Задача №16
Управление точкой на экране.
uses graph,crt-
vargd,gm,x,y,x1,y1:integer-
— — — c:char-
label 0,1,2,3,4-
begin
initgraph(gd,gm,’c:\-bp\-bgi’)-
y:= 50-
x:= 50-
outtext(‘Press up,down, left ,right aroow keys for moving the point’)-
outtextxy(10,10,’PressEsc to Exit’)-
0:
c:=readkey-
if c=chr(27) thenhalt-
if ord(c)=72 thengoto 1-
if ord(c)=80 thengoto 2-
if ord(c)=75 thengoto 3-
if ord(c)=77 thengoto 4-
GOTO 0-
1:
y := y — 1-
IF y <- 1 THENy:= 2-
putpixel(x1, y1,0)-
putpixel(x, y, 15)-
x1 := x- y1 := y-
goto 0-
2:
putpixel(x, y, 0)-
y := y + 1-
IF y >- 479 THENy := 478-
putpixel (x1, y1,0)-
putpixel (x, y,15)-
x1 := x- y1 := y-
goto 0-
3:
x := x — 1-
IF x <- 1 THEN x:= 2-
putpixel(x1, y1,0)-
putpixel (x, y,15)-
x1 := x- y1 := y-
goto 0-
4:
x := x + 1-
IF x >- 639 THENx := 638-
putpixel (x1, y1,0)-
putpixel (x, y,15)-
x1:= x- y1 := y-
goto 0-
end.
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