Shatter Screen Wipe?

 ;
; Falling Tiles
; -------------
;
; (c) Richard Lawrence <richard@...;
; Version 1.1 (5th Jan 2001).
; Thanks to Mikkel Loekke for the "GetImage" function.
;
; This simple function takes whatever is on the backbuffer, breaks it
; up into a number of tiles and then proceeds to make them fall off
; the screen.
;
; Instructions: Run the program, hit any key (bar ESC) to make the
; picture explode. After its exploded, hit any key to quit.
;
; NOTE: If you're not running Blitz v1.35 then you'll need to convert
; the jpg file to bmp and modify the LoadBuffer command in the code!
;
; Licence: Feel free to use this in your own code. Some credit would be
; nice but its not essential.
;
; ----------------------------------------------------------------------


; These are the number of sqaures across and down the image should be
; broken up into. The higher the slower it is but the better it looks.
; Using 80 for ACROSS and 60 for DOWN is very nice but jitters slightly.
; Don't try 640 and 480 - it locked my laptop up!

Const ACROSS = 20  ; Its best if this value is divisible by 640
Const DOWN = 15    ; Its best if this value is divisible by 480

; Create a type square. This contains the location of the tile, its
; velocity and the image it will be showing.

Type square
	Field x,y        ; location
	Field xvel,yvel  ; velocity of movement
	Field image      ; tile image
End Type
Dim grid.square(ACROSS, DOWN)

; Set graphics mode and load image into the frontbuffer
Graphics 640,480
; NOTE! If you're not running v1.35 of Blitz then you'll need to
; covert the picture into a bmp file and edit this line!
LoadBuffer(FrontBuffer(), "BlitzLogo.bmp")

; Display the picture
WaitKey

; Make the picture fall
fall_picture()

; Wait for them to press a key
SetBuffer FrontBuffer()
Text 20,20, "Press a key to finish ..."
WaitKey

; Finish
End

; fall_picture()
; Break the screen into tiles and then make them fall off the screen

Function fall_picture()	
	; Set the buffer to that of the picture
	SetBuffer FrontBuffer()

	; Work out the size of each square
	xsize = 640/ACROSS
	ysize = 480/DOWN	
		
	; Loop through each square, first across then down
	For i = 0 To ACROSS-1
		For j = 0 To DOWN-1
			; Create a new instance
			grid(i,j) = New square
			; Grab the image at the location on the screen
			grid(i,j)\image = GetImage (i*xsize, j*ysize, (i+1)*xsize, (j+1)*ysize)
			; Store its location on the screen
			grid(i,j)\x = i*xsize;
			grid(i,j)\y = j*ysize;
			; Work out how fast and which direction the tile will drift
			; from -3 (fast left) to +3 (fast right)
			grid(i,j)\xvel = Rnd(6) - 3;
			; Work out its velocity, negative values mean that it will
			; move upwards before going down again
			grid(i,j)\yvel = -Rnd(9)
		Next
	Next

	; Set the buffer to the back one	
	SetBuffer BackBuffer()

	; Loop through drawing each tile. If its off the screen, don't
	; draw it but increase the vanished counter. When the counter
	; hits ACROSS x DOWN then all tiles have gone off the screen.
	While vanished <> (ACROSS * DOWN)
		Cls
		vanished = 0
		
		For i = 0 To ACROSS-1
			For j = 0 To DOWN-1
				; Check tile is on the screen
				If grid(i,j)\y < 640 Then
					; Increase the y's velocity by one. This simulates
					; gravity meaning that the tile will speed up
					; going downwards
					grid(i,j)\yvel = grid(i,j)\yvel + 1
					; Update the x and y co-ordinates by adding the
					; velocity values. Note xvel is not changed, the
					; tiles do not change speed from left to right
					grid(i,j)\y = grid(i,j)\y + grid(i,j)\yvel
					grid(i,j)\x = grid(i,j)\x + grid(i,j)\xvel
					; Draw it
					DrawImage grid(i,j)\image, grid(i,j)\x, grid(i,j)\y
				Else
					; Update the vanished counter
					vanished = vanished + 1
				End If
			Next 
		Next 
		Flip
	Wend
	
	; Free all memory up (image first then the type)
				
	For i = 0 To ACROSS-1
		For j = 0 To DOWN-1
			FreeImage grid(i,j)\image
			Delete grid(i,j)
		Next
	Next
End Function

; Grab an image from a set of co-ordinates.
; Provided by Mikkel Loekke.

Function GetImage(LIx1, LIy1, LIx2, LIy2)
	; Work out width and height of the section we want
	LIw=LIx2-LIx1
	LIh=LIy2-LIy1
	; Create a blank image of that width and height
	LItempimg = CreateImage(LIw,LIh)
	; Grab into this, the picture at those co-ordinates. Excessive
	; picture will be clipped
	GrabImage(LItempimg,LIx1,LIy1)
	; Return it
	Return LItempimg
End Function

Include "explosions.bb"

AppTitle "Hit SPACE..."

Graphics 640, 480, 0, 2
SetBuffer BackBuffer ()

InitExplosions ()

image = LoadImage ("blah.bmp") ; Screen-sized image...

bang.RenderedExplosion = RenderExplosion (image, 16, 16)

Repeat

	Cls

	; Note: EXPLODE_Num is a global variable containing the number of explosion particles on-screen...

	If EXPLODE_Num = 0
		DrawImage image, 0, 0
	EndIf
	
	If KeyHit (57)
		StartRenderedExplosion (bang, 0, 0, 0, 0, 0.025)
	EndIf
	
	UpdateExplosions ()
	
	Flip
	
Until KeyHit (1)

; Do this when you no longer need the pre-rendered explosion...

FreeRenderedExplosion (bang)

End