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Here's a little screen saver showing pulsating orbs over a starry background with plasma clouds. I was playing around some old code, turned it into something new. Tested and runs OK under Windows and Linux.
- Dav
Code: (Select All)
'=============
'SpaceOrbs.bas
'=============
'Screensaver of Orbs pulsating in space
'Coded by Dav for QB64-PE, AUGUST/2023
RANDOMIZE TIMER
SCREEN _NEWIMAGE(1000, 640, 32)
'=== orb settings
orbs = 60 'number of orbs on screen
OrbSizeMin = 5 'smallest size an orb can get
OrbSizeMax = 60 'largest size an orb can get
DIM OrbX(orbs), OrbY(orbs), OrbSize(orbs), OrbGrowth(orbs)
'=== generate some random orb values
FOR i = 1 TO orbs
OrbX(i) = RND * _WIDTH 'x pos
OrbY(i) = RND * _HEIGHT 'y pos
OrbSize(i) = OrbSizeMin + (RND * (OrbSizeMax - OrbSizeMin)) 'orb size
OrbGrowth(i) = INT(RND * 2) 'way orb is changing, 0=shrinking, 1=growing
NEXT
'=== make a space background image
FOR i = 1 TO 100000
PSET (RND * _WIDTH, RND * _HEIGHT), _RGBA(0, 0, RND * 255, RND * 225)
NEXT
FOR i = 1 TO 1000
x = RND * _WIDTH: y = RND * _HEIGHT
LINE (x, y)-(x + RND * 3, y + RND * 3), _RGBA(192, 192, 255, RND * 100), BF
NEXT
'=== grab screen image for repeated use
back& = _COPYIMAGE(_DISPLAY)
DO
'=== place starry background first
_PUTIMAGE (0, 0), back&
'=== draw moving plasma curtain next
t = TIMER
FOR x = 0 TO _WIDTH STEP 3
FOR y = 0 TO _HEIGHT STEP 3
b = SIN(x / (_WIDTH / 2) + t + y / (_HEIGHT / 2))
b = b * (SIN(1.1 * t) * (_HEIGHT / 2) - y + (_HEIGHT / 2))
LINE (x, y)-STEP(2, 2), _RGBA(b / 3, 0, b, RND * 25), BF
NEXT: t = t + .085
NEXT
'=== now process all the orbs
FOR i = 1 TO orbs
'=== draw orb on screen
FOR y2 = OrbY(i) - OrbSize(i) TO OrbY(i) + OrbSize(i) STEP 3
FOR x2 = OrbX(i) - OrbSize(i) TO OrbX(i) + OrbSize(i) STEP 3
'make gradient plasma color
IF SQR((x2 - OrbX(i)) ^ 2 + (y2 - OrbY(i)) ^ 2) <= OrbSize(i) THEN
clr = (OrbSize(i) - (SQR((x2 - OrbX(i)) * (x2 - OrbX(i)) + (y2 - OrbY(i)) * (y2 - OrbY(i))))) / OrbSize(i)
r = SIN(6.005 * t) * OrbSize(i) - y2 + OrbSize(i) + 255
g = SIN(3.001 * t) * OrbSize(i) - x2 + OrbSize(i) + 255
b = SIN(2.001 * x2 / OrbSize(i) + t + y2 / OrbSize(i)) * r + 255
LINE (x2, y2)-STEP(2, 2), _RGBA(clr * r, clr * g, clr * b, 5 + RND * 15), BF
END IF
NEXT
NEXT
'=== change orb values
'if orb is shrinking, subtract from size, else add to it
IF OrbGrowth(i) = 0 THEN OrbSize(i) = OrbSize(i) - 1 ELSE OrbSize(i) = OrbSize(i) + 1
'if orb reaches maximum size, switch growth value to 0 to start shrinking now
IF OrbSize(i) >= OrbSizeMax THEN OrbGrowth(i) = 0
'if orb reaches minimum size, switch growth value to 1 to start growing now
IF OrbSize(i) <= OrbSizeMin THEN OrbGrowth(i) = 1
'creates the shakiness. randomly adjust x/y positions by +/-3 each
IF INT(RND * 2) = 0 THEN OrbX(i) = OrbX(i) + 3 ELSE OrbX(i) = OrbX(i) - 3
IF INT(RND * 2) = 0 THEN OrbY(i) = OrbY(i) + 3 ELSE OrbY(i) = OrbY(i) - 3
NEXT
_DISPLAY
_LIMIT 15
LOOP UNTIL INKEY$ <> ""
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Although I'm not that eager for this kind of stuff to be turned into screensavers...
