基于OpenGL渲染相机流鸿蒙示例代码

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介绍

本示例基于OpenGL对相机流进行处理操作，然后通过Xcomponen渲染显示相机，实现相机的录制、播放视频功能。

基于OpenGL渲染相机流源码链接

效果预览

使用说明

使用OpenGL的相关能力，需要添加相关动态链接库和头文件。

实现思路

1. 添加XComponent组件，在native侧通过OH_NativeXComponent_RegisterCallback注册XComponent回调；

    // 调用触摸事件回调
    renderCallback_.DispatchTouchEvent = DispatchTouchEventCB;
    OH_NativeXComponent_RegisterCallback(nativeXComponent, &renderCallback_);

2. 在napi 接口init的时候在Xcomponent的OnSurfaceCreatedCB回调中初始化渲染线程，通过OH_NativeImage_Create创建nativeImage；

void OnSurfaceCreatedCB(OH_NativeXComponent *component, void *window)
{
    OH_LOG_Print(LOG_APP, LOG_INFO, LOG_PRINT_DOMAIN, "Callback", "OnSurfaceCreatedCB");
    if ((component == nullptr) || (window == nullptr)) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, LOG_PRINT_DOMAIN, "Callback",
                     "OnSurfaceCreatedCB: component or window is null");
        return;
    }

    char idStr[OH_XCOMPONENT_ID_LEN_MAX + 1] = { '\0' };
    uint64_t idSize = OH_XCOMPONENT_ID_LEN_MAX + 1;
    if (OH_NativeXComponent_GetXComponentId(component, idStr, &idSize) != OH_NATIVEXCOMPONENT_RESULT_SUCCESS) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, LOG_PRINT_DOMAIN, "Callback",
                     "OnSurfaceCreatedCB: Unable to get XComponent id");
        return;
    }

    std::string id(idStr);
    auto render = PluginRender::GetInstance(id);
    uint64_t width;
    uint64_t height;
    int32_t xSize = OH_NativeXComponent_GetXComponentSize(component, window, &width, &height);
    if ((xSize != OH_NATIVEXCOMPONENT_RESULT_SUCCESS) || (render == nullptr)) {
        OH_LOG_Print(LOG_APP, LOG_ERROR, LOG_PRINT_DOMAIN, "Callback",
                     "OnSurfaceCreatedCB: Unable to get XComponent size");
        return;
    }
    if (render != nullptr) {
        render->UpdateNativeWindow(window, width, height);
    }
}

3. 通过OH_NativeImage_GetSurfaceId获取surfaceID并传递到arkts侧；

    {
        std::lock_guard<std::mutex> lock(nativeImageSurfaceIdMutex_);
        nativeImageWindow_ = OH_NativeImage_AcquireNativeWindow(nativeImage_);
        ret = OH_NativeImage_GetSurfaceId(nativeImage_, &nativeImageSurfaceId_);
    }

4. 通过OH_NativeImage_SetOnFrameAvailableListener设置帧可用回调，通过NativeVsync接收系统信号，控制渲染；

    nativeImageFrameAvailableListener_.context = this;
    nativeImageFrameAvailableListener_.onFrameAvailable = &RenderThread::OnNativeImageFrameAvailable;
    ret = OH_NativeImage_SetOnFrameAvailableListener(nativeImage_, nativeImageFrameAvailableListener_);

5. 通过OH_NativeImage_UpdateSurfaceImage获取最新帧更新相关联的OpenGL ES纹理，通过eglSwapBuffers将纹理渲染上屏

    OH_NativeImage_AttachContext(nativeImage_, nativeImageTexId_);

    int32_t ret = OH_NativeImage_UpdateSurfaceImage(nativeImage_);