draw arcs with glcd

[stan cartwright]

This is a simple way of plotting part radius of a circle from start degree to end degree
values 0 to 359
xcentre of arc
ycentre of arc
xradius-distance from xcentre to xradius
yradius-distance from ycentre to yradius

#INCLUDE <TRIG2PLACES.H>
dim xcentre,ycentre,xradius,yradius,degrees,start_arc,end_arc as word
xcentre=120:ycentre=180:xradius=130:yradius=130:start_arc=0:end_arc=359
arc
end

sub arc
for degrees=start_arc to end_arc
  pset (xcentre+xradius*sin(degrees)/255,ycentre+yradius*cos(degrees)/255,ILI9341_YELLOW)
next
end sub

This code would plot a circle mid screen fast'
change xradius=100:yradius=140 and you get an eliptical circle.
change start_arc to 90 and end_arc to 270 and you get half the eliptical circle.
you can have any part of a circle or elipse positioned anywhere by changing the variables.
make those boxes curved corners or design guages.
I'll post a video later.
It is simple code but does what glcd can not as a command.

for count =0 to 359
xradius=count/2:yradius=count/2:start_arc=count:end_arc=count+1
arc
next

drew the image almost instant.The code is worth playing with if you are into gcb graphics and gcb trig works fast it seems.
expanding circle with wait 5 s to see it's a spiral not circles, https://www.youtube.com/watch?v=luowdg_HUUE

[stan cartwright]

No comments. gcb users only use 2 line displays.
gcb is fast enough to do nice graphics... but not a popular thing.
uno has
Flash 32k bytes (of which .5k is used for the bootloader)
SRAM 2k bytes
EEPROM 1k byte
that's plenty to play with.
a lot can be done without resorting to nextion...which can be made to look good but is serial 9600.
glcd and spi or parallel 8 bit port are so much faster. just needs a bit of imagination.
a bit of trig to design a screen would be used once but the gcb trig runs fast. dunno how much mem it uses but it's handy...if you remember learning trig.
no PI though.

edit trig was something I was taught but never found an application for
until graphics... on a cpc464 in z80 asm...and now 328p using basic,,sigh

[stan cartwright]

imho the hardware includes have been the best gcb improvements...but I use a 328
so the pic stuff improvements don't mean so much,
using glcd would be so difficult otherwise....memories of implementing
draw line on a picaxe with ssd 1306...interesting I suppose, if you have the time...
and the time it took to draw the line using picaxe.
Thanks to the authors of gcb includes.

drawing shapes like half circle could be filled using trig but adapting the glcd filled circle
might be better. dunno how to fill polygons.

[stan cartwright]

imho the hardware includes have been the best gcb improvements...but I use a 328
so the pic stuff improvements don't mean so much,
using glcd would be so difficult otherwise....memories of implementing
draw line on a picaxe with ssd 1306...interesting I suppose, if you have the time...
and the time it took to draw the line using picaxe.
Thanks to the authors of gcb includes.

drawing shapes like half circle could be filled using trig but adapting the glcd filled circle
might be better. dunno how to fill polygons. mid point something.