Julia set fractal generator optimisation (drawpoint)

This topic contains 8 replies, has 5 voices, and was last updated by taumel 2 years, 8 months ago.

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July 16, 2016 at 9:42 pm #2203

abakobo

Participant

I made a little Julia set fractal generator.

My main issue is that drawpoint is actualy very slow for real time plot by plot generation. Using a separate canvas then render to image is a bit more slow and it looks like using pixmap is a bad idea for that kind of thing (have not tried).
Can I draw points to the screen faster? (I remember when writing the same on a 486 with C. Drawing points directly to the VRAM was way faster than calculating them!)
In mx2, writing the color index to an array is reasonably fast, but then drawing it to the screen takes more or less then same time than calculating Julia’s iterations!

[crayon-5cba16a9c225b369345343 inline="true" ]
'
'
' Julia Set example by abakobo
'
'     a monkey 2 example-learning exercise
'     next steps/points of interest is to optimise: -the drawpoint speed
'                                                   -the choice for globals, fields, locals
'
'             Of course the use of the imagearray should finally be skipped for better perfomances
'

#Import "<std>"
#Import "<mojo>"

Using std..
Using mojo..

Global w_width:=800 'window size
Global w_height:=600

Global MaxIt:=32 'Julia's calculation precision
Global Threshold:=2 'Julia's escape Threshold
Global zoom:=2.7 'inverted zoom factor

Global Palette:Color[] 'indexed colors array

Class Julia Extends Window
	
  Field imageArray:= New int[w_width,w_height] 'array to store image as indexed colors (to check process times)

	Method New(title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )

    'Silly call to Super.new (don't understand why I can't do it directly from main, maybe something wrong with Enum)
    Super.New( title,width,height,WindowFlags.Center )
  
  End
	
	Method OnRender( canvas:Canvas ) Override
	
		App.RequestRender()
		
		'
		'  local vars declaration
		'
		Local Cr:Float, Ci:Float, Zr:Float, Zi:Float ' the complex number parts (should probably use struct...)
		Local ta:Int,tb:Int,tj:Int 'the timer vars
    Local x:Int,y:Int 'coord iterators
    
    
    '
    ' get the mouse coord and transform it to the complex constant used in Julia set
    '
		Cr=1+(App.MouseLocation.x-w_width)/(w_width/2.0)
		Ci=1+(App.MouseLocation.y-w_height)/(w_height/2.0)
		
    '
    ' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)
    ' and copy it to the imagearray array
    '
		ta=Millisecs()
    For x=0 Until w_width
      For y=0 Until w_height
        Zr=(x-(w_width/2.0))*(zoom/w_width)
        Zi=(y-(w_height/2.0))*(zoom/w_height)
        imageArray[x,y]=NbIter(Zr,Zi,MaxIt,Threshold,Cr,Ci)
      Next	
    Next
    tb=Millisecs()
    tj=tb-ta 'Records the time it took to calculate Julia and copy it to the array
    
    '
    ' Draw the colors to the canvas using the precalculated palette (indexed-->rgb)
    '
    ta=Millisecs()
    For x=0 Until w_width
     	For y=0 Until w_height
       	canvas.Color=Palette[imageArray[x,y]]
       	canvas.DrawPoint( x,y )
      Next	
    Next
    tb=Millisecs()
    tb=tb-ta 'records the time it took to draw indexed array to canvas
    
    '
    ' Prints timers and FPS
    '
    canvas.Color=Palette[MaxIt-1]
    canvas.DrawText("Move mouse arroud to see various Julia sets",0,0)
    canvas.DrawText("Julia to array time: "+tj,0,15)
    canvas.DrawText("array to canvas time: "+tb,0,30)
    canvas.DrawText("FPS:"+App.FPS,0,45)
  End

End

'
' squared complex+const series (Julia)
'
Function NbIter:Int(Zr:Float,Zi:Float,max_iter:Int,exit_radius:Float,Cr:Float,Ci:Float)

  Local i:=0
  Local Zr2:Float, Zi2:Float, er2:Float
  er2=exit_radius*exit_radius
  Zr2=Zr*Zr
  Zi2=Zi*Zi
  While i<max_iter-1 And Zr2+Zi2<er2
    Zi=2*Zr*Zi + Ci
    Zr=Zr2-Zi2 +Cr
    Zr2=Zr*Zr
    Zi2=Zi*Zi
    i+=1
  End
  Return i
End

'
' Create the indexed color Palette
'
Function CreateGlobalPalette:Void()
  Palette=New Color[MaxIt] 'Palette is Global, declared at top
	For Local i:=0 Until MaxIt-1
		Palette[i]=New Color(Abs(Sin(2.0*Pi*i/MaxIt)),Abs(Sin(1.2*Pi*i/MaxIt)),0.6-(i/(MaxIt*1.0))*0.3)
	Next
	Palette[MaxIt-1]=New Color(0,0,0)
End

Function Main()
	CreateGlobalPalette()
	New AppInstance
	New Julia ("Julia",w_width,w_height)
	App.Run()
End

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[crayon-5cba16a9c225b369345343 inline="true" ]

' Julia Set example by abakobo

' a monkey 2 example-learning exercise

' next steps/points of interest is to optimise: -the drawpoint speed

' -the choice for globals, fields, locals

' Of course the use of the imagearray should finally be skipped for better perfomances

#Import "<std>"

#Import "<mojo>"

Using std..

Using mojo..

Global w_width:=800 'window size

Global w_height:=600

Global MaxIt:=32 'Julia's calculation precision

Global Threshold:=2 'Julia's escape Threshold

Global zoom:=2.7 'inverted zoom factor

Global Palette:Color[] 'indexed colors array

Class Julia Extends Window

Field imageArray:= New int[w_width,w_height] 'array to store image as indexed colors (to check process times)

Method New(title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )

'Silly call to Super.new (don't understand why I can't do it directly from main, maybe something wrong with Enum)

Super.New( title,width,height,WindowFlags.Center )

End

Method OnRender( canvas:Canvas ) Override

App.RequestRender()

' local vars declaration

Local Cr:Float, Ci:Float, Zr:Float, Zi:Float ' the complex number parts (should probably use struct...)

Local ta:Int,tb:Int,tj:Int 'the timer vars

Local x:Int,y:Int 'coord iterators

' get the mouse coord and transform it to the complex constant used in Julia set

Cr=1+(App.MouseLocation.x-w_width)/(w_width/2.0)

Ci=1+(App.MouseLocation.y-w_height)/(w_height/2.0)

' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)

' and copy it to the imagearray array

ta=Millisecs()

For x=0 Until w_width

For y=0 Until w_height

Zr=(x-(w_width/2.0))*(zoom/w_width)

Zi=(y-(w_height/2.0))*(zoom/w_height)

imageArray[x,y]=NbIter(Zr,Zi,MaxIt,Threshold,Cr,Ci)

tb=Millisecs()

tj=tb-ta 'Records the time it took to calculate Julia and copy it to the array

' Draw the colors to the canvas using the precalculated palette (indexed-->rgb)

ta=Millisecs()

For x=0 Until w_width

For y=0 Until w_height

canvas.Color=Palette[imageArray[x,y]]

canvas.DrawPoint( x,y )

tb=Millisecs()

tb=tb-ta 'records the time it took to draw indexed array to canvas

' Prints timers and FPS

canvas.Color=Palette[MaxIt-1]

canvas.DrawText("Move mouse arroud to see various Julia sets",0,0)

canvas.DrawText("Julia to array time: "+tj,0,15)

canvas.DrawText("array to canvas time: "+tb,0,30)

canvas.DrawText("FPS:"+App.FPS,0,45)

End

' squared complex+const series (Julia)

Function NbIter:Int(Zr:Float,Zi:Float,max_iter:Int,exit_radius:Float,Cr:Float,Ci:Float)

Local i:=0

Local Zr2:Float, Zi2:Float, er2:Float

er2=exit_radius*exit_radius

Zr2=Zr*Zr

Zi2=Zi*Zi

While i<max_iter-1 And Zr2+Zi2<er2

Zi=2*Zr*Zi + Ci

Zr=Zr2-Zi2 +Cr

Zr2=Zr*Zr

Zi2=Zi*Zi

i+=1

End

Return i

End

' Create the indexed color Palette

Function CreateGlobalPalette:Void()

Palette=New Color[MaxIt] 'Palette is Global, declared at top

For Local i:=0 Until MaxIt-1

Palette[i]=New Color(Abs(Sin(2.0*Pi*i/MaxIt)),Abs(Sin(1.2*Pi*i/MaxIt)),0.6-(i/(MaxIt*1.0))*0.3)

Palette[MaxIt-1]=New Color(0,0,0)

End

Function Main()

CreateGlobalPalette()

New AppInstance

New Julia ("Julia",w_width,w_height)

App.Run()

End

[/crayon]

Edit: .monkey2 files are blocked for upload for security reasons…

July 17, 2016 at 12:56 am #2214

Mark Sibly

Keymaster

Had a quick go at speeding this via render-to-pixmap and it’s not bad – was going 22FPS-ish, now does 60 if the mouse is at the edges!

A bit of hackery involved – it draws directly to a pixel ‘ptr’ instead of SetPixel( x,y ) so it’s not recalculating pixel address all the time.

 
'
'
' Julia Set example by abakobo
'
'     a monkey 2 example-learning exercise
'     next steps/points of interest is to optimise: -the drawpoint speed
'                                                   -the choice for globals, fields, locals
'
'             Of course the use of the imagearray should finally be skipped for better perfomances
'
 
#Import "<std>"
#Import "<mojo>"
 
Using std..
Using mojo..
 
