Fading Intro

BlitzMax Forums/BlitzMax Programming/Fading Intro

gellyware

(Posted 2006) [#1]

Does anyone have any examples of how to fade an intro screen (displaying a white background with logo) into either a game screen or black?

degac

(Posted 2006) [#2]

uhh...I'm writing something for my incoming game...
try this one

'fx_image
Global list_imageFX:tlist=New tlist
Type timagefx
	Global event_raise:Int=0
	Field image
	Field v_alpha:Float,i_alpha#=-.01
	Field l_alpha:Float=1
	Field fademode=1
	Field x#,y#
	Field dx#,dy#
	Field rot#=0,i_rot#=0
	Field scale_x#=1
	Field scale_y#=1
	Field scale_dx#=0
	Field scale_dy#=0
	Field status=0
	Field action=0
	Field strip_number=10
	Field color[3]
	Field blendMode=ALPHABLEND
	Field checked:Int=0
	Field duration:Int
	'
	' control the audio (optional)
	Field channel:TChannel
	Field volume:Float
	Field volume_delta:Float
	

	

	
	Function Add:timageFx(_image:timage,action=0)
		Local t_imagefx:timagefx=New timageFX
		
		t_imageFX.image=_image
		t_imageFX.color[0]=255
		t_imageFX.color[1]=255
		t_imageFX.color[2]=255
		t_imageFX.v_alpha=1.0
		t_imageFX.l_alpha=0
		t_imageFX.action=action
		ListAddLast list_imageFX,t_imageFX
		
		Return t_imageFX
	End Function
	
	Method Strip(n=10)
	
	action=action|1
	strip_number=n
	
	End Method 

	Method Alpha(_alp#,i_alp#=0.1)
		v_alpha=_alp
		i_alpha=i_alp
	End Method
	
	Method SetFadeIn(timer=2000)
	v_alpha=0
	i_alpha=Float(100)/timer
	l_alpha=1
	fademode=0
		duration=timer
	'Print "Fade IN "+v_alpha+" INC: ("+i_alpha+")"
	End Method
	
	Method SetFadeOut(timer=2000)
	v_alpha=1
	i_alpha=-Float(100)/timer
	l_alpha=0
	fademode=1
	duration=timer
	'Print "Fade OUT "+v_alpha+" INC: ("+i_alpha+")"
	End Method
'	End Rem

	Method AudioFade(chan:TChannel,vol_s:Float)
	If duration=0 Return 
	channel=chan
	volume=vol_s
	volume_delta=Float(100)/duration

	End Method

	Method SetColor(r,g,b)
		color[0]=r
		color[1]=g
		color[2]=b
	End Method 
	
	Function ClearAll()
		For Local t:timageFX=EachIn list_imageFX
			ListRemove list_imageFX,t
			t.image=Null
			t=Null
		Next
	End Function
	
	Function Update()
	
	For Local t:timageFX=EachIn list_imageFX
		rit:Int=t.draw()
	Next
	Return rit
	End Function
	
	Method Draw()
		Select action
			Case 0' fade in & out
		
					If fademode=0
						v_alpha=v_alpha+i_alpha
						volume=volume+volume_delta
						If v_alpha>l_alpha status=1;Return 1
						
					Else
						v_alpha=v_alpha+i_alpha
						volume=volume-volume_delta
						If v_alpha<l_alpha status=1;Return 1
						
					End If
					
					
			Case 1
					If checked=0
						loop_s=0
						loop_f=GraphicsHeight()/strip_number
						LOOP_2=0
						loop_stp=loop_f
						checked=1
						
					End If
				
		
			
		End Select
		
		
		
		
		If volume<0 volume=0
		If volume>1 volume=1
		
		
		If channel<>Null
				SetChannelVolume channel,volume
				'		vol:-delta_vol
				ResumeChannel channel

		End If
		
		
		
		
		'draw image...
		
		o_blend=GetBlend()
		o_alpha#=GetAlpha()
		GetColor(O_r,O_g,O_b)
		GetScale(o_x#,o_y#)
		
		
		SetBlend BLENDmode
		SetScale 1,1
		SetAlpha v_alpha
		SetColor color[0],color[1],color[2]
			
				DrawImage image,x,y	
				
				Select action
					Case 1
						SetColor 0,0,0
						Repeat
							DrawRect 0,loop_s,GraphicsWidth(),loop_2
						loop_S:+loop_stp
						loop_2:+1
						
						Until loop_s>=loop_f
				End Select
				
				
		
		SetBlend o_blend
		SetScale o_X,o_Y
		SetAlpha o_alpha
		SetColor o_r,o_g,O_b
	End Method
	
	
End Type

and this one is the main prog

'test
Graphics 640,480
Include "fx_image.bmx"
Global image=LoadImage("gfx/bkg_04.png")
myfx:timagefx=timagefx.add(image)
myfx.SetFadeOut(10000)
	Repeat
		Cls
		ris=timagefx.update()
		Flip
	Until MouseHit(1) Or ris=1
myfx.SetFadeIn(10000)
	Repeat
		Cls
		ris=timagefx.update()
		Flip
	Until MouseHit(1) Or ris=1
End

of course you can change it if you want - and some things are not needed...you can just use the basic Bmax commands (see the type function Update/Draw)
Hope this helps
byez

ImaginaryHuman

(Posted 2006) [#3]

Draw your game screen. Then draw the title screen over the top of it, with a variable level of alpha blending in SetBlend AlphaBlend. Start with a solid title screen image and then vary the alpha to fade it out.