Great work! It's making all the programmers of hundreds of raytracers blushing to match the grass!
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Mesmerizing. Cool!
New to QB64pe? Visit the QB64 tutorial to get started.
QB64 Tutorial
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Nice job!
Slowly scrolling the stars would create a parallax effect and would be a nice improvement.
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Thanks, ya'll for trying it. Yeah, scrolling stars would be a nice touch. Would have to change the alpha stuff to make it work. Will play with that idea.
- Dav
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I do not believe that I have seen anything like this... Either THIS example is very unique or it could be another proof that my ancient grey-matter is actually failing... Regardless... it is indeed VERY cool....
May your journey be free of incident. Live long and prosper.
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Thanks, @johnno56.
Adding the scrolling stars image presented a problem. Lost all the lazy-haze look to it because of the stars image draws. Had to resort to a _PUTIMAGE screen blur trick at the end to bring blurriness back somewhat. I prefer the old look, but moving stars does add another interest. Here's the new one with moving star background.
- Dav
Code: (Select All)
'=============
'SpaceOrbs2.bas
'=============
'Screesaver of Orbs pulsating in space
'Coded by Dav for QB64-PE, AUGUST/2023
'v2 - added scrolling stars background
' - orbs get new x/y position after shrinking away
' - had to change alpha values of plasma cloud and orbs,
' because of scrolling stars background. It's different.
' - Uses _PUTIMAGE screen trick to blur final _DISPLAY
Randomize Timer
Screen _NewImage(1000, 640, 32)
'=== orb settings
orbs = 60 'number of orbs on screen
OrbSizeMin = 5 'smallest size an orb can get
OrbSizeMax = 60 'largest size an orb can get
Dim OrbX(orbs), OrbY(orbs), OrbSize(orbs), OrbGrowth(orbs), OrbDir(orbs)
'=== generate some random orb values
For i = 1 To orbs
OrbX(i) = Rnd * _Width 'x pos
OrbY(i) = Rnd * _Height 'y pos
OrbSize(i) = OrbSizeMin + (Rnd * (OrbSizeMax - OrbSizeMin)) 'orb size
OrbGrowth(i) = Int(Rnd * 2) 'way orb is changing, 0=shrinking, 1=growing
OrbDir(i) = Int(Rnd * 4) 'random direction orb can drift (4 different ways)
Next
'=== make a space background image
For i = 1 To 100000
PSet (Rnd * _Width, Rnd * _Height), _RGBA(0, 0, Rnd * 255, Rnd * 225)
Next
For i = 1 To 1000
x = Rnd * _Width: y = Rnd * _Height
Line (x, y)-(x + Rnd * 3, y + Rnd * 3), _RGBA(192, 192, 255, Rnd * 175), BF
Next
'=== grab screen image for repeated use
back& = _CopyImage(_Display)
BackX = 0
Do
'=== scroll starry background first
_PutImage (BackX, 0)-(BackX + _Width, _Height), back&
_PutImage (BackX - _Width, 0)-(BackX, _Height), back&
BackX = BackX + 4: If BackX >= _Width Then BackX = 0
'=== draw moving plasma curtain next
t = Timer
For x = 0 To _Width Step 3
For y = 0 To _Height Step 3
b = Sin(x / (_Width / 2) + t + y / (_Height / 2))
