Code archives/Graphics/2D follow image/smooth waypoints

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2D follow image/smooth waypoints by Ross C2004
Modified from my 2d waypoint editor. You create waypoints by clicking. Press SPACE to start the image following the way points. Press Enter to stop. You can add waypoints at any time you wish.

Basically, if you say create an attack pattern for a spaceship in 2D, you don't want it to follow exactly. Instead you want it to curve round them. This is what this code does. Run and see for your self :)
; **** 2D waypoint editor, modified. Original Code by Ross C *****
; ****                 Modified code by Ross C               *****
; ****     create smooth transitions between way points      *****


Graphics 800,600
SetBuffer BackBuffer()

Global max_path_points=100

Dim pathx#(max_path_points-1); set up 101 path points
Dim pathy#(max_path_points-1); -1 because arrays start at zero

Global path_counter=-1
Global current_path=0
Global cx#=0
Global cy#=0
Global ex#=400
Global ey#=100
Global movement_started=0


While Not KeyHit(1)
	Cls
	
	If MouseHit(1) Then
			setpath(MouseX(),MouseY()); set path point with the mouses current coords
	End If
	
	If KeyHit(57) And movement_started=0 And path_counter>0 Then; if spacebar pressed then move rectangle
		current_path=0; reset the current path to 0
		cx=pathx(0); set the rectangles coords to the first path point
		cy=pathy(0)
		movement_started=1; set flag for movement started
		ex=400
		ey=100
	End If
	If KeyHit(28) Then; if the enter key is pressed then stop movement
		movement_started=0; clear flag for movement
		cx=pathx(0); set rectangle coords to the first path point
		cy=pathy(0)
		current_path=-1; set current path to none exsistant
	End If

	
	
	
	draw_path_points(); function for drawing the pathpoints
	If movement_started=1 Then move(); draw the moving rectangle and move it
	Color 200,200,200; set drawing color
	Rect MouseX()-1,MouseY()-1,2,2; draw mouse location with a rectangle
	Text 0,0,"Click mouse to set path point. Press spacebar to start animation. Press enter to stop."
	Text 0,10,"movement started="+movement_started
	Flip
Wend
End

Function move()
	ang#=0
	If current_path<path_counter Then; make sure the current path point is less than the highest
		ang=ATan2(pathy(current_path+1)-pathy(current_path),pathx(current_path+1)-pathx(current_path))
		;/\ basically means find the angle between the current path point and the next one /\
		cx=cx+Cos(ang)*3; increase the x coord of the rect following the path points based on the angle
		cy=cy+Sin(ang)*3; increase the y coord of the rect following the path points based on the angle
		Color 100,200,100; change drawing color
		Rect cx-3,cy-3,6,6; draw the rectangle central to it's coords
		If Abs(cx-pathx(current_path+1))<2 And Abs(cy-pathy(current_path+1))<2 Then
			; /\ if the rects coords are with a 1 pixel distance of the path point then /\
			current_path=current_path+1; increase the current path point number
			cx=pathx(current_path); set the rectangles coords to that of the next path point
			cy=pathy(current_path)
		End If
	End If
	angle=ATan2( cy - ey, cx - ex ); find the angl between the enemies and the waypoint follower
	dist=Sqr( (ex-cx)*(ex-cx)+(ey-cy)*(ey-cy) ); find the distance between them
	DebugLog dist
	ex=ex+(Cos(angle)/1)*(dist/30); move the enemy at speed relative to the distance
	ey=ey+(Sin(angle)/1)*(dist/30); move the enemy at speed relative to the distance
	Rect ex-15,ey-15,30,30; draw the enemy
End Function

Function setpath(x,y)
	path_counter=path_counter+1; increase counter
        If path_counter>max_path_points-1 Then; if counter is higher than the available number of path points then set it back
               path_counter=max_path_points-1
        Else; else 
	       pathx(path_counter)=x; record the x and y positions
	       pathy(path_counter)=y
        End If
End Function

Function draw_path_points()
	For loop=0 To path_counter; loop through all the path points
		Color 100,100,200
		Rect pathx(loop),pathy(loop),2,2
		If loop<path_counter Then; do this loop while the loop value is less than the highest path value
			Rect pathx(loop+1)-1,pathy(loop+1)-1,2,2; draw a rectangle at the path point so its central
			Color 50,50,150; change drawing color
			Line pathx(loop),pathy(loop),pathx(loop+1),pathy(loop+1); draw a line between the current point and the next one
		End If
	Next
End Function

Comments

Rck2005
A novel idea, at least to myself.


Pineapple2006
Thanks for this, just what I was looking for, though, I've shortened it a little, and used types instead of arrays:-



Dabz


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