General Description
This program has been designed to allow the user to rotate a 3-D prism on the screen. You can create your own prism by altering the data statement in line 2000 (see detailed notes below).
Detailed Description
Lines 5 and 60 First part of delete trick.
10-50 Display title.
70-90 Asks for number of sides to that prism, e.g. a square prism has four sides.
Ask for size to display on screen.
Ask for steps, (this is for rotation).
Note: Validation is not carried out on the above inputs because the user can modify the data line.
100-110 Displays the page giving list of instructions.
120 Converts angle from degrees to radians.
130-180 Sets up variables and reads data for prism.
190 Transfer shape through Z-plane.
200-290 Display each end of prism.
300-360 This is the procedure to transfer shape along Z-plane by two units. (At line 340)
370-410 Join both ends of prism together.
420-570 Get input from keyboard.
580-650 Rotates about Y-axis using rotation matrix.
X' = X COS Q - Z SIN Q
Z' = Z COS Q - X SIN Q
Y' = Y
660-730 Rotates about X-axis using matrix.
X' = X
Y' = Y COS Q + Z SIN Q
Z' = Z COS Q - X SIN Q
740-810 Rotate about Z-axis using matrix.
X' = X COS Q + Y SIN Q
Y' = Y COS Q - X SIN Q
Z' = Z
820-970 Displays help page, and gives a list of instructions.
980-1050 Gives instructions.
1060-1067 Second part of delete trick.
1070-1120 Credits.
2000 Is the data for the prism.
Note: To change shape of prism, change line 2000. The data at line 2000 is in the format
| X,Y | , | X,Y | , | X,Y | , | X,Y |
| First corner | Second corner | Third corner | Fourth corner | |||
Educational Notes
Whilst this program has an obvious role in clarifying descriptions in geometry lesson, it's also a wonderful demonstration of the potential of computer graphics!