Computer Science Canada

Spinning box

Author:  bryan_magnum [ Fri May 28, 2004 8:28 pm ]
Post subject:  Spinning box

How would i be able to make a box in turing and then make it spin in a circle, while spinning it gets bigger until it is the size of the screen?

Author:  AsianSensation [ Fri May 28, 2004 8:56 pm ]
Post subject: 

I see 2 ways.

Either use Pic.Rotate and Pic.Scale to change and rotate the picture of a box everytime in a loop. (not recommended, because Pic.Scale is really slow, and Pic.Rotate is not accurate)

A better way is to keep track of 4 points. Then use whatever math is needed to move those 4 points into their position, and then use drawpolygon.

Author:  bryan_magnum [ Fri May 28, 2004 9:28 pm ]
Post subject: 

how would i be able to make the four points spin and move out/ get bigger at the same time?

Author:  AsianSensation [ Fri May 28, 2004 9:35 pm ]
Post subject: 

you can represent any coordinate on the Cartesian Plane in polar form.

so have a variable call r, and theta.

each point could then be represented by (rcos (theta), rsin (theta)), where r is the magnitude of the vector (ie, how far it's from the center) and theta is the angle.

so you can have a loop, and increase theta every time, as well as your r. Make sure to start in the center of the screen, and make that your origin. The four points just have a difference in theta of 90.


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