advanced-user-manual2-en.md

Advanced User Manual 2: Create a window

Ash Engine has a high-level wrapper around Qt and OpenGL, and users without any OpenGL experience can easily create and render their own scenes.

Introduction

To create a window, you need to create three classes related to OpenGL rendering:

• OpenGLWindow: the window used for rendering (like drawing board)
• OpenGLRenderer: the renderer of OpenGL (like brush)
• OpenGLScene: the scene for rendering

Each OpenGLScene instance is associated with exactly one Scene instance. Scene maintains the tree structure of the entire scene, and OpenGLScene is used to manage OpenGL resources. In most cases, users only need to use Scene to manipulate the entire scene without worrying about the workings inside OpenGLScene.

Example

The following code shows how to create a window.

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

    QApplication a(argc, argv);

    // Step 1: Create an OpenGLWindow
    OpenGLWindow* window = new OpenGLWindow;
    window->resize(800, 600);

    // Step 2: Create an OpenGLRenderer for the window
    OpenGLRenderer* renderer = new OpenGLRenderer;
    window->setRenderer(renderer);

    // Step 3: Create a scene
    Scene* scene = new Scene;
    window->setScene(new OpenGLScene(scene));

    // Step 4: Customize your scene
    scene->addGridline(new Gridline);

    window->show();

    return a.exec();
}

Replace the main function in src/AshEngine.cpp with the above code, recompile and execute, you can get the following results: