Author Topic: Mandlebrot in a DX window (Read 2111 times)

GWS · « **on:** March 07, 2012, 07:39:22 PM »

Hi,

I've been playing and came up with this ..

It seems to give a different look to a mandlebrot - you can click on it to enlarge any point of interest.

' Mandlebrot - GWS March 2012
' using DirextX 2D
' Click on the fractal to enlarge the pattern at that point.
' Click Normal to return to the standard Mandlebrot display.

autodefine "OFF"

window w
int i,y,px,wstyle,run
int Width,Height
int mx,my,clickcount
float Z_re2,Z_im2,Z_re,Z_im,c_re,c_im
float x1,x2,y1,y2
float Rfac,Ifac,scale,Re,Im
pointer sprite1

Width=1024
Height=768
run = 1

wstyle = @minbox|@noautodraw
openwindow w,0,0,Width,Height,wstyle,0,"Mandlebrot",&handler
' create a DirectX screen (no allowance is made for the user not having DirectX - just go for it) ...
attachscreen(w,Width,Height,0)

frontpen backBuffer,RGB(255,255,255)
setfont backbuffer,"Arial",10,500
drawmode backBuffer,@TRANSPARENT

control backbuffer,@BUTTON,"Normal",Width*0.1,Height*0.85,70,25,0, 1
control backbuffer,@BUTTON,"Exit",Width*0.8,Height*0.85,70,25,0, 2

' working sprite to draw on - and to refresh from if the window needs re-painting ..
sprite1 = CREATESPRITE(Width,Height,1,1)

centerwindow w

scale = 1.0
clickcount = 0

' define the corners for two complex numbers (x1+iy1) and (x2+iy2) ..
x1 = -2
y1 = -1.2
x2 = 1
y2 = 1.2

' calculate factors to match screen pixels to corresponding complex values ..
Rfac = (x2 - x1)/(Width - 1)
Ifac = (y2 - y1)/(Height - 1)

fillscreen RGB(0,0,30)
flip

gosub NewPattern

drawsprite sprite1
move backBuffer,50,20
print backBuffer,"Click anywhere on the Fractal for an enlargement."

flip

waituntil run = 0 
freesprite sprite1
closescreen
closewindow w
end

sub handler(),int			:' just to keep the return(0) happy - yeuk!
select @MESSAGE
	case @IDCLOSEWINDOW
    run = 0
	case @idcontrol
		select @controlid
			case 1
' set to display normal mandlebrot ..
				clickcount = 0
				Scale = 1.0
				x1 = -2
				x2 = 1
				y1 = -1.2
				y2 = 1.2
				setfocus w
	
				gosub Redraw
	
				return
			case 2
				run = 0
		endselect
	case @IDLBUTTONDN
' where was the mouse button clicked ..
		mx = @MOUSEX
		my = @MOUSEY
		clickcount = clickcount + 1

' magnify by 10 at each click ..
		Scale = clickcount * 10

' calculate the Real and Imaginary values corresponding to the point clicked ..
		Re = x1 + @mousex * Rfac
		Im = y2 - @mousey * Ifac

' plot from the selected Re +/- 1.5 , and from Im -/+ 1.2
		x1 = Re - 1.5 / Scale
		x2 = Re + 1.5 / Scale
		y1 = Im - 1.2 / Scale
		y2 = Im + 1.2 / Scale

' recalculate the Re and Im factors for the current scale ..
		gosub Redraw
	
	case @IDPAINT
			drawspritexy sprite1,0,0
			flip
endselect
return(0)					:' shouldn't be needed in a civilized system
endsub


sub NewPattern
float xm
int NIter
' routine to generate a Mandlebrot pattern ..
' increase the number of iterations as the scale increases 
NIter = 50 * sqrt(Scale) 

SpriteToBuffer(sprite1)
Fillscreen RGB(0,0,50), SpriteBuffer
LOCKBUFFER SpriteBuffer

for y = 0 to Height - 1
	c_im = y2 - y * Ifac

	for px = 0 to Width - 1
		c_re = x1 + px * Rfac
		Z_re = c_re
		Z_im = c_im

		for i = 1 to NIter
			xm = i											:' colour multiplier

			Z_re2 = Z_re * Z_re
			Z_im2 = Z_im * Z_im

			if (Z_re2 + Z_im2 > 4)
				WritePixelFast px,y,rgb(30+xm,90+xm,190+xm),SpriteBuffer
				goto breaknext
			endif

