Qt OpenGLWidgetでQOpenGLContext::doneCurrent()を実装する：レンダリング終了とコンテキスト切り替えの実践例

Qt GUIにおけるQOpenGLContext::doneCurrent()の解説

QOpenGLContext::doneCurrent()は、Qt GUIアプリケーションにおいてOpenGLコンテキストを非アクティブ化するための関数です。これは、OpenGLレンダリングを終了し、別のコンテキストに切り替える準備ができたことを示します。

使用方法

QOpenGLContext::doneCurrent()を呼び出すには、以下のコード例のように、呼び出し側スレッドで現在アクティブなコンテキストを指定する必要があります。

QOpenGLContext::currentContext()->doneCurrent();

注意点

• QOpenGLContext::doneCurrent()を呼び出す前に、QOpenGLContext::swapBuffers()を呼び出して描画バッファをスワップする必要があります。
• QOpenGLContext::doneCurrent()を呼び出すと、OpenGLコンテキストに関連するすべてのOpenGLリソースが解放されます。
• マルチスレッド環境では、各スレッドで個別のOpenGLコンテキストを使用する必要があります。

例

以下のコード例は、QOpenGLWidgetサブクラスでpaintGL()関数内にQOpenGLContext::doneCurrent()を呼び出す方法を示しています。

void MyOpenGLWidget::paintGL()
{
    // OpenGLレンダリングを行う

    // 描画バッファをスワップする
    swapBuffers();

    // OpenGLコンテキストを非アクティブ化する
    doneCurrent();
}

補足

• QOpenGLContext::doneCurrent()は、OpenGLコンテキストを共有グループから解放します。共有グループ内の他のコンテキストは引き続きアクティブなままになります。
• QOpenGLContext::doneCurrent()は、OpenGLコンテキストを削除しません。コンテキストを削除するには、deleteLater()またはdelete()を呼び出す必要があります。

QOpenGLContext::doneCurrent()は、Qt GUIアプリケーションにおいてOpenGLレンダリングを終了し、別のコンテキストに切り替える重要な関数です。この関数を正しく使用することで、OpenGLリソースを効率的に管理し、アプリケーションのパフォーマンスを向上させることができます。

For instance, if you're looking for examples of using QOpenGLContext::doneCurrent() in Qt, I could provide the code snippet from the previous response again. If you're interested in a different programming language or framework, please let me know.

I can also provide examples for various tasks, such as:

• Data manipulation: sorting, filtering, aggregating, and transforming data
• Web scraping: extracting information from websites
• Machine learning: training and using machine learning models
• Natural language processing: text summarization, sentiment analysis, and machine translation

Please provide more details about your specific needs, and I'll do my best to assist you.

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