directial movement

Dreglor · Post by **Dreglor** » Thu Dec 18, 2003 2:42 am

how do you convert a angle (0-360) into x speed and y speed ?

blueznl · Post by **blueznl** » Thu Dec 18, 2003 12:21 pm

you mean a vector (angle + distance) to x / y components?

x = z * cos( a )
y = z * sin ( a )

Psychophanta · Post by **Psychophanta** » Thu Dec 18, 2003 12:32 pm

Hi Deglor. Without any sort of doubts, for me the best way to work with movement in 2D or 3D is using "director vectors".

Listen: in 2D with 2 only parameters (v0,v1) ("director vector" is how i call it) you have the instant direction and real speed (which is hipotenuse of both paramaters) of the object. And of course: x speed=v0 ; y speed=v1

how do you convert a angle (0-360) into x speed and y speed ?

there are several methods to convert polar coordenates to rectangular ones. Trigonometrical method should be fastest using FPU, but if you have not FPU, the best could be geometrical method.
To know it you need not only angle, but modulo too:
x speed=modulo*cos(angle)
y speed=modulo*sin(angle)

blueznl · Post by **blueznl** » Thu Dec 18, 2003 7:08 pm

hey psycho, i should have said that i used 'z' for the speed

Psychophanta · Post by **Psychophanta** » Thu Dec 18, 2003 8:56 pm

Sorry, i began writting it before you finished

Dreglor · Post by **Dreglor** » Thu Dec 18, 2003 11:00 pm

ok thanks
i haven't learn trig yet :roll:

DriakTravo · Post by **DriakTravo** » Fri Dec 19, 2003 3:28 pm

I am trying to do the same thing. How do you find the angle of elevation?

GedB · Post by **GedB** » Fri Dec 19, 2003 7:00 pm

Ian Bell, co-author of the legendary Elite, has provided a shareware Maths for Programmers tutorial.

It can be heavy going, but this guy knows what his talking about.

http://www.iancgbell.clara.net/maths/index.htm

dontmailme · Post by **dontmailme** » Fri Dec 19, 2003 7:18 pm

Thats a great site

I didn't know about the maths bit although I regularly visited the site about a year ago 8O

Psychophanta · Post by **Psychophanta** » Fri Dec 19, 2003 7:55 pm

Ouffh! That is hardly explained, and poorly focused to computers and microprocessors.
Surely there are better sites.

DriakTravo · Post by **DriakTravo** » Fri Dec 19, 2003 8:09 pm

WOW! 8O That looks really complicated. Im only in 10th grade and just wanted to know how to find the angle of a right triangle konwing the lengths of the 2 sides. (the mouse x and y coordinants in relation to a point on the screen.)

Any easy answer?!

dontmailme · Post by **dontmailme** » Fri Dec 19, 2003 8:21 pm

Go here http://aleph0.clarku.edu/~djoyce/java/trig/sines.html

It's seems to all be explained there

DriakTravo · Post by **DriakTravo** » Fri Dec 19, 2003 8:37 pm

here is an example of what I am tring to do:

Code: Select all

InitSprite()
InitMouse()

OpenScreen(800,600,32,"")

Structure bullet
  X.f
  Y.f
  XS.f
  YS.f
EndStructure

NewList bullets.bullet()

Procedure Addbullet(X.f,Y.f,XS.f,YS.f)
  AddElement(Bullets())
  Bullets()\X = X
  Bullets()\Y = Y
  Bullets()\XS = XS
  Bullets()\YS = YS
EndProcedure

Global mouseangle, BulletSpeed
BulletSpeed = 10

Procedure GetMouseAngle()
  ;add code here to determine the angle in relation between the mouse coords and the center of the screen.
  ProcedureReturn MouseAngle.f
EndProcedure

Repeat
  ClearScreen(0,0,0)
  ExamineMouse()
  
