PATH EDITOR
BlitzPlus Forums/BlitzPlus Programming/PATH EDITOR
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Hi guys, i was wondering if anyone could tell me how to write a path editor function, one that would allow you to click where you want the path points. If someone could maybe show me some very basic code, (just to allow the user to click points and have something following the path) i would be very grateful. Thank for any help BLUE :) |
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This is what i have tried so far but somethings wrong, i can't quite think what it might be :(.start Global new_id=1 ; stores a new id Global current_id=1 ; holds the current target id Type path Field x Field y Field id End Type Function create_point() ; create a path point p.path = New path p\x=Int(MouseX()) ; store x position p\y=Int(MouseY()) ; store y position p\id=new_id new_id=new_id+1 End Function Function update_path(x,y) ; use objects co-ordinates to calculate the path For p.path = Each path ; cycle through each point If p\id=current_id ; until id matches current id If x<p\x Then x=x+1 If x>p\x Then x=x-1 If y<p\y Then y=y+1 If y>p\y Then y=y-1 If x=p\x And y=p\y Then current_id=current_id+1 EndIf Plot p\x,p\y Next End Function |
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Hey again. Here's some code i put together that should do what you want. :DGraphics 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 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 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); increase the x coord of the rect following the path points based on the angle cy=cy+Sin(ang); 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))<1 And Abs(cy-pathy(current_path+1))<1 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 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 |
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Updated it. wasn't using a float for the angle so it would sometimes run straight off the pathpoints :o) |
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Thankyou so much joker, i am ever so grateful for your response and kind help. Thank god theres people like you around :) Thanks again joker BLUE :) |
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anytime :) |
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Oh, ;-), just one more thing joker, could explain to me exactly what this line please? (just to help me in my understanding of why it works): If Abs(cx-pathx(current_path+1))<1 And Abs(cy-pathy(current_path+1))<1 Then If you could just explain to me what each part does and why. Thanks joker BLUE :) |
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If Abs(cx-pathx(current_path+1))<1 Abs means make the number positive regardless. cx is the current x coord of the rectangle. pathx(0) is the array that holds the x locations of the path points. current_path+1 is the current waypoint the rectangle is on. The plus one means the bit of code will compare the rectangles x coord with the x coords of the next waypoint. So, let cx=100 and let current_path=5 and let pathx(5)=103 if Abs(cx-pathx(current_path))<1 if abs(cx-pathx(5))<1 if abs(100-103)<1 if abs(3)<1 If the distance is less than one pixel then, current_path is incremented. And Abs(cy-pathy(current_path+1))<1 same as before, except compare the y coord of the rectangle with the y coord of the next path point. If you need anymore help, plz post back :) |
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Thanks every so much joker, i'm your biggest fan right now ;) lol. Seriously though, i really really appriciate all your kind wisdom to get me through this :) I'm gonna go and experiment with this command now. Thanks again m8 BLUE :) |
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Again, no problem :D |
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Ok (cough) i'm sorry to bother you again joker but i was just wondering if you could check this code and help me out here. Basically, i have tried to modify the code in order for me to get a better understanding of it, but for some reason it doesn't seem to be working and i can't see why :( Heres the code: Global pathx#=0 ;these are used to position the object on the path Global pathy#=0 Global id_counter=-1 ; keeps track of current point created Global current_point=0 ; current point to follow Global max_points=100 ; maximum allowed number of points Dim point_x(max_points-1) Dim point_y(max_points-1) ;****************************************** ;MAIN CODE ;****************************************** move=0 While Not KeyHit(1) Cls If MouseHit(1) Then create_point(MouseX(),MouseY()); set path point with the mouses current coords End If If KeyHit(57) And move=0 And id_counter>0 Then; if spacebar pressed then move rectangle current_point=0; reset the current path to 0 pathx=point_x(0); set the rectangles coords to the first path point pathy=point_y(0) move=1; set flag for movement started End If If KeyHit(28) Then; if the enter key is pressed then stop movement move=0; clear flag for movement pathx=point_x(0); set rectangle coords to the first path point pathy=point_y(0) current_point=-1; set current path to none exsistant End If follow_path(); function for drawing the pathpoints If move=1 Then update_path(); 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 create_point(x,y) id_counter=id_counter+1 If id_counter>max_points-1 id_counter=max_points-1 Else point_x(id_counter)=x ; assign give values to x and y fields point_y(id_counter)=y EndIf End Function Function update_path() angle#=0 If current_point<id_counter angle=ATan2(point_y(current_point+1)-point_y(current_point),point_x(curent_point+1)-point_x(current_point)) pathx=pathx+Cos(angle) pathy=pathy+Sin(angle) Rect pathx-3,pathy-3,6,6 If Abs(pathx-point_x(current_point+1))<1 And Abs(pathy-point_y(current_point+1))<1 Then current_point=current_point+1; increase the current path point number pathx=point_x(current_point); set the rectangles coords to that of the next path point pathy=point_y(current_point) End If EndIf End Function Function follow_path() For a=0 To id_counter Rect point_x(a),point_y(a),2,2 If a<id_counter Rect point_x(a+1)-1,point_y(a+1)-1,2,2 Line point_x(a),point_y(a),point_x(a+1),point_y(a+1) EndIf Next End Function Thanks for your kind help joker :) BLUE |
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hehe, perfect coding except from you spelt current wrong :) In function update_path angle=ATan2(point_y(current_point+1)-point_y(current_point),point_x(curent_point+1)-point_x(current_point)) one of the currents is spelled curent :D Function update_path() angle#=0 If current_point<id_counter ;*************************************** angle=ATan2(point_y(current_point+1)-point_y(current_point),point_x(curent_point+1)-point_x(current_point)); <<<**** current spelt wrong :) ;*************************************** pathx=pathx+Cos(angle) pathy=pathy+Sin(angle) Rect pathx-3,pathy-3,6,6 If Abs(pathx-point_x(current_point+1))<1 And Abs(pathy-point_y(current_point+1))<1 Then current_point=current_point+1; increase the current path point number pathx=point_x(current_point); set the rectangles coords to that of the next path point pathy=point_y(current_point) End If EndIf End Function It's wee mistakes like that, that sometimes throw me off to :) |
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:0 OOPS!!!! lol, my bad. I wouldn't have ever found that problem,lol I really hate it when that happens :) I could have sworn that the code was right hehe :) Ah well. Thanks ever so much joker for you help You are the most patient person i have ever had the honour of recieving help from. Thanks again :) BLUE |
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:0 FINALLY, IT WORKS!!!!!!!! :) :) :) Thankyou very much joker for your patience and kind wisdom, i can finally sleep well tonight. :) BLUE |
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:D |