Another small filled circe sub (not as fast as fcirc)

[bplus]

I like FC3 modified this way...

Code: (Select All)

Sub fc3 (cx, cy, r, clr~&)

    Line (cx - r, cy)-(cx + r, cy), clr~&, BF

    r2 = r * r

    Do

        x = Sqr(r2 - y * y)

        Line (cx - x, cy + y)-(cx + x, cy + y), clr~&, BF

        Line (cx - x, cy - y)-(cx + x, cy - y), clr~&, BF

        y = y + 1

    Loop Until y = r

End Sub

I favor the SQR() method as it was what I ran with in the flat ellipse project. I did have to use _INTEGER64 for the non-x and non-y variables to get uniform results with various ellipse sizes. I don't know if a circle fill would have similar/same size issues. I also recall something a bit off with QB64 SQR() while doing string math, where complex calculations differed a bit from online calculator sources. I'm not quite sure where that info was documented. The flat ellipse stuff in in the thread: https://qb64forum.alephc.xyz/index.php?topic=1044.0

BTW - I've speed tested my modification. It won twice and lost once. There is no definitive way of knowing, so I'm going with what I consider the best looping process, unless otherwise proven definitively incorrect. I can picture Steve wringing his
hands as I speak!

Pete

2 problems with your code:
1) overlapping lines, 3 are drawn actually, at the equator y = 0
2) you exit before y gets drawn with 2 lines at the r value

All is fixed by this!

Code: (Select All)

Screen _NewImage(800, 600, 32)
_ScreenMove 200, 50
fc3 400, 300, 290, _RGB32(0, 0, 255, 100) ' <<<< shows no overlapping lines at equator NOW

Sleep

Sub fc3 (cx, cy, r, clr~&)
    Line (cx - r, cy)-(cx + r, cy), clr~&, BF ' this line gets y = 0
    r2 = r * r
    Do
        ' you would do y = 0 2 more times unless you increase y first thing into loop
        y = y + 1 ' do y + 1 first!!! so y reaches r and draws 2 lines, then quits!
        x = Sqr(r2 - y * y)
        Line (cx - x, cy + y)-(cx + x, cy + y), clr~&, BF
        Line (cx - x, cy - y)-(cx + x, cy - y), clr~&, BF
    Loop Until y = r
End Sub