  If CountList(bullets()) > 1
    ResetList(Bullets())
    While NextElement(Bullets())
      StartDrawing(ScreenOutput())
        Line(Bullets()\X,Bullets()\Y,Bullets()\XS,Bullets()\YS,RGB(Random(255),Random(255),0))
        Circle(MouseX(),MouseY(),2,RGB(0,255,255))
      StopDrawing()
      Bullets()\X + Bullets()\XS
      Bullets()\Y + Bullets()\YS
      If Bullets()\X > 800 + Bullets()\XS
        DeleteElement(Bullets())
      EndIf
      If Bullets()\X < 0 - Bullets()\XS
        DeleteElement(Bullets())
      EndIf
      If Bullets()\Y > 600 + Bullets()\YS
        DeleteElement(Bullets())
      EndIf
      If Bullets()\Y < 0 - Bullets()\YS
        DeleteElement(Bullets())
      EndIf
    Wend
  EndIf
  
  If MouseButton(2) = 1
    End
  ElseIf MouseButton(1) = 1
    Angle = GetMouseAngle()
    SpeedX.f = Sin(GetMouseAngle()*(3.14/180))*10
    SpeedY.f = Cos(GetMouseAngle()*(3.14/180))*10
    dudecounter + 1
    If dudecounter = 10
      dudecounter = 0
      Addbullet(400,300,SpeedX,SpeedY)
    EndIf 
  EndIf
  
  FlipBuffers()
ForEver

Psychophanta · Post by **Psychophanta** » Fri Dec 19, 2003 10:46 pm

DriakTravo; you dont need to work with angles nor with any kind of trigonometry to do that (neither for almost anything to make a game, even very complex game or anything).
However; if you have two point coords in screen, for example A(a1,a2) and B(b1,b2) the angle formed by the vector (A,B) respect the horizontal is:
ACos((b1-a1)/Sqr(Pow((b1-a1),2)+Pow((b2-a2),2)))

If you want in degrees then add *180/3.14592
and be careful, because if A=B (this is: a1=b1 and a2=b2) then division by zero will happen.

MORE:
I can't understand why everybody is obstinated (big game software companies too) in imitating physics and naturals (for example pinball ball movements, sport games, 3D racing, etc, etc).
A computer offers much more than just physic events phenomenon, or nature.

Where are the genius and creativity

Aren't today creators? Real Artists? Only merchants?

Danilo · Post by **Danilo** » Fri Dec 19, 2003 11:37 pm

2 examples by ChaOsKid (german forum):

Code: Select all

;
; by ChaOsKid, 27.06.03  - german forum
;
; http://www.robsite.de/php/pureboard/viewtopic.php?t=1518
;
Procedure.w gATan(a.w, b.w) 
  winkel.w = ATan(a/b)*57.2957795 
  If b < 0 
    winkel + 180 
  EndIf 
  If winkel < 0 : winkel + 360 : EndIf 
  If winkel > 359 : winkel - 360 : EndIf 
  ProcedureReturn winkel 
EndProcedure 

If InitSprite() = 0 Or InitKeyboard() = 0 Or InitMouse() = 0 
  MessageRequester("Error", "DirectX 7 Fehler!", 0) 
  End 
EndIf 

Breite = 800 
Hoehe = 600 

If OpenScreen ( Breite, Hoehe,32,"Standard") = 0 
  MessageRequester("Error", "Es konnte kein Bildschirm aufgebaut werden", 0) 
  End 
EndIf 

If InitSprite3D() = 0 
  MessageRequester("DirectX fehler !", "Fehler", #PB_MessageRequester_Ok) 
  End 
EndIf 


CreateSprite(0, 50, 50, #PB_Sprite_Texture) 
StartDrawing(SpriteOutput(0)) 
  Box(0, 0, 50, 50, RGB(55, 55, 55)) 
  FrontColor(100, 100, 100) 
  DrawingMode(1) 
  Locate(10, 10) 
  DrawText("CK") 
StopDrawing() 

Sprite3DQuality(1) 

CreateSprite3D(0, 0) 

