Frequently Asked Questions

Questions

1. No functionality for erasing a drawing is provided. How do I erase it?
2. Can I use turtle programming and sprite programming simultaneously in a single program?
3. How do I compile sprite program?
4. How do I compile turtle program?
5. Can I take turtlesim package for my home/hostel system?
6. Does turtlesim and graphicsim work on window, mac?
7. Which machines in OSL can be used for compiling sprite programs?
8. Sprite library does not allow to move two or more objects simultaneously. What is the work-around?

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Answers

1. No functionality for erasing a drawing is provided. How do I erase it?
   Erasing means drawing with background colour on top of existing drawing.
   
2. Can I use turtle programming and sprite programming simultaneously in a single program?
   No. You cannot.
   
3. How do I compile sprite program?
   Use following command.
   g++ file.cpp $SPRITE
   
4. How do I compile turtle program?
   Use following command.
   g++ file.cpp $TURTLE
   
5. Can I take turtlesim package for my home/hostel system?
   No. It requires lot of extra packages and system configuration.
   
6. Does turtlesim and graphicsim work on window, mac?
   No. Both of these packages are developed for linux only.
   
7. Which machines in OSL can be used for compiling sprite programs?
   Note that not every machine in OSL(Math building) is configured to compile sprite library. There are following few machines where sprite library is  installed. Use command ssh -X username@nsl-XX.cse.iitb.ac.in to log into those machines, where XX is machine number.

nsl-04	nsl-16	nsl-37	nsl-43	nsl-48	nsl-68	nsl-78	nsl-98
nsl-06	nsl-24	nsl-38	nsl-44	nsl-50	nsl-73	nsl-79	nsl-99
nsl-08	nsl-25	nsl-39	nsl-45	nsl-51	nsl-74	nsl-81	nsl-100
nsl-10	nsl-29	nsl-41	nsl-46	nsl-52	nsl-75	nsl-94
nsl-11	nsl-33	nsl-42	nsl-47	nsl-67	nsl-76	nsl-96


Advice: Choose some random machine from this list each time you log-in. You will be sharing machines with other students. If you feel that your machine is running slow, try some other machine.
8. Sprite library does not allow to move two or more objects simultaneously. What is the work-around?
   You cannot move two or more sprites simultaneously. But, your animation may demand such movements. There is an easy trick to simulate this. Move all sprites in small amount in round robin fashion. Check this psuedocode.
   

PSUEDO CODE:
// Let's assume that you want to move a line and polygon by 100 pixels towards right

for(iter = 0; iter < 100; iter += 10){
   line.move(10, 0);
   polygon.move(10, 0);
   // wait for some time to achieve animation effect
}