Global w_width:=800 'window size
Global w_height:=600
 
Global MaxIt:=32 'Julia's calculation precision
Global Threshold:=2 'Julia's escape Threshold
Global zoom:=2.7 'inverted zoom factor
 
Global Palette:UInt[]

Class Julia Extends Window

	Field pixmap:=New Pixmap( w_width,w_height )
	Field image:=New Image( w_width,w_height,TextureFlags.Dynamic )

	Method New( title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )
		Super.New( title,width,height,WindowFlags.Center )
	End
	
	Method OnRender( canvas:Canvas ) Override
	
		App.RequestRender()
		
		'
		'  local vars declaration
		'
		Local Cr:Float, Ci:Float, Zr:Float, Zi:Float ' the complex number parts (should probably use struct...)
		Local ta:Int,tb:Int,tj:Int 'the timer vars
		Local x:Int,y:Int 'coord iterators
    
    
    '
    ' get the mouse coord and transform it to the complex constant used in Julia set
    '
		Cr=1+(App.MouseLocation.x-w_width)/(w_width/2.0)
		Ci=1+(App.MouseLocation.y-w_height)/(w_height/2.0)
		
    '
    ' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)
    ' and copy it to the imagearray array
    '
		ta=Millisecs()
		
		For y=0 Until w_height

			Local p:=Cast<UInt Ptr>( pixmap.PixelPtr( 0,y ) )
		
			Zi=(y-(w_height/2.0))*(zoom/w_height)
				
			For x=0 Until w_width
			
				Zr=(x-(w_width/2.0))*(zoom/w_width)
				
				Local t:=NbIter( Zr,Zi,MaxIt,Threshold,Cr,Ci )
				
				p[x]=Palette[t]
				
			Next
			
		Next
		
		tb=Millisecs()
		tj=tb-ta 'Records the time it took to calculate Julia and copy it to the array
    
		image.Texture.PastePixmap( pixmap,0,0 )
		canvas.DrawImage( image,0,0 )
    
		' Prints timers and FPS
		'
		canvas.Color=Color.Black
    
		canvas.DrawText("Move mouse arroud to see various Julia sets",0,0)
		canvas.DrawText("Julia to array time: "+tj,0,15)
		canvas.DrawText("array to canvas time: "+tb,0,30)
		canvas.DrawText("FPS:"+App.FPS,0,45)
	End
 
End
 
'
' squared complex+const series (Julia)
'
Function NbIter:Int(Zr:Float,Zi:Float,max_iter:Int,exit_radius:Float,Cr:Float,Ci:Float)
 
	Local i:=0
	Local Zr2:Float, Zi2:Float, er2:Float
	er2=exit_radius*exit_radius
	Zr2=Zr*Zr
	Zi2=Zi*Zi
	While i<max_iter-1 And Zr2+Zi2<er2
		Zi=2*Zr*Zi + Ci
		Zr=Zr2-Zi2 +Cr
		Zr2=Zr*Zr
		Zi2=Zi*Zi
		i+=1
	Wend
	Return i
End
 
Function ColorToBGRA:UInt( color:Color )
	Return UInt(color.a*255) Shl 24 | UInt(color.b*255) Shl 16 | UInt(color.g*255) Shl 8 | UInt(color.r*255)
End
'
' Create the indexed color Palette
'
Function CreateGlobalPalette:Void()

	Palette=New UInt[MaxIt] 'Palette is Global, declared at top
  
	For Local i:=0 Until MaxIt-1
		Palette[i]=ColorToBGRA( New Color(Abs(Sin(2.0*Pi*i/MaxIt)),Abs(Sin(1.2*Pi*i/MaxIt)),0.6-(i/(MaxIt*1.0))*0.3) )
	Next

	Palette[MaxIt-1]=ColorToBGRA( Color.Black )

End
 
Function Main()
	CreateGlobalPalette()
	New AppInstance
	New Julia( "Julia",w_width,w_height )
	App.Run()
End

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' Julia Set example by abakobo

' a monkey 2 example-learning exercise

' next steps/points of interest is to optimise: -the drawpoint speed

' -the choice for globals, fields, locals

' Of course the use of the imagearray should finally be skipped for better perfomances

#Import "<std>"

#Import "<mojo>"

Using std..

Using mojo..

Global w_width:=800 'window size

Global w_height:=600

Global MaxIt:=32 'Julia's calculation precision

Global Threshold:=2 'Julia's escape Threshold

Global zoom:=2.7 'inverted zoom factor

Global Palette:UInt[]

Class Julia Extends Window

Field pixmap:=New Pixmap( w_width,w_height )

Field image:=New Image( w_width,w_height,TextureFlags.Dynamic )

Method New( title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )

Super.New( title,width,height,WindowFlags.Center )

End

Method OnRender( canvas:Canvas ) Override

App.RequestRender()

' local vars declaration

Local Cr:Float, Ci:Float, Zr:Float, Zi:Float ' the complex number parts (should probably use struct...)

