DrawOval(100,100,99,33,RGB(255,0,0))
SHOWSCREEN
MOUSEWAIT
FUNCTION DrawOval%: x, y, w, h, col%
INC x, w/2
INC y, h/2
LOCAL phi
STARTPOLY -1, 0
POLYVECTOR x,y, 0,0,col
FOR phi = 0 TO 360 STEP 5 // how poly do you want it?
POLYVECTOR x+COS(phi)*w, y-SIN(phi)*h, 0,0,col
NEXT
ENDPOLY
ENDFUNCTION
Keywords: draw ellipse, draw oval, drawoval, drawellipse, circle, elipse
Ah, that's easy Gernot - but an internal function... ;)
Cheers anyway :)
Quote from: Kitty Hello on 2010-May-04
FOR phi = 0 TO 360 STEP 5 // how poly do you want it?
Then you have 361Ã,° ?
no. First point is at 0Ã,°, last point is at 360Ã,°, which is the same as 0Ã,° (close the circle)
ooops right, my bad :D
Thanks Gernot.
How fast is this function?
for opengl(es) platforms, fastest possible. For wiz/pocketpc you might be faster with a drawrect method.
This dont work as expected, it should be:
FUNCTION DrawOval%: x, y, w, h, col%
w = w/2
h = h/2
INC x, w
INC y, h
STARTPOLY -1, 0
POLYVECTOR x,y, 0,0,col
FOR phi = 0 TO 360 STEP 5 // how poly do you want it?
POLYVECTOR x+COS(phi)*w, y-SIN(phi)*h, 0,0,col
NEXT
ENDPOLY
ENDFUNCTION
Or if you want to include drawing arcs:
FUNCTION DrawOval%: x, y, w, h, col%, arc=360, arcs=0 // arc MUST be >0! arcs=starting of the arc 0=top
w = w/2
h = h/2
INC x, w
INC y, h
INC arcs, 90
INC arc, arcs
STARTPOLY -1, 0
POLYVECTOR x,y, 0,0,col
FOR phi = arcs TO arc STEP 5 // how poly do you want it?
POLYVECTOR x+COS(phi)*w, y-SIN(phi)*h, 0,0,col
NEXT
ENDPOLY
ENDFUNCTION
If you need more speed, change the STEP 5 to higher number or try QSIN and QCOS.