Sprite trails

Dim nasty.Alien( 20 )

for l = 0 to 20
 nasty(l) = new Alien
 nasty(l)\x = rand(-10,10)
 nasty(l)\y = rand(-10,10)
next

;just move nasty 2 and 4
nasty(2)\x = nasty(2)\x + 1
nasty(4)\x = nasty(4)\x + 10

Function compareX(num,num1)
counter = 0
For a.alien = Each alien
   counter = counter + 1
   If counter = num then
      temp.alien = a.alien
   End If
   If counter = num1 then
      temp1.alien = a.alien
   End If
Next

Return temp\x - temp1\x

End Function

If compareX(2,4) = 0 then
   Print" Aliens are in the same X positions"
End If

Graphics 800,600

SetBuffer BackBuffer()


Type trail
	Field x,y
	Field size
	Field r,g,b
	Field time
	Field timer
End Type


Global trail_dis_time = 100 ; time trail stay on screen for

Global trail_R = 100; red
Global trail_G = 100; green
Global trail_B = 100; and blue of color of trail.

Global trail_timer = MilliSecs()
Global trail_time = 10 ; leave a trail every 10 milliseconds

While Not KeyHit(1)

	Cls


	If MilliSecs() > trail_timer + trial_time Then
		create_trail(MouseX(),MouseY(),1)
	End If
	

	update_trails()
	Flip
Wend
End


Function create_trail(x,y,size)

	t.trail = New trail
		t\x = x
		t\y = y
		t\size = size
		t\time = trail_dis_time
		t\timer = MilliSecs()
		t\r = trail_R
		t\g = trail_G
		t\b = trail_B
		
End Function


Function update_trails()

	For t.trail = Each trail
	
		Color t\r, t\g, t\b
	
		Rect t\x - (t\size/2), t\y - (t\size/2), t\size, t\size
		
		If MilliSecs() > t\time + t\timer Then
			Delete t.trail
		End If
		
	Next
	
End Function

Function paint(x,y,screen_image,r,g,b)

   LockBuffer ImageBuffer(screen_image)
   rgb= (a shl 24) or (r shl 16) or (g shl 8) or b; combine the ARGB into a number that writepixelfast can use
   WritePixelFast x,y,rgb,ImageBuffer(screen_image)
   UnlockBuffer ImageBuffer(screen_image)
End function

Graphics 800,600
SetBuffer BackBuffer()


Global image = CreateImage(800,600)



While Not KeyHit(1)

	Cls

	If MouseDown(1) Then
		paint(MouseX(),MouseY(),image,155,155,255); the the values for different colours :o)
	End If

	DrawImage image,0,0 ; draw the canvas so to speak, the drawing will go to
	Color 255,255,255
	Rect MouseX(),MouseY(),1,1
	Flip
Wend



Function paint(x,y,screen_image,r,g,b)

	LockBuffer ImageBuffer(screen_image) ; lock the imagebuffer for the screen image. MUST be locked!
	RGB= (a Shl 24) Or (r Shl 16) Or (g Shl 8) Or b; combine the ARGB into a number that writepixelfast can use
	WritePixelFast x,y,RGB,ImageBuffer(screen_image) ; write a pixel fast to the image buffer
	UnlockBuffer ImageBuffer(screen_image) ; unlock the buffer for the screen image. MUST be unlocked!

End Function

Graphics 800,600
SetBuffer BackBuffer()
HidePointer

Global image = CreateImage(800,600)



While Not KeyHit(1)
	Mouse_X = MouseX() ; record the mouse x position. For timing issues. The mousex() changes everytime it's called
	Mouse_Y = MouseY() ; record the mouse y position. Same reason as above.
	
	Cls
	
	If MouseDown(1) Then
		paint(mx,my,Mouse_X,Mouse_Y,image,155,155,255); the the values for different colours :o)
	End If

	mx = Mouse_X; record the last mouse X position
	my = Mouse_Y; record the last mouse Y position

	DrawImage image,0,0 ; draw the canvas so to speak, the drawing will go to
	Color 255,255,255
	Rect Mouse_X,Mouse_Y,1,1
	Flip

Wend



Function paint(mx,my,x,y,screen_image,r,g,b) ; point from the last mouse position, to the present

	Color r,g,b
	SetBuffer ImageBuffer(screen_image)
	Line x,y,mx,my ; draw a line from the last recorded mouse position, to the current one
	SetBuffer BackBuffer()

End Function