ATanFull - Learn To Code - PlayBASIC Documentation

ATanFull

Degrees# = ATanFull(Y, X)

Parameters:

Y = The value representing the y-coordinate of a point.
X = The value representing the x-coordinate of a point.

Returns:

Degrees# = Angle in degrees range between (-180 to 180)

ATanFull calculates the arc tangent of the two variables Y and X. It is similar to calculating the arc tangent of X / Y, except that the signs of both arguments are used to determine the quadrant of the result.

ATanFull can be used to aim one sprite at another. For example, if Sprite #1 is at the point(X1, Y1), and Sprite #2 is at point (X2, Y2), ATanFull(Y1-Y2. X1-X2) will return an angle (in degrees) that can be used to rotate Sprite #2 so that it aims at Sprite #1.

FACTS:

     * In some programming languages ATanFull is called ATan2

     * Notice the order of the parameters Y and X.

     * Also See GetAngle2D and WrapAngle if want the angle to be within 0 to 360

Mini Tutorial:

; Create a coloured image
  Cls RGB(0,255,0)
  Image = GetFreeImage()
  GetImage Image,0,0,64,32
  PrepareFXImage Image

; Calculate the position of the sprite
  SpriteXPos = GetScreenWidth() / 2
  SpriteYPos = GetScreenHeight() - 100


; Create a sprite and assign the image
  Sprite =NewSprite(SpriteXPos,SpriteYPos,image)
  SpriteDrawMode Sprite,2
  SpriteHandle Sprite,(GetImageWidth(Image)/2)*-1,(GetImageHeight(Image)/2)*-1

; align the sprite to the current mouse position
  Repeat
     Cls RGB(0,0,0)

   ; calc the angle from the spites position to the mousex
     angle# = ATanFull( MouseY()-SpriteYPos, MouseX() - SpriteXPos)
     RotateSprite Sprite, angle#

   ; Draw All the Sprites
     DrawAllSprites

     Sync
  Until EscKey()


Related Info:	AngleDifference \| Atan \| CurveAngle \| GetAngle2D \| GetDistance2D \| Tan \| TurnDirection \| WrapAngle :