Camera behind a moving object (tomb raider style)

I would do something like this:
all floats

x=entityx(player)+sin(entityyaw(player)+180)*10
y=entityy(player)+4
z=entityz(player)+cos(entityyaw(player)+180)*10
xc=entityx(camera)
yc=entityy(camera)
zc=entityz(camera)
xc=(xc+(x-xc))/5
yc=(yc+(y-yc))/5
zc=(zc+(z-zc))/5

positionentity camera,xc,yc,zc
pointentity camera,player
while (camerapick(graphicswidth()/2,graphicsheight()/2)<> player) and (entitydistance(camera,player)>2)
 moveentity camera,0,0,.5
 positionentity camera,entityx(camera),entityy(player)+4,entityz(camera)
 pointentity camera,player
wend
...