[bb] 2D follow image/smooth waypoints by Ross C [ 1+ years ago ]

[BlitzBot]

Title : 2D follow image/smooth waypoints
Author : Ross C
Posted : 1+ years ago

Description : 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

Code :

Code (blitzbasic) Select Expand

; **** 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 :


Rck(Posted 1+ years ago)

 A novel idea, at least to myself.


Pineapple(Posted 1+ years ago)

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

Code Select Expand

Graphics 800,600
SetBuffer BackBuffer()

Type moveObject
Field x,y
Field px,py
End Type


While Not KeyHit(1)
Cls

If MouseHit(1) Then
setpath(MouseX(),MouseY(),400,100)
End If

move()
Color 200,200,200
Rect MouseX()-1,MouseY()-1,2,2
Rect 400,100,2,2
Flip
Wend
End


Function move()
For loopObjects.moveObject = Each moveObject
ang#=0
ang=ATan2(loopObjectspy-loopObjectsy,loopObjectspx-loopObjectsx)
loopObjectsx=loopObjectsx+Cos(ang)*3
loopObjectsy=loopObjectsy+Sin(ang)*3
Color 100,200,100
Rect loopObjectsx-3,loopObjectsy-3,6,6
If Abs(loopObjectsx-loopObjectspx)<2 And Abs(loopObjectsy-loopObjectspy)<2 Then
Delete loopObjects
End If
Next
End Function


Function setPath(x,y,futureX,futureY)
createPath.moveObject = New moveObject
createPathx = x
createPathy = y
createPathpx = futureX
createPathpy = futureY
End Function

Dabz [/i]