; PROJECT : Echo or Motion Effect
; AUTHOR  : Kev Picone - http://PlayBasic.com
; CREATED : 14/11/2021
; EDITED  : 14/11/2021
; ---------------------------------------------------------------------



	// -------------------------------------------------------
	// ---------------------- MAIN LOOP ----------------------
	// -------------------------------------------------------



	type tobject
		X#(10)
		Y#(10)
		
		SpeedX#
		SpeedY#
		Colour
	endtype	

	Dim Objects(35) as tobject

	for lp=1 to getarrayelements(Objects())
			Objects(lp)= new tobject
			x#=rnd(800)
			y#=rnd(600)
			
			
			for poslp=0 to 10
				Objects(lp).x#(poslp) = x#
				Objects(lp).y#(poslp)= y#
			next
			
			Speed#=rndrange#(10,20)
			Angle#=Rnd(360)
			Objects(lp).speedx#=cos(Angle#)*Speed#
			Objects(lp).speedy#=sin(Angle#)*Speed#
			Objects(lp).Colour =rndrgb()
	next




	Screen=Newfximage(GetScreenWidth(),GetScreenheight())
	

	// -------------------------------------------------------
	do	// -------------------- MAIN LOOP ---------------------
	// -------------------------------------------------------



				for lp=1 to getarrayelements(Objects())
					x#=Objects(lp).x#(0)
					y#=Objects(lp).y#(0)

					x#+=Objects(lp).speedx#
					y#+=Objects(lp).speedy#

					//  scroll old positions down
					for oldpos=10 to 1 step -1
						Objects(lp).x#(oldpos)=Objects(lp).x#(oldpos-1)						
						Objects(lp).y#(oldpos)=Objects(lp).y#(oldpos-1)						
					next	

					if x#<0 		then x#=0 	: Objects(lp).speedx#*= -1
					if x#>800 	then x#=800 : Objects(lp).speedx#*= -1
					if y#<0 		then y#=0 	: Objects(lp).speedy#*= -1
					if y#>600 	then y#=600 : Objects(lp).speedy#*= -1

					Objects(lp).x#(0)=x#
					Objects(lp).y#(0)=y#
					
				next

		
		
		rendertoimage Screen
		cls 0
				// render 
				lockbuffer			
				; set ink pen drawing mode to Alpha Addition / Alpha ADD	
				inkmode 1+64
				
				; step through the objects and the draw the oldest ones first
				; looping to the last down to first.
				for pass=10 to 0 step -1	
					blendlevel#=cliprange#(pass/10.0,0,1)
										
					BlendColour =255-(255*BlendLevel#)
					BlendColour=Rgb(BlendColour,BlendColour,BlendColour)


					//  Draw all the objects from this pass in one group
					for lp=1 to getarrayelements(Objects())
						x#=Objects(lp).x#(pass)
						y#=Objects(lp).y#(pass)

						//  Compute the objects colour with the fade level
						ThisRGB = rgbAlphamult (Objects(lp).Colour, BlendColour)
						
						// draw it as a circle
						circlec x#,y#,32,true,ThisRGB
					next
				next
			
				unlockbuffer				
	
				; set inkmode back to normal
				inkmode 1	
				rendertoscreen
				drawimage screen,0,0,false
				
	
		sync
		wait 10		
	loop spacekey()