Something weird with mouse x y and sprite

Hi Ben.

I think the problem is that Mouse_Button(MOUSE_LBUTTON) will keep returning true for as long as the button is being held down. Whereas you only want to move your center point when the button is first pressed.
I've added a couple of variables to detect this case. Basically it tracks whether the mouse button was pressed the last time around the loop. If it wasn't pressed last time but is pressed now, then you have a button click, and can move your point.

ResizeSpriteArea(400,500)
TextMode(TEXT_BUFFERED)
BACKGROUNDCOLOR(0,0,0)

'loading generic sprite for testing
dim g= LoadTex("gfx/Ball.png")
dim c1= NewSprite(g)
SprSetSize(8,8)
SprSetPos(200,250)

dim d1=NewSprite(g)
SprSetSize(8,8)
SprSetPos(210,260)

dim mx,my,r as double,sx as double,sy as double,cx,cy,radA as double,dx as double,dy as double
dim buttonDown, buttonWasDown

'starting centor location
cx=200
cy=250
r=50 'radius

while true

   'get mouse location
mx = Mouse_X() * 400
my = Mouse_Y() * 500

   'convert to radian angle
   radA = atn2(mx-cx,my-cy)

   'convert to cos and sin values
dx=sin(radA)
   dy=cos(radA)

   'set angle radains * radius
   sx=cx+(dx*r)
   sy=cy+(dy*r)

buttonDown = Mouse_Button(MOUSE_LBUTTON)
if buttonDown and not buttonWasDown then ' New click

    'set distance to move center sprite
     cx=cx+(dx*r)
     cy=cy+(dy*r)

    'move center sprite
     bindsprite(c1)
     sprsetpos(cx,cy)

    'go back to direction sprite
    bindsprite(d1)

   'show new values of center sprite
locate 0,0:print "cx: ";cx;" cy: ";cy
locate 0,1:print "mx: ";mx;" my: ";my
endif

   'set new dir sprite location
   sprsetpos(sx,sy)

'draw it.
DrawText()

buttonWasDown = buttonDown
wend