Mandelbrot- What am I doning wrong?
BlitzMax Forums/BlitzMax Programming/Mandelbrot- What am I doning wrong?
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| I have tryed to update a BB3D mandelbrot routin. Something is screwed up...colors!!! Where are they? Can someone please help me? Here is the code: Strict AppTitle = "Mandelbrot" 'vars Global maxval:Float = 128.0 Global sx:Float = -2.025 Global sy:Float = -1.125 Global ex:Float = 0.6 Global ey:Float = 1.125 Global x1:Float = 640.0 Global y1:Float = 480.0 Global xy:Float = x1/y1 Global xstart:Float = sx Global ystart:Float = sy Global xend:Float = ex Global yend:Float = ey Global xzoom:Float = (xend - xstart) / x1 Global yzoom:Float = (yend - ystart) / y1 Global fac:Float = 0.99 'display Graphics x1,y1,0 xend = xend*fac xstart = xstart*fac yend = yend*fac ystart = ystart*fac xzoom = (xend - xstart) / x1 yzoom = (yend - ystart) / y1 mandelbrot() Flip() FlushMem() WaitKey End Function mandelbrot() Local x:Float Local y:Float Local h:Float Local old:Float Local b:Float For x = 0 To x1 - 1 For y = 0 To y1 - 1 h = DotCol(xstart + xzoom * x,ystart + yzoom * y) 'Print h If h <> old b = 1.0 - h * h HSB2RGB(h,0.8,b) old = h EndIf Plot x,y Next Next EndFunction Function DotCol(xval:Float,yval:Float) Local r:Float Local i:Float Local j:Float Local m:Float While (j < maxval) And (m < 4.0) j = j + 1 m = r * r - i * i i = 2.0 * r * i + yval r = m + xval Wend 'Print j 'j = j / maxval Return j EndFunction Function HSB2RGB(hue:Float,sat:Float,bri:Float) Local dof:Float Local red:Float Local green:Float Local blue:Float If bri = 0 Then SetColor 0,0,0 If sat = 0 Then SetColor bri*255,bri*255,bri*255 If hue < 1.0/6.0 dof = hue red = bri blue = bri * (1.0 - sat) green = blue + (bri - blue) * dof * 6.0 SetColor red*255,green*255,blue*255 Else If hue < 2.0/6.0 dof = hue - 1.0/6.0 green = bri blue = bri * (1.0 - sat) red = green - (bri - blue) * dof * 6.0 SetColor red*255,green*255,blue*255 Else If hue < 3.0/6.0 dof = hue - 2.0/6.0 green = bri red = bri * (1.0 - sat) blue = red + (bri - red) * dof * 6.0 SetColor red*255,green*255,blue*255 Else If hue < 4.0/6.0 dof = hue - 3.0/6.0 blue = bri red = bri * (1.0 - sat) green = blue - (bri - red) * dof * 6.0 SetColor red*255,green*255,blue*255 Else If hue < 5.0/6.0 dof = hue - 4.0/6.0 blue = bri green = bri * (1.0 - sat) red = green + (bri - green) * dof * 6.0 SetColor red*255,green*255,blue*255 Else dof = hue - 5.0/6.0 red = bri green = bri * (1.0 - sat) blue = red - (bri - green) * dof * 6.0 SetColor red*255,green*255,blue*255 EndIf EndIf EndIf EndIf EndIf EndFunction Regards Sveinung |
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| hue:4.00000000 sat:0.800000012 bri:-15.0000000 red:-15.0000000 grn:-2.99999976 blu:213.000000 hue:6.00000000 sat:0.800000012 bri:-35.0000000 red:-35.0000000 grn:-6.99999952 blu:832.999939 hue:8.00000000 sat:0.800000012 bri:-63.0000000 red:-63.0000000 grn:-12.5999994 blu:2104.20020 hue:128.000000 sat:0.800000012 bri:-16383.0000 red:-16383.0000 grn:-3276.59985 blu:9983801.00 your red and green values are all negative and the blue value way off the charts. 0 to 255 are the allow values. |
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| Definately something to do with the dotcol function. But you probably knew that already. |
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| HSV conversion should be simple enough. It starts off with the red at 255 and the others at 0. Green increases to 255. Then red falls to 0. Then blue increases to 255. Then green falls to 0. Then red increases to 255. Then blue falls to 0. At least that's what seems to happen. So you can indeed convert it to RBG using 6 steps, one each to handle each component going up or down. It should be simple. Maybe it'd be easier not to use floats? |
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| the hue never comes out less than 1, so the inner most else statement is the one that always gets executed. looks like anyway. |
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| @Indiepath.T Yes, I think you'r right and yes I know. But what I do not know. @Scott Shaver Any ideas why that happens? Here is the BB3D code
; Project: Mandelbrot - Speedtest
; Start: Tuesday, September 09, 2003
; Blitz3D - Linker Version 1.64
Global maxiter#=128 ; max iterations
SX# = -2.025 ; start value real
SY# = -1.125 ; start value imaginary
EX# = 0.6 ; End value real
EY# = 1.125 ; End value imaginary
x1# = 640 ; ScreenX
y1# = 480 ; ScreenY
xy# = x1# / y1#; x/y-ratio
Graphics 640, 480, 16, 2
xstart# = SX#
ystart# = SY#
xende# = EX#
yende# = EY#
xzoom# = (xende# - xstart#) / x1#
yzoom# = (yende# - ystart#) / y1#
fac#=0.999
SetBuffer BackBuffer()
While Not KeyDown(1)
Cls
xende# = xende#*fac#
