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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):
Reply
#22
playing about with this last night, no claims of "improvement". A wee bit of interaction with key presses.
Code: (Select All)
'v bubbles
'$dynamic
Screen _NewImage(800, 600, 32)

Dim Shared Points: Points = 50
Dim Shared PointX(Points), PointY(Points), PointR(Points), PointG(Points), PointB(Points)
Randomize Timer

For p = 1 To Points
    PointX(p) = Rnd * _Width
    PointY(p) = Rnd * _Height
    PointR(p) = 50 + Rnd * 60
    PointG(p) = 60 + Rnd * 80
    PointB(p) = 70 + Rnd * 100
Next
wr = 4 'wiggle ratio
Do
    _Limit 50000 'experiment with the value that works for you and keeps your computer from metling
    For p = 1 To Points
        PointX(p) = PointX(p) + Rnd * wr - Rnd * wr
        PointY(p) = PointY(p) + Rnd * wr - Rnd * wr
        PointR(p) = PointR(p) + Rnd * 3 - Rnd * 3
        PointG(p) = PointG(p) + Rnd * 3 - Rnd * 3
        PointB(p) = PointB(p) + Rnd * 3 - Rnd * 3
    Next
    For y = 0 To _Height Step 4 'skipping points of calcualtion to speed things along
        For x = 0 To _Width Step 4
            min = Sqr((x - PointX(1)) ^ 2 + (y - PointY(1)) ^ 2)
            closest = 1
            For p = Points To 2 Step -1

                dis = Sqr((x - PointX(p)) ^ 2 + (y - PointY(p)) ^ 2)
                If dis < min Then
                    min = dis
                    closest = p
                End If
            Next
            'circlefill? Yes circle fill because it's quicker in getting that screen filled
            CircleFill x, y, 3, _RGB(PointR(closest) - min, PointG(closest) - min, PointB(closest) - min)

        Next
    Next
    kk$ = InKey$
    Select Case (kk$)
        Case "C", "c" 'change the pattern
            For p = 1 To Points
                PointX(p) = Rnd * _Width
                PointY(p) = Rnd * _Height
                PointR(p) = 50 + Rnd * 60
                PointG(p) = 60 + Rnd * 80
                PointB(p) = 70 + Rnd * 100
            Next
        Case "<", "," 'slower wiggle
            wr = wr - .5
            If wr < 0 Then wr = 0
        Case ">", "." 'quicker wiggle
            wr = wr + .5
        Case "R" 'more red
            For p = 1 To Points
                PointR(p) = PointR(p) + (1 + Rnd * 6)
            Next
        Case "r" 'less red
            For p = 1 To Points
                PointR(p) = PointR(p) - (1 + Rnd * 6)
            Next 'more green
        Case "G"
            For p = 1 To Points
                PointG(p) = PointG(p) + (1 + Rnd * 6)
            Next
        Case "g" 'less green
            For p = 1 To Points
                PointG(p) = PointG(p) - (1 + Rnd * 6)

            Next
        Case "B" 'more blue
            For p = 1 To Points
                PointB(p) = PointB(p) + (1 + Rnd * 6)
            Next
        Case "b" 'less blue
            For p = 1 To Points
                PointB(p) = PointB(p) - (1 + Rnd * 6)
            Next
        Case "M" 'more points
            Points = Points + 1
            ReDim _Preserve PointX(Points), PointY(Points), PointR(Points), PointG(Points), PointB(Points)
            PointX(Points) = Rnd * _Width
            PointY(Points) = Rnd * _Height
            PointR(Points) = 50 + Rnd * 60
            PointG(Points) = 60 + Rnd * 80
            PointB(Points) = 70 + Rnd * 100
        Case "m" 'less points
            If Points > 20 Then
                Points = Points - 1
                ReDim _Preserve PointX(Points), PointY(Points), PointR(Points), PointG(Points), PointB(Points)
            End If

