Graphical User Interfaces - Pro Unity Game Development with C# - page 258

 Lines 9-15. The pixel padding class specifies the amount of padding to be
added onto an anchor to offset the GUI onto the screen into its desired position.
Though the member is called pixel padding , the value is specified in relative
terms (using normalized values, between 0 and 1), as shown in Figure 8-2 . The
word pixel in the title emphasizes that, whatever relative values are used, the
values ultimately resolve to pixel values, depending on the screen resolution.
 Lines 27 and 28. Here, two member variables are added to indicate the
anchoring for the GUI control on both the horizontal and vertical axes. Left or
Right , and Top and Bottom . Thus, to anchor this GUI object to the screen's
top-left, HorzAlign should be Left , and VertAlign should be Top .
 Lines 45-60. The Update function calculates the position of the control, based
on its anchoring and padding values, as well as the orthographic size of the GUI
camera, ensuring the object is positioned and scaled correctly on screen.
To put our newly coded GUI object into practice, let's begin work on creating the game's main menu.
Right now, we don't have all the code we need—after all, we'll need additional code to actually
render the menu on-screen using sprites. But, right now, we have some core relative-positioning
functionality to get us started. For the menu, create a new object in the scene, taking care to add it
to a GUI layer and to assign the GUICamera field to the GUICamera object in the scene. And then
add a GUIObject component to it. For CMOD, the menu graphic should be centered on-screen.
Therefore, HorzAlign should be Left , VertAlign should be Top. Left Padding should be 0.5 , and
Top Padding should be 0.5 (see Figure 8-3 ). In the next section, Figure 8-4 displays the complete
menu graphic.
Figure 8-4. The main menu background graphic (559×549 pixels), to be positioned at screen center (0.5, 0.5)