Repeat 
  ClearScreen(0, 0, 0) 
  ExamineMouse() 
  ; a = grÃ¼n 
  a.w = MouseY() - Hoehe/2 
  ; b = rot 
  b.w = MouseX() - Breite/2 
  winkel.w = gATan(a, b) 

  Start3D() 
    RotateSprite3D(0, Winkel, 0) 
    DisplaySprite3D(0, Breite/2 - 25, Hoehe/2 - 25) 
  Stop3D() 
  
  StartDrawing(ScreenOutput()) 
    ; a = grÃ¼n 
    LineXY(MouseX(), MouseY(), MouseX(), Hoehe/2, $00F000) 
    ; b = rot 
    LineXY(MouseX(), Hoehe/2, Breite/2, Hoehe/2, $0000F0) 
    ; c = blau 
    LineXY(Breite/2, Hoehe/2, MouseX(), MouseY(),$500000) 
    DrawingMode(1) 
    FrontColor(255, 0, 0) 
    Locate(MouseX(), Hoehe/2 + 1) 
    DrawText("b: " + Str(b)) 
    FrontColor(0, 255, 0) 
    Locate(MouseX() + 1, MouseY()) 
    DrawText("a: " + Str(a)) 
    FrontColor(255, 255, 255) 
    Locate(Breite/2, Hoehe/2 + 25) 
    DrawText(Str(winkel) + " Grad") 
  StopDrawing() 
  FlipBuffers() 
  
  If ExamineKeyboard() 
    If KeyboardPushed(#PB_Key_Escape) 
      Quit = 1 
    EndIf 
  EndIf 
  Delay(10) 
Until Quit

Code: Select all

;
; by ChaOsKid, 07.07.03 - german forum
;
; http://www.robsite.de/php/pureboard/viewtopic.php?t=1518
;
Structure Spieler 
  x.f 
  y.f 
  hGroesse.l 
  Geschwindigkeit.l 
  DrehGeschwindigkeit.l 
  Winkel.l 
  ZielWinkel.l 
EndStructure 

Structure Geschoss 
  x.f 
  y.f 
  GeschwindigkeitX.f 
  GeschwindigkeitY.f 
EndStructure 

NewList Geschoss.Geschoss() 

Procedure.l gATan(a.l, b.l) 
  winkel.l = Int(ATan(a/b)*57.2957795) 
  If b < 0 
    winkel + 180 
  EndIf 
  If winkel < 0 : winkel + 360 : EndIf 
  If winkel > 359 : winkel - 360 : EndIf 
  ProcedureReturn winkel 
EndProcedure 

Procedure.f gSin(winkel.l) 
   ; Eingabe: Winkel ( 0 - 360 ) 
   ; Ausgabe: Sinus vom Winkel 
   ProcedureReturn Sin(winkel*0.01745329) 
EndProcedure 

Procedure.f gCos(winkel.l) 
   ; Eingabe: Winkel ( 0 - 360 ) 
   ; Ausgabe: Cosinus vom Winkel 
   ProcedureReturn Cos(winkel*0.01745329) 
EndProcedure 

Procedure neuesGeschoss(x.f, y.f, GeschwindigkeitX.f, GeschwindigkeitY.f) 
  AddElement(Geschoss()) 
  Geschoss()\x = x 
  Geschoss()\y = y 
  Geschoss()\GeschwindigkeitX = GeschwindigkeitX 
  Geschoss()\GeschwindigkeitY = GeschwindigkeitY 
EndProcedure 

If InitSprite() = 0 Or InitKeyboard() = 0 Or InitMouse() = 0 
  MessageRequester("Error", "DirectX 7 Fehler!", 0) 
  End 
EndIf 

Breite = 800 
Hoehe = 600 

If OpenScreen ( Breite, Hoehe,32,"Standard") = 0 
  MessageRequester("Error", "Es konnte kein Bildschirm aufgebaut werden", 0) 
  End 
EndIf 

