Properties

Getting and setting GLFW window properties

Title

A window's title can be set using glfwSetWindowTitle(window,title), where title is a UTF-8 encoded string. It can be retrieved using glfwGetWindowTitle(window).

Position

The position of a windowed-mode window can be set with glfwSetWindowPos(window,xpos,ypos); xpos and ypos are integer values, describing at which screen coordinates the window's upper left corner should be positioned. The position can be retrieved using glfwGetWindowPos(window,xpos,ypos), where xpos and ypos are pointers to the variables you want the window position to be stored in (in Java normal variables have to be used, as there are no pointers). It is possible to set up a callback to get notified of positional changes.

Size

The size of a window can be set with glfwSetWindowSize(window,width,height); width and height have to be positive integer values, describing the window's size (including the titlebar, if visible) in screen coordinates. The size can be retrieved using glfwGetWindowSize(window,width,height), where width and height are pointers to the variables you want the window size to be stored in (in Java normal variables have to be used). For fullscreen windows, the specified values become the new resolution of the window's video mode; if the monitor's and the window's video mode differ, window contents may be displayed stretched or in a different unpleasant to watch manner. It is possible to set up a callback to get notified of size changes. You may prohibit the user from manually resizing the window using the GLFW_RESIZABLE creation hint.

To get the size of the display area for a window, excluding the titlebar and window frames, glfwGetWindowFrameSize(window,left,top,right,bottom) can be used. This returns the size of window decorations (if present); the size of the display subsequently can be calculated from the retrieved values. As above left, right, top, and bottom are pointers to variables; any of these parameters may be NULL.

Size Limits

The minimum and maximum size of a windowed-mode window can be enforced with glfwSetWindowSizeLimits(window,minwidth,minheight,maxwidth,maxheight); minwidth, minheight, maxwidth, and maxheight have to be positive integer values, describing the window limits in screen coordinates, or GLFW_DONT_CARE (default). These size limitations will not be applied until the window is resized, either by the user or by the program.

You may also want to enforce a specific aspect ratio, which you can do with glfwSetWindowAspectRatio(window,numer,denom); numer and denom specify the target aspect ratio as numerator and denominator. A 16:9 aspect ratio would be enforced as follows: glfwSetWindowAspectRatio(window,16,9). It is possible for aspect ratio and size limit to conflict, as described in the GLFW documentation.

Framebuffer Size

A window's framebuffer size can be retrieved directly using glfwGetFramebufferSize(window,width,height), or from a GLFWFramebufferSizeCallback (see Callbacks; width and height are again pointers, and describe the size of the window framebuffer in pixels. These values may differ from a window's size in screen coordinates, for example when the window is displayed on a high-DPI monitor.

Content Scale

Content scale can be used to correctly scale text and UI elements, for example in high-DPI environments. The ratio between the current DPI and the platform-default DPI can be retrieved with glfwGetWindowContentScale(window,xscale,yscale), where xscale and yscale are pointers to variables of type float. It is possible to set up a callback to get notified of scale changes. These values may change on the fly, when a system setting changes or the window is moved to a monitor with different scaling, for example.