Rendering Cpp It’s basically a getter/setter for Window data. what it does is that you can update any data (typically a struct) eg.
// Update the title of the window
windowData.title = "New Window Title";
// Associate the updated data with the window
glfwSetWindowUserPointer(window, &windowData);
Then you can retrieve the data like:
WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);When you associate a user pointer with a GLFW window using glfwSetWindowUserPointer, you’re essentially telling GLFW, “Hey, here’s a pointer to some data that I want to associate with this window.” GLFW doesn’t monitor or manage the contents of that data; it simply stores the pointer internally. It can be updated anywhere then retrieved with glfwGetWindowUserPointer.
The user pointer in GLFW serves several purposes:
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Custom Data Association: It allows you to associate custom data or objects with GLFW windows. This can be extremely useful when you need to access specific application data or functionality within GLFW call-back functions, where you may not have direct access to other parts of your application.
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Context Passing: It provides a mechanism for passing context-specific information to GLFW call-back functions. For example, you might want to associate a unique identifier or additional metadata with each window, and the user pointer allows you to do this.
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State Management: It enables you to maintain state information related to GLFW windows. By associating a user pointer with each window, you can keep track of various window-specific properties or settings.
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Flexibility: It gives you flexibility in how you organize and manage your application’s data. You can use the user pointer to store pointers to complex data structures, objects, or even simple variables, depending on your application’s needs.
In summary, the user pointer in GLFW provides a way to associate custom data with windows, allowing you to manage state, pass context-specific information, and access application data within GLFW callback functions. This enhances the flexibility and extensibility of GLFW-based applications.