If InitSprite3D() = 0 
  MessageRequester("DirectX fehler !", "Fehler", #PB_MessageRequester_Ok) 
  End 
EndIf 

CreateSprite(0, Breite, Hoehe) 

CreateSprite(1, 32, 32, #PB_Sprite_Texture) 
StartDrawing(SpriteOutput(1)) 
  Box(0, 0, 32, 32, RGB(55, 55, 55)) 
;  Circle(16, 16, 15, RGB(55, 55, 55)) 
  FrontColor(100, 100, 100) 
  DrawingMode(1) 
  Locate(7, 8) 
  DrawText("CK") 
StopDrawing() 

CreateSprite(2, 32, 32, #PB_Sprite_Texture) 
StartDrawing(SpriteOutput(2)) 
  LineXY(1, 17, 16, 1, RGB(255, 255, 255)) 
  LineXY(16, 1, 31, 17, RGB(255, 255, 255)) 
  LineXY(20, 17, 31, 17, RGB(255, 255, 255)) 
  LineXY(10, 17, 1, 17, RGB(255, 255, 255)) 
  LineXY(10, 31, 10, 17, RGB(255, 255, 255)) 
  LineXY(20, 31, 20, 17, RGB(255, 255, 255)) 
  LineXY(10, 31, 20, 31, RGB(255, 255, 255)) 
  LineXY(10, 31, 10, 17, RGB(255, 255, 255)) 
  FillArea(16, 17, RGB(255, 255, 255), RGB(255, 255, 255)) 
StopDrawing() 

Sprite3DQuality(1) 
CreateSprite3D(1, 1) 
CreateSprite3D(2, 2) 

CreateSprite(10, 32, 32) 
StartDrawing(SpriteOutput(10)) 
  DrawingMode(4) 
  Circle(16, 16, 16, RGB(255, 255, 255)) 
  Plot(16, 16,RGB(200, 200, 200)) 
StopDrawing() 


Spieler1.Spieler 
Spieler1\hGroesse = 16 
Spieler1\x = Breite/2 - Spieler1\hGroesse 
Spieler1\y = Hoehe/2 - Spieler1\hGroesse 
Spieler1\Geschwindigkeit = 2 
Spieler1\Drehgeschwindigkeit = 2 
Spieler1\Winkel = 270 

Maus.Point 

Repeat 
  ExamineMouse() 
  ExamineKeyboard() 

  Maus\x = MouseX() - 16 
  Maus\y = MouseY() - 16 
  a.l = Maus\y - Spieler1\y 
  b.l = Maus\x - Spieler1\x 
  Spieler1\ZielWinkel = gATan(a, b) 
  
  If KeyboardPushed(#PB_Key_Left) Or KeyboardPushed(#PB_Key_A) 
    Spieler1\Winkel - Spieler1\Drehgeschwindigkeit 
  EndIf 
  If KeyboardPushed(#PB_Key_Right) Or KeyboardPushed(#PB_Key_D) 
    Spieler1\Winkel + Spieler1\Drehgeschwindigkeit 
  EndIf 
  ; 
  If KeyboardPushed(#PB_Key_Up) Or KeyboardPushed(#PB_Key_W) 
    Spieler1\x + (gCos(Spieler1\Winkel) * Spieler1\Geschwindigkeit) 
    Spieler1\y + (gSin(Spieler1\Winkel) * Spieler1\Geschwindigkeit) 
  EndIf 
  If KeyboardPushed(#PB_Key_Down) Or KeyboardPushed(#PB_Key_S) 
    Spieler1\x - (gCos(Spieler1\Winkel) * Spieler1\Geschwindigkeit) 
    Spieler1\y - (gSin(Spieler1\Winkel) * Spieler1\Geschwindigkeit) 
  EndIf 
  If Spieler1\x > Breite - 32 
    Spieler1\x = Breite - 32 
  EndIf 
  If Spieler1\x < 0 
    Spieler1\x = 0 
  EndIf 
  If Spieler1\y > Hoehe - 32 
    Spieler1\y = Hoehe - 32 
  EndIf 
  If Spieler1\y < 0 
    Spieler1\y = 0 
  EndIf 
  
