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Improved my small Gradient Ball drawing SUB
#21
(07-12-2023, 02:36 PM)bplus Wrote:
(07-12-2023, 02:21 PM)Dav Wrote: _HYPOT huh?  Neat.  I shouldn't have stopped reading the keyword of the day thread. Rolleyes 

- Dav

Hi from ZXDunny at another forum that Charlie has inspired, this is a ball shader:
Code: (Select All)

' Ball shader
' by ZXDunny 2023

sw = 800
sh = 480
Screen _NewImage(sw, sh, 32) ' SpecBAS uses this as its default window size

xc = sw / 2
yc = sh / 2
r = 100
amb = 0.0125
k = 3
mxp = (1 - amb) * 255
r2 = r * r

Do
    While _MouseInput: Wend
    lx = xc - _MouseX
    ly = yc - _MouseY
    lz = -75

    Cls
    l = Sqr(lx * lx + ly * ly + lz * lz)
    nlx = lx / l
    nly = ly / l
    nlz = lz / l

    For x = -r To r
        x2 = x * x
        For y = -r To r
            y2 = y * y
            If x2 + y2 <= r2 Then
                v2 = Sqr(r2 - x2 - y2)
                l = Sqr(x2 + y2 + v2 * v2)
                v0 = x / l
                v1 = y / l
                v2 = v2 / l
                d = nlx * v0 + nly * v1 + nlz * v2

                'i = mxp * (iff(d < 0, -d ^ k, 0) + amb)
                If d < 0 Then i = mxp * (-d ^ k) + amp Else i = amp
                PSet (x + xc, y + yc), _RGB32(Int(i), Int(i), Int(i))
            End If
        Next y
    Next x
    _Display
Loop

The mouse is light source, so move it around...

More things to play with!!!

ZXDunny's BAM program (ULTIMATE Gradient Ball):
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Messages In This Thread
RE: Improved my small Gradient Ball drawing SUB - by CharlieJV - 07-12-2023, 09:30 PM



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