FlameDuck

(Posted 2006) [#4]

What AngelDaniel said.

gellyware

(Posted 2006) [#5]

Thanks for the input, degac your code got me thinking about some different things and here is the splash screen I came up with if anyone is interested.



Type TSplash
	Global list:TList= CreateList()
	
	Const alphaMax# = 1
	Const alphaMin# = 0
	Const fOUT = 0
	Const fIN = 1

	
	Field image:TImage 
	Field alpha#
	Field fade_duration
	Field hold_duration 
	
	Field milli
	Field mode    
	
	Function Create:TSplash(img:Object, width=800, Height=600)  
	
		'
		' CODE BELOW CREATES THE IMAGE THAT WILL BE FADED
		' CHANGE TO SUIT YOUR NEEDS 
		'                                                  
		
		Local image0:TImage = LoadImage(img)
		If not image0 Then RuntimeError("Unable to load splash logo!")   
		Local image1:TImage = CreateImage(width,Height,1,DYNAMICIMAGE|MASKEDIMAGE)
		                                       
		                                   
		MidHandleImage image0
		
		SetClsColor (255 , 255 , 255)
		Cls 
				
		DrawImage image0, width/2, Height/2
		GrabImage image1, 0, 0

		SetClsColor(0,0,0)
				
		Local splash:TSplash=New TSplash
			splash.image = image1
			splash.alpha = 1
			splash.fade_duration = 2000
			splash.hold_duration = 3000
			splash.milli = MilliSecs()
			splash.mode = splash.fOUT 
		ListAddLast list,splash
		
		Return splash
	End Function
	

	
	Method SetFadeIn(hd=2000, fd=2000)
		alpha = 0
		milli = MilliSecs()
		hold_duration = hd 
		fade_duration = fd 		
		mode = fIN	
	End Method
	
	Method SetFadeOut(hd=2000, fd=2000)
		alpha = 1
		milli = MilliSecs()
		hold_duration = hd 
		fade_duration = fd 	
		mode  = fOUT 
	End Method


	Function Update()
		Local stillGoing = False
		Local r
		
		For Local s:TSplash=EachIn list
			r = s.Draw()
			If not r Then stillGoing=True  
		Next  
		If not stillGoing       
			For Local s:TSplash=EachIn list
				s.image = Null 
				s.list.Remove s
			Next
		EndIf 
		
		Return stillGoing		
	End Function
	
	Method Draw()
		Local tt# , tl# 'total time, time left
		Local r# 		'result 
		  
		If mode = fOUT  
			If MilliSecs() > hold_duration + milli
				If MilliSecs() > fade_duration + hold_duration + milli Return 1 
				tt# = fade_duration + hold_duration + milli
				tl# = tt - MilliSecs()
				r# = Abs((tl / fade_duration) )		
				If r <= 0 Return 1             
				
				alpha = r			 	    
			EndIf
		EndIf 			
					
		If mode = fIN
				If MilliSecs() > fade_duration + hold_duration + milli Return 1 
				tt# = fade_duration + hold_duration + milli
				tl# = tt - MilliSecs()
				r# = Abs((tl / fade_duration) )   
				Print r
				If r <= 0 Return 1
				alpha = r				
		EndIf   
		
		Local prevBlend = GetBlend()
		
		SetAlpha(alpha)
		SetBlend(ALPHABLEND) 
		DrawImage image , 0 , 0 	
		SetBlend(prevBlend)	
		SetAlpha(1)
	EndMethod 
	
End Type


'
'test
'


Graphics 800,600
'fade out demo
'SetFadeOut(hold_duration, fade_duration)
'hold duration = length to hold graphic before fading OUT (in millisecs)
'fade duration = how long should the fade take to fade out (in millisecs)
Local splash:TSplash=TSplash.Create("image.png")
splash.SetFadeOut(2000 , 1000)

Local done = False 
While not done
	Cls
	If not TSplash.Update() done = True
	Flip 
Wend 

 
'fade in demo
'SetFadeIn(hold_duration, fade_duration)
'hold duration = length to hold graphic AFTER fading in (in millisecs)
'fade duration = how long should the fade take to fade in(in millisecs)
	                                                                     
	
splash:TSplash=TSplash.Create("image.png")
splash.SetFadeIn(2000 , 1000)

done = False 
While not done
	Cls
	If not TSplash.Update() done = True
	Flip 
Wend 

End

xlsior

(Posted 2006) [#6]

My old fade-to-black routine from the Code Archives:

http://www.blitzbasic.com/codearcs/codearcs.php?code=1281

(Also does a fade-to-white, and a smooth cross-fade from one image into another)

gellyware

(Posted 2006) [#7]

If I had only seen that yesterday... I'd be a couple hours richer!!!

:)