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asknik2022
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Joined: 26/03/2022
Location: United Kingdom
Posts: 94

Posted: 05:08pm 03 Mar 2023

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OPTION BASE 1

'Define color lookup table

DIM rgb%(4,3)
rgb%(1,1)=255: rgb%(1,2)=255: rgb%(1,3)=0 'YELLOW
rgb%(2,1)=255: rgb%(2,2)=0: rgb%(2,3)=0 'RED
rgb%(3,1)=0: rgb%(3,2)=0: rgb%(3,3)=255 'BLUE
rgb%(4,1)=0: rgb%(4,2)=128: rgb%(4,3)=0 'GREEN
'Set up the Spirograph parameters
r1 = 90
r2 = 30
p = 60
colorindex =0
'Set up the rotation parameters
cx = 120
cy = 160
angle = 0
angle_step = 0.5

CLS

DO
getcol
sa = SIN(angle)
ca = COS(angle)
'Calculate the Spirograph path
FOR t = 0 TO 360 STEP 1
a = (r1-r2)/r2
x = (r1-r2)*COS(t) + p*COS(a*t)
y = (r1-r2)*SIN(t) - p*SIN(a*t)

'Rotate the coordinates and draw a pixel
xp = cx + INT(x*ca - y*sa)
yp = cy + INT(x*sa + y*ca)
Pixel xp,yp,rgb(rgb%(colorindex,1),rgb%(colorindex,2),rgb%(colorindex,3))

NEXT t
' Update the angle and wait a bit before redrawing
angle = angle + angle_step

LOOP

sub getcol
' Set color
colorindex=int(rnd*3)+1
end sub

homa

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Joined: 05/11/2021
Location: Germany
Posts: 496

Posted: 08:36pm 03 Mar 2023

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cx = 120
cy = 160

switch to

cy = 120
cx = 160

and add at the beginning

mode 2
Edited 2023-03-04 06:38 by homa

asknik2022
Regular Member

Joined: 26/03/2022
Location: United Kingdom
Posts: 94

Posted: 08:04am 04 Mar 2023

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This is for the picomite and the screen was set to portrait ili9341

homa

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Joined: 05/11/2021
Location: Germany
Posts: 496

Posted: 11:26am 04 Mar 2023

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asknik2022 said This is for the picomite and the screen was set to portrait ili9341

Ah, sorry. I use the PicoMiteVGA.

Andrew_G
Guru

Joined: 18/10/2016
Location: Australia
Posts: 873

Posted: 05:22am 05 Mar 2023

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@asknik,
G'day and a belated "welcome" to the forum.
A nice program, thanks. It is one of those things I enjoyed in my youth and it is good to now see it in MMBasic.
I've fiddled with r1 & r2 (as well as Cx and Cy).
I'll add it to the programs for my grandchildren.

Cheers,

Andrew

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