Local ta:Int,tb:Int,tj:Int 'the timer vars

Local x:Int,y:Int 'coord iterators

' get the mouse coord and transform it to the complex constant used in Julia set

Cr=1+(App.MouseLocation.x-w_width)/(w_width/2.0)

Ci=1+(App.MouseLocation.y-w_height)/(w_height/2.0)

' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)

' and copy it to the imagearray array

ta=Millisecs()

For y=0 Until w_height

Local p:=Cast<UInt Ptr>( pixmap.PixelPtr( 0,y ) )

Zi=(y-(w_height/2.0))*(zoom/w_height)

For x=0 Until w_width

Zr=(x-(w_width/2.0))*(zoom/w_width)

Local t:=NbIter( Zr,Zi,MaxIt,Threshold,Cr,Ci )

p[x]=Palette[t]

tb=Millisecs()

tj=tb-ta 'Records the time it took to calculate Julia and copy it to the array

image.Texture.PastePixmap( pixmap,0,0 )

canvas.DrawImage( image,0,0 )

' Prints timers and FPS

canvas.Color=Color.Black

canvas.DrawText("Move mouse arroud to see various Julia sets",0,0)

canvas.DrawText("Julia to array time: "+tj,0,15)

canvas.DrawText("array to canvas time: "+tb,0,30)

canvas.DrawText("FPS:"+App.FPS,0,45)

End

' squared complex+const series (Julia)

Function NbIter:Int(Zr:Float,Zi:Float,max_iter:Int,exit_radius:Float,Cr:Float,Ci:Float)

Local i:=0

Local Zr2:Float, Zi2:Float, er2:Float

er2=exit_radius*exit_radius

Zr2=Zr*Zr

Zi2=Zi*Zi

While i<max_iter-1 And Zr2+Zi2<er2

Zi=2*Zr*Zi + Ci

Zr=Zr2-Zi2 +Cr

Zr2=Zr*Zr

Zi2=Zi*Zi

i+=1

Wend

Return i

End

Function ColorToBGRA:UInt( color:Color )

Return UInt(color.a*255) Shl 24 | UInt(color.b*255) Shl 16 | UInt(color.g*255) Shl 8 | UInt(color.r*255)

End

' Create the indexed color Palette

Function CreateGlobalPalette:Void()

Palette=New UInt[MaxIt] 'Palette is Global, declared at top

For Local i:=0 Until MaxIt-1

Palette[i]=ColorToBGRA( New Color(Abs(Sin(2.0*Pi*i/MaxIt)),Abs(Sin(1.2*Pi*i/MaxIt)),0.6-(i/(MaxIt*1.0))*0.3) )

Palette[MaxIt-1]=ColorToBGRA( Color.Black )

End

Function Main()

CreateGlobalPalette()

New AppInstance

New Julia( "Julia",w_width,w_height )

App.Run()

End

July 17, 2016 at 3:56 pm #2228

abakobo

Participant

wow! now running at 30fps with FullHD on the edges!

Thanks for that. It shows how pointers are powerfull and is a great lesson.
I will need some time to understand all of that well. Especially the Cast operator that let you use p as an array. Is that some kind of pointer arithmetics?

I will have to try some simple examples to get that part.

July 17, 2016 at 8:59 pm #2236

Simon Armstrong

Participant

I was interested to see if there was any difference between float and double. I replaced all “Float” with “F” and tried both Alias F:Float and Alias F:Double but could not discern any difference. I suppose under the hood this only affects storage times not calculation times.

July 17, 2016 at 9:27 pm #2237

Mark Sibly

Keymaster

> Especially the Cast operator that let you use p as an array. Is that some kind of pointer arithmetics?

Since pixels can be stored in a number of different formats, PixelPtr just returns a general purpose ‘UByte Ptr’ and leaves it up to you to cast it to the correct type (if you need to).

Our pixels are UInts, so the cast converts this to a ‘UInt Ptr’. It’s still just a pointer though, and it will have have the same value. It’s just that when you do math with it (eg: index it with the [] operator, or add/subtract to/from it) the fact the pointer is a ‘UInt Ptr’ will be taken into account. For example, p+=1 where p is a ‘UInt Ptr’ will actually add 4 to p, because UInts are 4 bytes long.

July 22, 2016 at 5:13 pm #2345

abakobo

Participant

I continued a bit on this exercise and had the flowing conclusions:

-as Simon said Float or Double doesn’t change anything (due to 64bit CPU?)

-Struct is making things slower (made a complex struct based on Vec2)
One thing about that is that setting a Field directly is (much) faster than setting via Properties.
So why would we use such properties if it is only to get and set the field the same way it would be done directly?