b = b * (Sin(1.1 * t) * (_Height / 2) - y + (_Height / 2))
Line (x, y)-Step(2, 2), _RGBA(b / 3, 0, b, 50), BF
Next: t = t + .085
Next
'=== now process all the orbs
For i = 1 To orbs
'=== draw orb on screen
For y2 = OrbY(i) - OrbSize(i) To OrbY(i) + OrbSize(i) Step 3
For x2 = OrbX(i) - OrbSize(i) To OrbX(i) + OrbSize(i) Step 3
'make gradient plasma color
If Sqr((x2 - OrbX(i)) ^ 2 + (y2 - OrbY(i)) ^ 2) <= OrbSize(i) Then
clr = (OrbSize(i) - (Sqr((x2 - OrbX(i)) * (x2 - OrbX(i)) + (y2 - OrbY(i)) * (y2 - OrbY(i))))) / OrbSize(i)
r = Sin(6.005 * t) * OrbSize(i) - y2 + OrbSize(i) + 255
g = Sin(3.001 * t) * OrbSize(i) - x2 + OrbSize(i) + 255
b = Sin(2.001 * x2 / OrbSize(i) + t + y2 / OrbSize(i)) * r + 255
Line (x2, y2)-Step(2, 2), _RGBA(clr * r, clr * g, clr * b, 30 + Rnd * 25), BF
End If
Next
Next
'=== change orb values
'if orb is shrinking, subtract from size, else add to it
If OrbGrowth(i) = 0 Then OrbSize(i) = OrbSize(i) - 1 Else OrbSize(i) = OrbSize(i) + 1
'if orb reaches maximum size, switch growth value to 0 to start shrinking now
If OrbSize(i) >= OrbSizeMax Then OrbGrowth(i) = 0
'if orb reaches minimum size, switch growth value to 1 to start growing now
'and reset x/y pos
If OrbSize(i) <= OrbSizeMin Then
OrbGrowth(i) = 1
OrbX(i) = Rnd * _Width
OrbY(i) = Rnd * _Height
End If
'creates the shakiness. randomly adjust x/y positions by +/-3 each
If Int(Rnd * 2) = 0 Then OrbX(i) = OrbX(i) + 3 Else OrbX(i) = OrbX(i) - 3
If Int(Rnd * 2) = 0 Then OrbY(i) = OrbY(i) + 3 Else OrbY(i) = OrbY(i) - 3
'drift orb in 1 of 4 directions we generated, and +x,-x,+y,-y to it.
If OrbDir(i) = 0 Then OrbX(i) = OrbX(i) + 2 'drift right
If OrbDir(i) = 1 Then OrbX(i) = OrbX(i) - 2 'drift left
If OrbDir(i) = 2 Then OrbY(i) = OrbY(i) + 2 'drift down
If OrbDir(i) = 3 Then OrbY(i) = OrbY(i) - 2 'drift up
'below handles if ball goes off screen, let it dissapear completely
If OrbX(i) > _Width + OrbSize(i) Then OrbX(i) = -OrbSize(i)
If OrbX(i) < -OrbSize(i) Then OrbX(i) = _Width + OrbSize(i)
If OrbY(i) > _Height + OrbSize(i) Then OrbY(i) = -OrbSize(i)
If OrbY(i) < -OrbSize(i) Then OrbY(i) = _Height + OrbSize(i)
Next
'== screen blur trick to make it more misty looking
tmpback& = _CopyImage(_Display)
_SetAlpha 50, , tmpback&
_PutImage (-1, 0), tmpback&: _PutImage (1, 0), tmpback&
_PutImage (0, -1), tmpback&: _PutImage (0, 1), tmpback&
_PutImage (-1, -1), tmpback&: _PutImage (1, -1), tmpback&
_FreeImage tmpback&
_Display
_Limit 15
Loop Until InKey$ <> ""
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08-22-2023, 09:54 PM
Yes I like this 2nd version 
b = b + ...
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QBJS version with accidental shooting star effect:
(This is a good example to save for testing future performance enhancements.)
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Wow, the qbjs version looks even better to me.
By the way @dbox, you may use any of my posted stuff for your qbjs code examples if you want. qbjs is simply great.
- Dav
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