			Z_im = 2 * Z_re * Z_im + c_im
			Z_re = Z_re2 - Z_im2 + c_re

		next i

label breaknext

	next px
next y

UNLOCKBUFFER SpriteBuffer
endsub


sub Redraw
' redraw the pattern after a change ..
Rfac = (x2 - x1)/(Width - 1)
Ifac = (y2 - y1)/(Height - 1)

gosub NewPattern

drawsprite sprite1

move backBuffer,50,20
print backBuffer,"Click on the Fractal to enlarge a section."

flip
endsub

best wishes,

Graham

[Modified to compile under the strict rules of IWB2 ..

]

LarryMc · « **Reply #1 on:** March 07, 2012, 09:13:24 PM »

As always, pretty neat, Graham.

However it won't complie in the latest version of IWB.

You have a GOTO BREAK statement with the corresponding label.

BREAK is now a keyword that is used to break out of loops other than FOR/NEXT

Also the compiler generates a warning if the handler routine is not formally structured
i.e. : SUB handler(),int
and the handler has to return 0 or their will be warning messages.

Note: it you modified it to zoom in on a continuos loop it looks like you're flying by a solar flare or something.

LarryMc

GWS · « **Reply #2 on:** March 08, 2012, 12:30:55 AM »

Ah! .. that's what comes of late night projects ..

I'd forgotten all the new-fangled constraints, and some of the code is several years old.

I do hate that return 0 stuff from subs that don't need to return anything.

I'll try to make it compliant ..

It only zooms where you click .. it's not auto-zoom - although that's an idea ..

The mandlebrot is the big black ugly thing in the centre - all the pretty stuff is round the edges.

best wishes,

Graham

GWS · « **Reply #3 on:** March 08, 2012, 01:57:06 AM »

OK .. I've modified the code above to comply with the strict rules of play ..

Can't say I'm keen on the SUB handler(),int, or the Return(0) idea.
The original user guide said .. You don't need a 'Return' statement if the subroutine has nothing to return.
And if it returns nothing, why specify a return type?

It's getting a bit too 'C' ish I reckon .. $:-\$

Still on with the fun - I've got another idea ..

best wishes,

Graham

LarryMc · « **Reply #4 on:** March 08, 2012, 10:58:03 AM »

Quote from: GWS on March 08, 2012, 01:57:06 AM

Can't say I'm keen on the SUB handler(),int, or the Return(0) idea.
The original user guide said .. You don't need a 'Return' statement if the subroutine has nothing to return.
And if it returns nothing, why specify a return type?

That statement is still true.
But a message handler has always returned a value; it's just that the compiler had special case code so you didn't have to enter it.
Sapero had to add some code to insure that the user didn't try to pass parameters to OnMenu, OnControl,OnMessage functions and the special case code was getting in his way. So he standardized the way subroutines work, including handlers.

Except for the BREAK statement in your original code the other stuff simply generates warnings, not errors.
There are even compiler options now that you can opt for that keep those particular warnings from appearing if you so desire.

And I'm waiting for your next idea...

LarryMc

GWS · « **Reply #5 on:** March 08, 2012, 07:54:55 PM »

'OnMenu, OnControl, OnMessage functions' ..

I didn't even know they existed ..

The 'pro' version has always been a logical maze for me.

I obviously need to have a read through the latest user guide.

Next idea is stuck temporarily .. I'll get back to it momentarily ..

Graham

GWS · « **Reply #6 on:** March 13, 2012, 11:09:05 PM »

I've played with it a bit more, and I think this version is probably the best ..

It uses pre-defined colours, but some components are randomised ..

Code: [Select]

' Mandlebrot - GWS March 2012
' using DirextX 2D
' second version using pre-set colours
' Click on the fractal to enlarge the pattern at that point.
' Click Normal to return to the standard Mandlebrot display.

autodefine "OFF"

window w
int i,y,px,wstyle,run
int Width,Height
int mx,my,clickcount
float Z_re2,Z_im2,Z_re,Z_im,c_re,c_im
float x1,x2,y1,y2
float Rfac,Ifac,scale,Re,Im
pointer sprite1

int col[255]

for i = 0 to 63
	col[0+i] = rgb(rnd(3*i),3*i,3*i+128)
	col[64+i] = rgb(i+150,2*i,rnd(2*i)+128)
	col[128+i] = rgb(3*i+150,rnd(255-3*i),170)
	col[192+i] = rgb(rnd(250),50,255-2*i)
next i