I made a github repo for my further exercices and posted the two julia versions on it…
https://github.com/abakobo/learn_monkey2

July 23, 2016 at 5:18 am #2358

Danilo

Participant

So why would we use such properties if it is only to get and set the field the same way it would be done directly?

If you just want to set a field, without the need to get
the class/object noticed about the change, you can just
use fields directly.
But, such fields are always read+write, so for a read-only field
you need to use a property.

You would do a field like ‘Window.Title’ (String) as Property,
because just setting the string is often not enough.
The property calls an OS/API function like SetWindowTitle()
in the background if you change win.Title – so that’s where
you want to use Properties.
Or setting win.X really moves a window on desktop, because of
property-internal OS-calls. Just setting an Int value would not
magically move the window.

For structs that just hold plain/simple public data (like Matrix),
you could just use plain fields, most of the time.

July 26, 2016 at 4:39 pm #2467

abakobo

Participant

Here’s the most optimized I could find, if anyone see something to be done for optimization welcome!
I tried a bit to use RGB24 for the pixmap but don’t understand how to get a pointer of that length. But I suppose it won’t change anything with speed or may be worse.
It can zoom and move and save the picture now. Can we set the png quality for pixmap saving? It does not have the exact same look when saved.

[crayon-5cba16a9d768b701939845 inline="true" ]'
'
' Julia Set example - resizable window
'
'     a monkey 2 example-learning exercise
'     points of interest is to optimise:               -the drawpoint speed
'                                                        (done?, optimised by marksibly, using pixmap and pointer,
'                                                        pointer is faster local compared to field,
'                                                        should try using smaller pixel formats for pixmap (not done, need to understand how to point to 24bits))
'                                                     -the choice for globals, fields, locals, struct:
'                                                        using struct for iterations is slower, see julia_with_struct(non_optim).monkey2 (github)
'                                                        Double or Float doesn't change anything (on 64bit computers at least?)
'                                                        Local is faster for basic variables, fields and globals seems to have same speed
'
'                                                     -??? 
'
'                                            
 
#Import "<std>"
#Import "<mojo>"
 
Using std..
Using mojo..
 
Global w_width:=1000 'initial window size
Global w_height:=700
 
Global MaxIt:=16 'Julia's calculation precision
Global Threshold:Double=2.5 'Julia's escape Threshold
Global pxSize:Double=0.006 'Initial size of a pixel on the complex plane (inverted zoom factor)
Global viewCenter_r:Double=0.0, viewCenter_i:Double=0.0 'Initial center point for viewing (on complex plane)
Global move_spd:Double=0.06
Global Palette:UInt[]
 
Class Julia Extends Window
 
	
	Field image:=New Image( w_width,w_height,TextureFlags.Dynamic )
	Field Cr:Double=0.0, Ci:Double=0.0
  Field modif_const:=True 'Blocks the anim or not (true=animated) (bad name)
  Field count:=-1 'count for the auto anim
  Field modif_const_mouse:=False 'flag/selector for auto or mouse anim (bad name)
  Field pixmap:=New Pixmap( w_width,w_height,PixelFormat.RGBA32 )
  Field saveIt:=False
  
 
	Method New( title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )
		Super.New( title,width,height,flags )
	End
	
	'
	'These are equivalent to Keyboard.KeyPressed(Key.XXX) But with better memory of things
	'Sometimes in OnRender with low FPS it skips some Keyboard.Keyxxxxx here not!
	'
	Method OnKeyEvent( event:KeyEvent ) Override	
		Select event.Type
			Case EventType.KeyDown
			Select event.Key
				Case Key.Space
			    modif_const=Not modif_const
			  Case Key.P
          saveIt=True
        Case Key.C
          modif_const_mouse=Not modif_const_mouse
			End Select
		End Select		
	End Method

	Method OnRender( canvas:Canvas ) Override
	
	
	'
	'  local vars declaration
	'
	Local Zr:Double, Zi:Double ' the complex number parts (should probably use struct...)
	Local ta:Int,tb:Int,tj:Int 'the timer vars
	Local x:Int,y:Int 'coord iterators
	Local max_wh:Int 'to get the maximal value of the window height or width
  Local p:UInt Ptr
		
	' mandatory for continuous render
	App.RequestRender()
		
    '
    ' adapt to window size (resizable window)
    '
    If  w_width<>Self.Rect.Size.X or w_height<>Self.Rect.Size.Y
    
      Local maxs:=Max(w_width,w_height)
    	w_width=Self.Rect.Size.X
    	w_height=Self.Rect.Size.Y
    	Local maxs2:=Max(w_width,w_height)
    	
    	pxSize=pxSize*(maxs/(maxs2*1.0)) 'adapt zoom to new window size (because zoom factor is pixel's lenght)
    	
    	image.Discard() 'Images are not Garbage Collected so it's always better to Discard before changing it... (here it's a Field so probably not usefull)
    	image=New Image( w_width,w_height,TextureFlags.Dynamic )
    	pixmap=New Pixmap( w_width,w_height )
    End If
    
