Improved my small Gradient Ball drawing SUB

[bplus]

_HYPOT huh?  Neat.  I shouldn't have stopped reading the keyword of the day thread.  

- 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!!!