Games at Bolton Scrolling Andrew Williams adw1

Games at Bolton scrollh  The first example simply scrolls horizontally –Look at screenRect in the program –Read the comments in the program

Games at Bolton scrollv  This is the equivalent of scrollh, only with vertical scrolling –Obviously, it is scrolling the “wrong way” –Again, screenRect is the key

Games at Bolton scrollhsprite1  Adding a sprite to the example  Although it looks right, it’s actually wrong.  The sprite is in screen space and the background scrolls in world space

Games at Bolton scrollhsprite2  This time, although it looks wrong, it is actually correct! –Both background and sprite live in the same coordinate system

Games at Bolton scrollhsprite3  In this version, we move the sprite in an attempt to “keep up with” the background –But is this the right approach?

Games at Bolton scrollhsprite4  This is probably more correct: –The sprite moves in world space –We move the “viewport” on the background as the sprite moves

Games at Bolton scrollhsprite5  If we use this approach, we can place other sprites in world space and wait for our sprite to encounter them

Games at Bolton scrollhsprite6  Simple control of the player’s sprite –Notice particularly the new, more complex approach to keyboard control This fixes the problems we’ve been having with the PS2

Games at Bolton scrollhsprite7  This time there is no automatic movement of the player’s sprite –We move forward using the right-arrow key –Whether this is what you want is up to you

Games at Bolton scrollhsprite8  Random location of the enemies –Look out for srand(...) and rand() The s stands for “seed”