    
    
    '
    '
    '   Keyboard controls
    '
    '
    If Keyboard.KeyDown(Key.Up) Then viewCenter_i-=move_spd*(pxSize/0.006)
    If Keyboard.KeyDown(Key.Down) Then viewCenter_i+=move_spd*(pxSize/0.006)
    If Keyboard.KeyDown(Key.Left) Then viewCenter_r-=move_spd*(pxSize/0.006)
    If Keyboard.KeyDown(Key.Right) Then viewCenter_r+=move_spd*(pxSize/0.006)
    If Keyboard.KeyDown(Key.W|Key.Raw) Then pxSize=pxSize/1.05
    If Keyboard.KeyDown(Key.S|Key.Raw) Then pxSize=pxSize*1.05
    If Keyboard.KeyDown(Key.A|Key.Raw) Then Threshold/=1.01
    If Keyboard.KeyDown(Key.D|Key.Raw) Then Threshold*=1.01
    If Keyboard.KeyDown(Key.I|Key.Raw)
      MaxIt+=1
      CreateGlobalPalette()
    Endif
    If Keyboard.KeyDown(Key.K|Key.Raw) 
      MaxIt=Max(2,MaxIt-1)
      CreateGlobalPalette()
    Endif
   
    
    '
    ' auto or mouse anim
    '
    If modif_const_mouse=True
     '
     ' get the mouse coord and transform it to the complex constant used in Julia set
     '
     If modif_const=True
      Cr=(App.MouseLocation.x-(w_width/2.0))*pxSize+viewCenter_r
      Ci=(App.MouseLocation.y-(w_height/2.0))*pxSize+viewCenter_i
		 Endif
		Else
		 '
		 ' create an anim while modifying the julia's const
		 '
		 If modif_const=True
		  count+=1
		  Cr=1.65*Cos(count/29.0)
      Ci=1.4*Sin(count/30.0)
     Endif
    Endif
		
		
    '
    ' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)
    ' and copy it to the pixmap with pointer for faster copy (faster than stepixel because the adress only calculated #height times)
    '
		
		For y=0 Until w_height
 
			p=Cast<UInt Ptr>( pixmap.PixelPtr( 0,y ) )
		
			Zi=(y-(w_height/2.0))*pxSize+viewCenter_i
				
			For x=0 Until w_width
			
				Zr=(x-(w_width/2.0))*pxSize+viewCenter_r
				
				Local t:=NbIter( Zr,Zi,MaxIt,Threshold,Cr,Ci )
				
				p[x]=Palette[t]
				
			Next
			
		Next
		
    '
    '  copy the pixmap to an image and put the image to the main canvas
    '
		image.Texture.PastePixmap( pixmap,0,0 )
		canvas.DrawImage( image,0,0 )

    '
    ' Save the pixmap (if asked) before drawing text on it
    '
    If saveIt=True 'this is on the eventlistener for better response while on low FPS
      saveIt=False
      Local filename:="Nothing"
      filename = RequestFile("Save the file","png",True,"Julia")
      print ("youy"+filename+"youy")
      If filename<>""
        pixmap.Save(filename)
      Else
        Notify("Blempro","No files where selected")
      Endif
    
    Endif
    
		' Prints
		'
		canvas.Color=Color.White
    
		canvas.DrawText("Space: Pause/Play --- C to switch to auto-anim or mouse-anim --- P:Save as PNG",0,0)
		canvas.DrawText("W/S(Raw):Zoom --- A/D(Raw):Thershold --- I/K:Iterations --- Cursor:Move",0,20)
		canvas.DrawText("Cr:"+Cr,0,40)
    canvas.DrawText(" Ci:"+Ci,175,40)
    canvas.DrawText(" Iter:"+MaxIt,350,40)
		canvas.DrawText("FPS:"+App.FPS,0,55)
	End
 
End
 
'
' squared complex+const series (Julia)
'
Function NbIter:Int(Zr:Double,Zi:Double,max_iter:Int,exit_radius:Double,Cr:Double,Ci:Double)
 
	Local i:=0
	Local Zr2:Double, Zi2:Double, er2:Double
	er2=exit_radius*exit_radius
	Zr2=Zr*Zr
	Zi2=Zi*Zi
	While i<max_iter-1 And Zr2+Zi2<er2
		Zi=2*Zr*Zi + Ci
		Zr=Zr2-Zi2 +Cr
		Zr2=Zr*Zr
		Zi2=Zi*Zi
		i+=1
	Wend
	Return i
End
 