    End Select
    _Display
Loop Until kk$ = Chr$(27)
Sub CircleFill (CX As Integer, CY As Integer, R As Integer, C As _Unsigned Long)
    ' CX = center x coordinate
    ' CY = center y coordinate
    '  R = radius
    '  C = fill color
    Dim Radius As Integer, RadiusError As Integer
    Dim X As Integer, Y As Integer
    Radius = Abs(R)
    RadiusError = -Radius
    X = Radius
    Y = 0
    If Radius = 0 Then PSet (CX, CY), C: Exit Sub
    Line (CX - X, CY)-(CX + X, CY), C, BF
    While X > Y
        RadiusError = RadiusError + Y * 2 + 1
        If RadiusError >= 0 Then
            If X <> Y + 1 Then
                Line (CX - Y, CY - X)-(CX + Y, CY - X), C, BF
                Line (CX - Y, CY + X)-(CX + Y, CY + X), C, BF
            End If
            X = X - 1
            RadiusError = RadiusError - X * 2
        End If
        Y = Y + 1
        Line (CX - X, CY - Y)-(CX + X, CY - Y), C, BF
        Line (CX - X, CY + Y)-(CX + X, CY + Y), C, BF
    Wend
End Sub
Reply
#23
I like it, James!  Neat wiggle motion.  Seems to update quickly too.  I'll have to study that a while.  Thanks for sharing.

I was playing around this morning with adding a plasms texture to the gradient ball.  Here's a growing plasma ball.  Had to use the STEP/LINE trick to make it faster - PSETing it was too slow on my laptop.

- Dav

Code: (Select All)

'Growing Plasma ball
'by Dav, JULY/2023

SCREEN _NEWIMAGE(1000, 650, 32)

x = _WIDTH / 2 'x place of ball
y = _HEIGHT / 2 ' y place of ball
size = 45 'ball start size


DO
    t = TIMER
    FOR y2 = y - size TO y + size STEP 3
        FOR x2 = x - size TO x + size STEP 3
            IF SQR((x2 - x) ^ 2 + (y2 - y) ^ 2) <= size THEN
                clr = (size - (SQR((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y)))) / size
                noise = INT(RND * 75)
                r = SIN(6.005 * t) * size - y2 + size + 255
                g = SIN(3.001 * t) * size - x2 + size + 255
                b = SIN(2.001 * x2 / size + t + y2 / size) * r + 255
                LINE (x2, y2)-STEP(2, 2), _RGBA(clr * r - noise, clr * g - noise, clr * b - noise, 5 + RND * 10), BF
            END IF
        NEXT
        t = t + .01
    NEXT
    IF size < y THEN size = size + .5
    _LIMIT 60
    _DISPLAY
LOOP



EDIT:  A little variation - ball grows & shrinks randomly, leaving gassy like edges. Looks less like a ball.

Code: (Select All)

SCREEN _NEWIMAGE(1000, 650, 32)

x = _WIDTH / 2 'x place of ball
y = _HEIGHT / 2 ' y place of ball
size = 45 'ball start size


DO
    t = TIMER
    FOR y2 = y - size TO y + size STEP 3
        FOR x2 = x - size TO x + size STEP 3
            IF SQR((x2 - x) ^ 2 + (y2 - y) ^ 2) <= size THEN
                clr = (size - (SQR((x2 - x) * (x2 - x) + (y2 - y) * (y2 - y)))) / size
                noise = INT(RND * 50)
                r = SIN(6.005 * t) * size - y2 + size + 255
                g = SIN(3.001 * t) * size - x2 + size + 255
                b = SIN(2.001 * x2 / size + t + y2 / size) * r + 255
                LINE (x2, y2)-STEP(2, 2), _RGBA(clr * r - noise, clr * g - noise, clr * b - noise, 5 + RND * 10), BF
            END IF
        NEXT
        t = t + .01
    NEXT

    LINE (0, 0)-(_WIDTH, _HEIGHT), _RGBA(0, 0, 0, 10), BF

    IF INT(RND * 2) = 1 THEN size = size + (RND * 15) ELSE size = size - (RND * 15)
    IF size < y THEN size = size + .5
    IF size > (y * 1.5) THEN size = y
    IF size < 15 THEN size = 15

    _LIMIT 60
    _DISPLAY
LOOP


Find my programs here in Dav's QB64 Corner
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