  If MouseButton(1) 
    If Verzoegerung < 1 
      Verzoegerung = 10 
      Geschwindigkeit.l = 8 
      Geschossabstand.l = 33 
      GeschwindigkeitX.f = gCos(Spieler1\ZielWinkel) 
      GeschwindigkeitY.f = gSin(Spieler1\ZielWinkel) 
      neuesGeschoss(Spieler1\x + Spieler1\hGroesse + GeschwindigkeitX * Geschossabstand, Spieler1\y + Spieler1\hGroesse + GeschwindigkeitY * Geschossabstand, GeschwindigkeitX * Geschwindigkeit, GeschwindigkeitY * Geschwindigkeit) 
      ;patronenhÃ¼lse malen 
      StartDrawing(SpriteOutput(0)) ;Grafiken werden direkt auf dem Hintergrundbildsprite gerendert 
        Plot(Int(Spieler1\x) + Random(Spieler1\hGroesse) + Spieler1\hGroesse/2, Int(Spieler1\y) + Random(Spieler1\hGroesse) + Spieler1\hGroesse/2, RGB(200, 120, 55)) 
      StopDrawing() 
    EndIf 
  EndIf 
  If Verzoegerung > 0 
    Verzoegerung - 1 
  EndIf 
  
  ;ClearScreen(0, 0, 0) 
  
  DisplaySprite(0, 0, 0) 

  Start3D() 
    RotateSprite3D(1, Spieler1\Winkel, 0) 
    DisplaySprite3D(1, Int(Spieler1\x), Int(Spieler1\y)) 
    RotateSprite3D(2, Spieler1\ZielWinkel, 0) 
    DisplaySprite3D(2, Int(Spieler1\x), Int(Spieler1\y), 20) 
  Stop3D() 
  
  DisplayTransparentSprite(10, Maus\x, Maus\y) 

  ; Geschosse rendern 
  StartDrawing(ScreenOutput()) ;Grafiken werden direkt auf dem Bildschirm gerendert 
    
    ResetList(Geschoss()) 
    While NextElement(Geschoss()) 
      If Geschoss()\x < 0 Or Geschoss()\y < 0 Or Geschoss()\x > Breite Or Geschoss()\y > Hoehe 
        DeleteElement(Geschoss()) 
      Else 
        Plot(Int(Geschoss()\x), Int(Geschoss()\y), RGB(200, 200, 200)) 
        LineXY(Int(Geschoss()\x - Geschoss()\GeschwindigkeitX*2), Int(Geschoss()\y - Geschoss()\GeschwindigkeitY*2), Geschoss()\x, Geschoss()\y, RGB(120, 100, 100)) 
        Geschoss()\x + Geschoss()\GeschwindigkeitX 
        Geschoss()\y + Geschoss()\GeschwindigkeitY 
      EndIf 
    Wend 
  StopDrawing() 
  
  FlipBuffers() 
    
  If KeyboardPushed(#PB_Key_Escape) 
    Quit = 1 
  EndIf 

  Delay(3) 
Until Quit

Another example by Rob (german forum):
(Cursor Keys to move, space = shoot)

Code: Select all

;
; by Rob, 03.10.2003 - german forum
;
; http://www.robsite.de/php/pureboard/viewtopic.php?t=2449&start=11
;
; Screen 
xscreen = 640 
yscreen = 480 

; Kreis 
k_x.f = xscreen/2 
k_y.f = yscreen/2 
k_winkel.f = 180 
k_radius = 15 
k_speed.f = 2 

; SchÃ¼sse 
Structure kugel 
  x.f 
  y.f 
  winkel.f 
  speed.f 
EndStructure 

NewList schuss.kugel() 


InitKeyboard() 
InitSprite() 

If OpenScreen(xscreen,yscreen,16,"Schusstest") 
    