Width=1024
Height=768
run = 1

wstyle = @minbox|@noautodraw
openwindow w,0,0,Width,Height,wstyle,0,"Mandlebrot",&handler
' create a DirectX screen (no allowance is made for the user not having DirectX - just go for it) ...
attachscreen(w,Width,Height,0)

frontpen backBuffer,RGB(255,255,255)
setfont backbuffer,"Arial",10,500
drawmode backBuffer,@TRANSPARENT

control backbuffer,@BUTTON,"Normal",Width*0.1,Height*0.85,70,25,0, 1
control backbuffer,@BUTTON,"Exit",Width*0.8,Height*0.85,70,25,0, 2

' working sprite to draw on - and to refresh from if the window needs re-painting ..
sprite1 = CREATESPRITE(Width,Height,1,1)

centerwindow w

scale = 1.0
clickcount = 0

' define the corners for two complex numbers (x1+iy1) and (x2+iy2) ..
x1 = -2
y1 = -1.2
x2 = 1
y2 = 1.2

' calculate factors to match screen pixels to corresponding complex values ..
Rfac = (x2 - x1)/(Width - 1)
Ifac = (y2 - y1)/(Height - 1)

fillscreen RGB(0,0,30)
flip

gosub NewPattern

drawsprite sprite1
move backBuffer,50,20
print backBuffer,"Click anywhere on the Fractal for an enlargement."

flip

waituntil run = 0 
freesprite sprite1
closescreen
closewindow w
end

sub handler(),int			
select @MESSAGE
	case @IDCLOSEWINDOW
    run = 0
	case @idcontrol
		select @controlid
			case 1
' set to display normal mandlebrot ..
				clickcount = 0
				Scale = 1.0
				x1 = -2
				x2 = 1
				y1 = -1.2
				y2 = 1.2
				setfocus w
	
				gosub Redraw
	
				case 2
				run = 0
		endselect
	case @IDLBUTTONDN
' where was the mouse button clicked ..
		mx = @MOUSEX
		my = @MOUSEY
		clickcount = clickcount + 1

' magnify by 10 at each click ..
		Scale = clickcount * 10

' calculate the Real and Imaginary values corresponding to the point clicked ..
		Re = x1 + @mousex * Rfac
		Im = y2 - @mousey * Ifac

' plot from the selected Re +/- 1.5 , and from Im -/+ 1.2
		x1 = Re - 1.5 / Scale
		x2 = Re + 1.5 / Scale
		y1 = Im - 1.2 / Scale
		y2 = Im + 1.2 / Scale

' recalculate the Re and Im factors for the current scale ..
		gosub Redraw
	
	case @IDPAINT
			drawspritexy sprite1,0,0
			flip
endselect
return(0)					
endsub


sub NewPattern
int NIter,clr,xm
' routine to generate a Mandlebrot pattern ..

NIter = 150 

SpriteToBuffer(sprite1)
Fillscreen RGB(0,0,20), SpriteBuffer
LOCKBUFFER SpriteBuffer

for y = 0 to Height - 1
	c_im = y2 - y * Ifac

	for px = 0 to Width - 1
		c_re = x1 + px * Rfac
		Z_re = c_re
		Z_im = c_im

		for i = 1 to NIter
			xm = i											:' colour multiplier

			Z_re2 = Z_re * Z_re
			Z_im2 = Z_im * Z_im

			if (Z_re2 + Z_im2 > 4) 

				if xm = NIter
					clr = 0
				else
					clr = col[xm]
				endif

				WritePixelFast px,y,clr,SpriteBuffer
				goto breaknext

			endif

			Z_im = 2 * Z_re * Z_im + c_im
			Z_re = Z_re2 - Z_im2 + c_re

		next i

label breaknext

	next px
next y

UNLOCKBUFFER SpriteBuffer
endsub


sub Redraw
' redraw the pattern after a change ..
Rfac = (x2 - x1)/(Width - 1)
Ifac = (y2 - y1)/(Height - 1)

gosub NewPattern

drawsprite sprite1

move backBuffer,50,20
print backBuffer,"Click on the Fractal to enlarge a section."

flip
endsub

There are lots of variables to tweak to get different colour effects.

Also, increasing the number of iterations gives a sharper image, at the expense of taking longer to produce.

best wishes,

Graham

IonicWind Software

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