Function ColorToBGRA:UInt( color:Color )
	Return UInt(color.a*255) Shl 24 | UInt(color.b*255) Shl 16 | UInt(color.g*255) Shl 8 | UInt(color.r*255)
End
'
' Create the indexed color Palette
'
Function CreateGlobalPalette:Void()
 
	Palette=New UInt[MaxIt] 'Palette is Global, Max It is global. declared at top
  
	For Local i:=0 Until MaxIt-1
		Palette[i]=ColorToBGRA( New Color(0.9*Abs(Sin(1.0*Pi*i/MaxIt)),0.9*Abs(Sin(1.0*Pi*i/MaxIt)),0.35-(i/(MaxIt*1.0))*0.34) )
	Next
 
	Palette[MaxIt-1]=ColorToBGRA( Color.Black )
 
End
 
Function Main()
	CreateGlobalPalette()
	New AppInstance
	New Julia( "Julia",w_width,w_height )
	App.Run()
End

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[crayon-5cba16a9d768b701939845 inline="true" ]'

' Julia Set example - resizable window

' a monkey 2 example-learning exercise

' points of interest is to optimise: -the drawpoint speed

' (done?, optimised by marksibly, using pixmap and pointer,

' pointer is faster local compared to field,

' should try using smaller pixel formats for pixmap (not done, need to understand how to point to 24bits))

' -the choice for globals, fields, locals, struct:

' using struct for iterations is slower, see julia_with_struct(non_optim).monkey2 (github)

' Double or Float doesn't change anything (on 64bit computers at least?)

' Local is faster for basic variables, fields and globals seems to have same speed

' -???

#Import "<std>"

#Import "<mojo>"

Using std..

Using mojo..

Global w_width:=1000 'initial window size

Global w_height:=700

Global MaxIt:=16 'Julia's calculation precision

Global Threshold:Double=2.5 'Julia's escape Threshold

Global pxSize:Double=0.006 'Initial size of a pixel on the complex plane (inverted zoom factor)

Global viewCenter_r:Double=0.0, viewCenter_i:Double=0.0 'Initial center point for viewing (on complex plane)

Global move_spd:Double=0.06

Global Palette:UInt[]

Class Julia Extends Window

Field image:=New Image( w_width,w_height,TextureFlags.Dynamic )

Field Cr:Double=0.0, Ci:Double=0.0

Field modif_const:=True 'Blocks the anim or not (true=animated) (bad name)

Field count:=-1 'count for the auto anim

Field modif_const_mouse:=False 'flag/selector for auto or mouse anim (bad name)

Field pixmap:=New Pixmap( w_width,w_height,PixelFormat.RGBA32 )

Field saveIt:=False

Method New( title:String,width:Int,height:Int,flags:WindowFlags=WindowFlags.Resizable )

Super.New( title,width,height,flags )

End

'These are equivalent to Keyboard.KeyPressed(Key.XXX) But with better memory of things

'Sometimes in OnRender with low FPS it skips some Keyboard.Keyxxxxx here not!

Method OnKeyEvent( event:KeyEvent ) Override

Select event.Type

Case EventType.KeyDown

Select event.Key

Case Key.Space

modif_const=Not modif_const

Case Key.P

saveIt=True

Case Key.C

modif_const_mouse=Not modif_const_mouse

End Select

End Method

Method OnRender( canvas:Canvas ) Override

' local vars declaration

Local Zr:Double, Zi:Double ' the complex number parts (should probably use struct...)

Local ta:Int,tb:Int,tj:Int 'the timer vars

Local x:Int,y:Int 'coord iterators

Local max_wh:Int 'to get the maximal value of the window height or width

Local p:UInt Ptr

' mandatory for continuous render

App.RequestRender()

' adapt to window size (resizable window)

If w_width<>Self.Rect.Size.X or w_height<>Self.Rect.Size.Y

Local maxs:=Max(w_width,w_height)

w_width=Self.Rect.Size.X

w_height=Self.Rect.Size.Y

Local maxs2:=Max(w_width,w_height)

pxSize=pxSize*(maxs/(maxs2*1.0)) 'adapt zoom to new window size (because zoom factor is pixel's lenght)

image.Discard() 'Images are not Garbage Collected so it's always better to Discard before changing it... (here it's a Field so probably not usefull)

image=New Image( w_width,w_height,TextureFlags.Dynamic )

pixmap=New Pixmap( w_width,w_height )

End If

' Keyboard controls

If Keyboard.KeyDown(Key.Up) Then viewCenter_i-=move_spd*(pxSize/0.006)

If Keyboard.KeyDown(Key.Down) Then viewCenter_i+=move_spd*(pxSize/0.006)

If Keyboard.KeyDown(Key.Left) Then viewCenter_r-=move_spd*(pxSize/0.006)

If Keyboard.KeyDown(Key.Right) Then viewCenter_r+=move_spd*(pxSize/0.006)

