This is a variation on the Space Donuts sample program that adds force-feedback output if a force-feedback joystick is installed in your computer.
Source: (SDK root)\Samples\Multimedia\DInput\Src\FFdonuts
Executable: (SDK root)\Samples\Multimedia\DInput\Bin
When the program is started, you see a dialog box that lets you set the magnitude of the force feedback effects.
When your ship appears, move the joystick forward to accelerate forward and pull it back to decelerate or move backward. Moving the joystick left or right rotates the ship. Press the trigger button to fire. Press the second button to activate the shields. Observe the force feedback effects as you fire, collide with objects, and bounce off the edge of the screen.
The force feedback routines are in Input.c. The program illustrates the use of constant and periodic effects, envelopes, and gain. Note that the fire-button effect is played in response to an ordinary input event rather than being associated with a trigger button in the DIEFFECT structure.