

var s_thread_exit = 0 // 退出标志 = 1则退出

func main() {
    sdlcommon.SetSDL2Path("SDL2.0.16.dll")
    sdl.SDL_Init(sdl.SDL_INIT_VIDEO)
    pixformat := YUV_FORMAT
    // 分辨率
    // 1. YUV的分辨率
    video_width := int32(YUV_WIDTH)
    video_height := int32(YUV_HEIGHT)
    // 2.显示窗口的分辨率
    win_width := int32(YUV_WIDTH)
    win_height := int32(YUV_WIDTH)

    y_frame_len := video_width * video_height
    u_frame_len := video_width * video_height / 4
    v_frame_len := video_width * video_height / 4
    yuv_frame_len := y_frame_len + u_frame_len + v_frame_len

    window := sdl.SDL_CreateWindow("微信公众号：福大大架构师每日一题", sdl.SDL_WINDOWPOS_UNDEFINED, sdl.SDL_WINDOWPOS_UNDEFINED, video_width, video_height, sdl.SDL_WINDOW_OPENGL|sdl.SDL_WINDOW_RESIZABLE)
    if window == nil {
        fmt.Printf("Can't create window, err:%s", sdl.SDL_GetError())
        return
    }
    renderer := window.SDL_CreateRenderer(-1, 0)
    texture := renderer.SDL_CreateTexture(uint32(pixformat), sdl.SDL_TEXTUREACCESS_STREAMING, video_width, video_height)
    var event sdl.SDL_Event
    var rect sdl.SDL_Rect
    fileData, err := ioutil.ReadFile("yuv420p_320x240.yuv")
    if err != nil {
        fmt.Println("读取文件失败", err)
        return
    }
    //创建请求刷新线程
    go func() {
        for s_thread_exit == 0 {
            var event sdl.SDL_Event
            event.Type = REFRESH_EVENT
            event.SDL_PushEvent()
            time.Sleep(40 * time.Millisecond)
        }
        s_thread_exit = 0
        var event sdl.SDL_Event
        event.Type = QUIT_EVENT
        event.SDL_PushEvent()
    }()

    for {
        // 收取SDL系统里面的事件
        event.SDL_WaitEvent()
        if event.Type == REFRESH_EVENT { // 画面刷新事件
            if len(fileData) < int(yuv_frame_len) {
                break
            }
            video_buf := fileData[0:yuv_frame_len]
            for i := y_frame_len; i < yuv_frame_len; i++ {
                video_buf[i] = 128 //彩色变黑白
            }
            fileData = fileData[yuv_frame_len:]
            // 设置纹理的数据 video_width = 320， plane
            texture.SDL_UpdateTexture(nil, uintptr(unsafe.Pointer(&video_buf[0])), video_width)
            // 显示区域，可以通过修改w和h进行缩放
            rect.X = 0
            rect.Y = 0
            //w_ratio := win_width * 1.0 / video_width
            //h_ratio := win_height * 1.0 / video_height
            //// 320x240 怎么保持原视频的宽高比例
            //rect.W = video_width * w_ratio
            //rect.H = video_height * h_ratio
            rect.W = win_width
            rect.H = win_height

            // 清除当前显示
            renderer.SDL_RenderClear()
            // 将纹理的数据拷贝给渲染器
            renderer.SDL_RenderCopy(texture, nil, &rect)
            // 显示
            renderer.SDL_RenderPresent()

        } else if event.Type == sdl.SDL_WINDOWEVENT {
            window.SDL_GetWindowSize(&win_width, &win_height)
        } else if event.Type == sdl.SDL_QUIT {
            s_thread_exit = 1
        } else if event.Type == QUIT_EVENT {
            break
        }
    }
    texture.SDL_DestroyTexture()
    renderer.SDL_DestroyRenderer()
    window.SDL_DestroyWindow()
    sdl.SDL_Quit()
}

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