If Keyboard.KeyDown(Key.W|Key.Raw) Then pxSize=pxSize/1.05

If Keyboard.KeyDown(Key.S|Key.Raw) Then pxSize=pxSize*1.05

If Keyboard.KeyDown(Key.A|Key.Raw) Then Threshold/=1.01

If Keyboard.KeyDown(Key.D|Key.Raw) Then Threshold*=1.01

If Keyboard.KeyDown(Key.I|Key.Raw)

MaxIt+=1

CreateGlobalPalette()

Endif

If Keyboard.KeyDown(Key.K|Key.Raw)

MaxIt=Max(2,MaxIt-1)

CreateGlobalPalette()

Endif

' auto or mouse anim

If modif_const_mouse=True

' get the mouse coord and transform it to the complex constant used in Julia set

If modif_const=True

Cr=(App.MouseLocation.x-(w_width/2.0))*pxSize+viewCenter_r

Ci=(App.MouseLocation.y-(w_height/2.0))*pxSize+viewCenter_i

Endif

Else

' create an anim while modifying the julia's const

If modif_const=True

count+=1

Cr=1.65*Cos(count/29.0)

Ci=1.4*Sin(count/30.0)

Endif

' Calculates Julia in indexed colors (iterations up to MaxIt-1 due to array starting at 0)

' and copy it to the pixmap with pointer for faster copy (faster than stepixel because the adress only calculated #height times)

For y=0 Until w_height

p=Cast<UInt Ptr>( pixmap.PixelPtr( 0,y ) )

Zi=(y-(w_height/2.0))*pxSize+viewCenter_i

For x=0 Until w_width

Zr=(x-(w_width/2.0))*pxSize+viewCenter_r

Local t:=NbIter( Zr,Zi,MaxIt,Threshold,Cr,Ci )

p[x]=Palette[t]

' copy the pixmap to an image and put the image to the main canvas

image.Texture.PastePixmap( pixmap,0,0 )

canvas.DrawImage( image,0,0 )

' Save the pixmap (if asked) before drawing text on it

If saveIt=True 'this is on the eventlistener for better response while on low FPS

saveIt=False

Local filename:="Nothing"

filename = RequestFile("Save the file","png",True,"Julia")

print ("youy"+filename+"youy")

If filename<>""

pixmap.Save(filename)

Else

Notify("Blempro","No files where selected")

Endif

' Prints

canvas.Color=Color.White

canvas.DrawText("Space: Pause/Play --- C to switch to auto-anim or mouse-anim --- P:Save as PNG",0,0)

canvas.DrawText("W/S(Raw):Zoom --- A/D(Raw):Thershold --- I/K:Iterations --- Cursor:Move",0,20)

canvas.DrawText("Cr:"+Cr,0,40)

canvas.DrawText(" Ci:"+Ci,175,40)

canvas.DrawText(" Iter:"+MaxIt,350,40)

canvas.DrawText("FPS:"+App.FPS,0,55)

End

' squared complex+const series (Julia)

Function NbIter:Int(Zr:Double,Zi:Double,max_iter:Int,exit_radius:Double,Cr:Double,Ci:Double)

Local i:=0

Local Zr2:Double, Zi2:Double, er2:Double

er2=exit_radius*exit_radius

Zr2=Zr*Zr

Zi2=Zi*Zi

While i<max_iter-1 And Zr2+Zi2<er2

Zi=2*Zr*Zi + Ci

Zr=Zr2-Zi2 +Cr

Zr2=Zr*Zr

Zi2=Zi*Zi

i+=1

Wend

Return i

End

Function ColorToBGRA:UInt( color:Color )

Return UInt(color.a*255) Shl 24 | UInt(color.b*255) Shl 16 | UInt(color.g*255) Shl 8 | UInt(color.r*255)

End

' Create the indexed color Palette

Function CreateGlobalPalette:Void()

Palette=New UInt[MaxIt] 'Palette is Global, Max It is global. declared at top

For Local i:=0 Until MaxIt-1

Palette[i]=ColorToBGRA( New Color(0.9*Abs(Sin(1.0*Pi*i/MaxIt)),0.9*Abs(Sin(1.0*Pi*i/MaxIt)),0.35-(i/(MaxIt*1.0))*0.34) )

Palette[MaxIt-1]=ColorToBGRA( Color.Black )

End

Function Main()

CreateGlobalPalette()

New AppInstance

New Julia( "Julia",w_width,w_height )

App.Run()

End

[/crayon]

July 27, 2016 at 2:23 pm #2483

taumel

Spectator

When i was into Julia, i followed this route: a) find a fast formula, b) optimise the code, c) take advantage of symmetry, d) utalise multithreading, e) go with a pixel shader.

And i always liked them with colour cycling. :O)

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Julia set fractal generator optimisation (drawpoint)

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