Knights!

Graphics 800,600

Global dude = CreateImage(20,20)
SetBuffer ImageBuffer(dude)
Color 255,0,0
Oval 0,0,20,20,1

Global dline = CreateImage(20,3)
SetBuffer ImageBuffer(dline)
Color 155,50,0
Rect 0,0,100,3,1

Global pltf = CreateImage(200,30)

SetBuffer ImageBuffer(pltf)
Color 155,250,0
Rect 0,0,200,30,1

Global pltfl = CreateImage(200,3)

SetBuffer ImageBuffer(pltfl)
Color 255,255,255
Rect 0,0,200,3,1


SetBuffer BackBuffer()
Global jumpheight# = 10

Global canjump = 0

Global jump = 0



Const gravity# = 0.4



	Type player



		Field x#

		Field y#

		Field h#

	
	End Type

	
	
	Type platform

	
		Field x

		Field y

		Field g

		
	End Type

	
	
createplatform()

	
createplayer()





While Not KeyHit ( 1 )



	Cls

		
			Text 50,50,"Jumpheight = " +Int(jumpheight)

			
			drawlines()		

			renderplatform()

			renderplayer()

			moveplayer()

			playerjump()

			collisionchecks()

	
	Flip

	
	
Wend





End



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Draw Lines			   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function drawlines()



	For p.player = Each player

	
		DrawImage dline,p\x + 3,p\y + 50

		
	Next

	
	For plat.platform = Each platform

	
		DrawImage pltfl,plat\x,plat\y - 1

	
	Next

	
	
End Function





;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Create Platform		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function createplatform()



	plat.platform = New platform

	
		plat\x = 400

		plat\y = 535

		
End Function





;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Create Player		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function createplayer()



	p.player = New player

	
	p\x = 300

	p\y = 540

	p\h = 10

	
End Function



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Render Player		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function renderplayer()



	For p.player = Each player

	
		DrawImage dude,p\x,p\y,0

		
	Next

	
End Function



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function :Render Platform		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function renderplatform()



	For plat.platform = Each platform

	
		DrawImage pltf,plat\x,plat\y

		
	Next

	
End Function





;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Move  Player 		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function moveplayer()



	If KeyDown ( 203 )

	
		For p.player = Each player

		
			p\x = p\x - 3

			
		Next

		
	ElseIf KeyDown  ( 205 )

	
		For p.player = Each player

		
			p\x = p\x + 3

			
		Next

		
	EndIf

	
	For p.player = Each player

	
		If p\y > 540 Then

		
			p\y = 540

			canjump = 0

			jump = 0

			jumpheight = 10

			
			
		EndIf

		
	Next

		
	
End Function



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Player Jump 			   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function playerjump()



	If KeyHit ( 57 ) And (jumpheight = 10 Or Int(jumpheight) = -1);(Int(jumpheight = -1)))

		
		canjump = 1

		jump = 1

		jumpheight = 10

				
	EndIf

	
	If  canjump = 1 And jump = 1 Then 

			
			If jumpheight <=0 Then

			
				For p.player = Each player

				
					For i = 0 To 1 + Abs(jumpheight)

						
						If collisionchecks() = True Then Exit

						
						p\y = p\y + 1

						
					Next

					
				Next

			
			Else

												
				For p.player = Each player

		
					For i = 0 To jumpheight

					
						If collisionchecks = True Then Exit

				
						p\y = p\y - 1

												
					Next

														
				Next

			
			EndIf

		
		
			
		jumpheight = jumpheight - gravity

		
		
			 
	Else

		
		jump = 0

		canjump = 0

		jumpheight = 10

		
	EndIf

		
		
End Function 



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;									   ;

;	Function : Collision checks		   ;

;									   ;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



Function collisionchecks()



	For p.player = Each player

		
		For plat.platform = Each platform	

		
			If ImagesCollide(dline,p\x + 3,p\y + 50,0,pltfl,plat\x,plat\y - 1,0) And jumpheight <0 Then

			
				canjump = 1

				jump = 0

				
				Return True

				
			ElseIf  p\y <540 And jumpheight = 10 Then

			
				canjump = 1

				jump = 1

				jumpheight = -1

				
				Return True

				
			EndIf

			
		Next

		
	Next

	
	
	
Return False



End Function

CREDIT to ORIGINAL POSTER
dunno who they were, but this snippet was posted in these forums a while back...

hope it helps...