Launch rocket with countdown and acceleration in stdout: Difference between revisions

=={{header|REXX}}==

<lang rexx>/*REXX pgm does a countdown and then display the launching of a rocket (ASCII animation)*/

parse arg cntDown . /*obtain optional argument from the CL.*/

if cntDown=='' | cntDown=="," then cntDown= 5 /*Not specified? Then use the default.*/

@. = /* [↓] glyphs for the rocket ship. */

@.1= ' /\ '

@.2= ' | | '

@.3= ' | | '

@.4= ' | | '

@.5= ' /|/\|\ '

@.6= '/_||||_\'

do rs=1 while @.rs\=='' /*determine size of the rocket (height)*/

end /*rs*/

rs= rs - 1 /*the true rocket size (height). */

cls= 'CLS' /*the command used to clear the screen.*/

parse value scrsize() with sd sw .

sw= sw - 1 /*usable screen width on some systems. */

sd= sd - 3 /* " " depth " " " */

air= sd - 1 - rs /*"amount" of sky above the rocket. */

say

do j=cntDown by -1 to 1 /* [↓] perform countdown; show rocket.*/

cls /*use this command to clear the screen.*/

say right(j, 9) 'seconds' /*display the amount of seconds to go. */

call sky /*display the sky above the rocket. */

call rocket /*display the rocket (on the ground). */

call delay 1 /*wait one second during the countdown.*/

end /*j*/

say left('',9) "liftoff!" /*announce liftoff of the rocket. */

cls /*use this command to clear the screen.*/

call sky /*display the sky above the rocket. */

call rocket /*display the rocket (in flight). */

do sd+4; say /*"make" the rocket appear to fly. */

call delay .1 /*wait for one-tenth of a second. */

end /*sd+4*/

exit /*stick a fork in it, da rocket is gone*/

/*──────────────────────────────────────────────────────────────────────────────────────*/

sky: do air; say; end /*air*/; return /*display the sky above the rocket. */

rocket: do ship=1 for rs; say left('', sw%2 - 5) @.ship; end /*ship*/; return</lang>