Subprograms

A Simple Comet

The purpose of this exercise is to animate the planets using subprograms.

Expected result

Question 1

Implement Compute_X and Compute_Y functions and use them in the main loop to update X and Y coordinates of every object.

Question 2

Implement the Move subprogram and use it to move the objects instead of doing all computations in the main loop.

Move should also update the angle.

Question 3

Implement a procedure Draw_Body which is a wrapper to call Draw_Sphere.

From the main loop call Draw_Body instead of directly drawing Draw_Sphere. Draw_Body should only take 2 parameters.

Question 4

Add a tail to the comet that rotates around the Sun.

Hint: Try adding a Has_Tail component to Body_T, then modifying Draw to display the tail properly.

Hint #2: An object that has a tail can be seen as being “followed” by small circles that are moved in the opposite direction from the body being drawn.