  Repeat 
    ExamineKeyboard() 
    
    ; Kreis bewegen 
    ; Drehen 
    If KeyboardPushed(#PB_Key_Left) : k_winkel - 4 :  If k_winkel <= 0 : k_winkel = 360 : EndIf : EndIf 
    If KeyboardPushed(#PB_Key_Right) : k_winkel + 4 : If k_winkel >= 360 : k_winkel = 0 : EndIf : EndIf 
    
    ; VorwÃ¤rts 
    If KeyboardPushed(#PB_Key_Up) 
      k_x + Cos(k_winkel *(2*3.1415/360)) * k_speed ; Grad zu BogenmaÃŸ 
      k_y + Sin(k_winkel *(2*3.1415/360)) * k_speed 
    EndIf 
    
    ; RÃ¼ckwÃ¤rts 
    If KeyboardPushed(#PB_Key_Down) 
      k_x + Cos(k_winkel *(2*3.1415/360)) * -k_speed 
      k_y + Sin(k_winkel *(2*3.1415/360)) * -k_speed 
    EndIf    
    
    ; Schuss abfeuern 
    If KeyboardPushed(#PB_Key_Space) And geschossen = 0 
      AddElement(schuss()) 
      schuss()\x = k_radius * Cos(k_winkel *(2*3.1415/360)) + k_x ; Am Rand des Kreises 
      schuss()\y = k_radius * Sin(k_winkel *(2*3.1415/360)) + k_y 
      schuss()\winkel = k_winkel 
      schuss()\speed = 5 
      
      geschossen = 1 ; Erst die Taste wieder loslassen, kein Dauerfeuer 
    EndIf 
    
    If KeyboardReleased(#PB_Key_Space) : geschossen = 0 : EndIf 
    
    ; SchÃ¼sse bewegen 
    ResetList(schuss()) 
    While NextElement(schuss()) 
      schuss()\x + Cos(schuss()\winkel *(2*3.1415/360)) * schuss()\speed 
      schuss()\y + Sin(schuss()\winkel *(2*3.1415/360)) * schuss()\speed 
      
      ; Kommen sie am Rand an, lÃ¶schen 
      If schuss()\x > xscreen Or schuss()\x < 0 Or schuss()\y > yscreen Or schuss()\y < 0 
        DeleteElement(schuss()) 
      EndIf 
      
    Wend 
    
    ; ------------------------------ 
    
    ; Zeichnen 
    StartDrawing(ScreenOutput()) 
    
    ; Kreis 
    DrawingMode(4) 
    Circle(k_x,k_y,k_radius,RGB(0,100,255)) 
    LineXY(k_x,k_y,k_radius * Cos(k_winkel *(2*3.1415/360)) + k_x,k_radius * Sin(k_winkel *(2*3.1415/360)) + k_y,RGB(0,255,255)) 
    
    ; SchÃ¼sse 
    ResetList(schuss()) 
    While NextElement(schuss()) 
      LineXY(schuss()\x,schuss()\y,8 * Cos(schuss()\winkel *(2*3.1415/360)) + schuss()\x,8 * Sin(schuss()\winkel *(2*3.1415/360)) + schuss()\y,RGB(255,100,0)) 
    Wend 
    
     ; Text 
    DrawingMode(1) 
    FrontColor(150,150,150) 
    Locate(1,1) 
    DrawText("Winkel: " + Str(k_winkel)) 
    Locate(1,16) 
    DrawText("SchÃ¼sse: " + Str(CountList(schuss())))    
      
    StopDrawing() 
    
    FlipBuffers() 
    ClearScreen(0,0,0) 
  Until KeyboardPushed(#PB_Key_Escape)
Else 
  MessageRequester("Error","Funzt nich",0) 
EndIf

btw: Winkel in Grad (german) = Angle in Degree (english)

Maybe this helps a little bit with angle calculation.
Sometimes real examples are better than all the theorie...
especially for starters.