The window whose callback to set.
The new callback, or null to remove the currently set callback.
The previously set callback, or null if no callback was set or the library had not been initialized.
@callback_signature
void function_name(GLFWwindow* window, float xscale, float yscale)
For more information about the callback parameters, see the function pointer type.
Errors: Possible errors include @ref GLFW_NOT_INITIALIZED.
This function must only be called from the main thread.
@sa @ref window_scale @sa @ref glfwGetWindowContentScale
Added in version 3.3.
Ingroup: window
Sets the window content scale callback for the specified window.
This function sets the window content scale callback of the specified window, which is called when the content scale of the specified window changes.