xstart#=xstart#*fac#
ystart#=ystart#*fac#
yende#=yende#*fac#
xzoom# = (xende# - xstart#) / x1#
yzoom# = (yende# - ystart#) / y1#
mandelbrot(x1#, y1#, xstart#, ystart#, xzoom#, yzoom#)
Locate 0,0
thistime# = MilliSecs()
Print "Speed: " + Str$(Int(x1#*y1# / (1+(thistime#-lasttime#)))) + " Kpix/sec"
lasttime#=thistime#
Flip
Wend
End
; ------------------------------------------------------------- ;
; -=# Mandelbrot #=-
; ------------------------------------------------------------- ;
; calculate all points
Function mandelbrot(x1#, y1#, xstart#, ystart#, xzoom#, yzoom#)
; Local x, y, h, b, old, col
LockBuffer BackBuffer()
For x = 0 To x1#-1
For y = 0 To y1#-1
h# = DotsColor#(xstart# + xzoom# * x, ystart# + yzoom# * y) ; Color value
If h# <> old#
b# = 1.0 - h# * h# ; brightness
col = HSBtoRGB(h#, 0.8, b#)
old# = h#
EndIf
WritePixelFast x, y, col
Next
Next
UnlockBuffer BackBuffer()
End Function
; ------------------------------------------------------------- ;
; -=# DotsColor #=-
; ------------------------------------------------------------- ;
; Color value from 0.0 To 1.0 by iterations
Function DotsColor#(xval#, yval#)
; Local r, i, j, m
While (j# < maxiter#) And (m# < 4.0)
j#=j#+1.0
m# = r# * r# - i# * i#
i# = 2.0 * r# * i# + yval#
r# = m# + xval#
Wend
j# = j# / maxiter#
Return j#
End Function
; ------------------------------------------------------------- ;
; -=# RGB-Function - Come on, that's an important one... #=-
; ------------------------------------------------------------- ;
Function RGB(red, green, blue)
Return (red Shl 16) + (green Shl 8) + blue
End Function
; ------------------------------------------------------------- ;
; -=# HSB2RGB #=-
; ------------------------------------------------------------- ;
Function HSBtoRGB(hue#, saturation#, brightness#)
; Local red, green, blue, domainOffset // hue Mod 1/6
If brightness# = 0 Then Return 0
If saturation# = 0 Then Return RGB(Int(brightness#*255), Int(brightness#*255), Int(brightness#*255))
; Select not with <> allowed, have to use If here...
If hue# < 1.0/6.0
; red domain; green ascends
domainOffset# = hue#
red# = brightness#
blue# = brightness# * (1.0 - saturation#)
green# = blue# + (brightness# - blue#) * domainOffset# * 6
Else
If hue# < 2.0/6.0
; yellow domain; red descends
domainOffset# = hue# - 1.0/6.0
green# = brightness#
blue# = brightness# * (1.0 - saturation#)
red# = green# - (brightness# - blue#) * domainOffset# * 6.0
Else
If hue# < 3.0/6.0
; green domain; blue ascends
domainOffset# = hue# - 2.0/6.0
green# = brightness#
red# = brightness# * (1.0 - saturation#)
blue# = red# + (brightness# - red#) * domainOffset# * 6.0
Else
If hue# < 4.0/6.0
; cyan domain; green descends
domainOffset# = hue# - .5
blue# = brightness#
red# = brightness# * (1.0 - saturation#)
green# = blue# - (brightness# - red#) * domainOffset# * 6.0
Else
If hue# < 5.0/6.0
; blue domain; red ascends
domainOffset# = hue# - 5.0/6.0
blue# = brightness#
green# = brightness# * (1.0 - saturation#)
red# = green# + (brightness# - green#) * domainOffset# * 6.0
Else
; magenta domain; blue descends
domainOffset# = hue# - 5.0/6.0
red# = brightness#
green# = brightness# * (1.0 - saturation#)
blue# = red# - (brightness# - green#) * domainOffset# * 6.0
EndIf
EndIf
EndIf
EndIf
EndIf
Return RGB(red# * 255.0, green# * 255.0, blue# * 255.0)
End Function
Sveinung |
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| Try adding 'SetGraphicsDriver GLMax2DDriver()' before the Graphics command. The Gl driver catch the negative values for colors. The DX driver not. You can see a post of mark in the bug forum. http://www.blitzbasic.com/Community/posts.php?topic=48646 |
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| okay so I converted the b3d code over to B+ and it works. I converted the BMax code over to B+ and is still doesn't work. I wanted to see if there was an operator precendence problem. There isn't. One thing your missing is the j = j / maxval line in the DotDCol function is commented out but that just gets us a red screen instead of blue. Other than that the code looks the same. |
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| I know what it is! The DotCol function is returning an int it should return a float Function DotCol:Float(xval:Float,yval:Float) Local r:Float Local i:Float Local j:Float Local m:Float While (j < maxval) And (m < 4.0) j = j + 1.0 m = (r * r) - (i * i) i = ((2.0 * r) * i) + yval r = m + xval Wend j = j / maxval Return j EndFunction |
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| Scott your the MAN!!! Thanks Works fine now! Sveinung |
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| Works great! I want to see the picture in realtime rendering. |
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