The snowboarder can jump over the trees and rocks.

We must detect the collisions between the snowboarder and the trees:

• We first test if the two objects are overlapping
• Then if the player lays in front of the tree (by comparing the vertical coordinates)
• Finally that the player is not jumping (with the Negate menu option).

When the player hits the obstacles all these conditions are true. One life is then subtracted from the number of lives and the frame is restarted.

We use the same logic to program the collision detection with the rocks. Notice that the events are identical.