' TassyJim
' spinning knob test
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
OPTION EXPLICIT
DIM knob_x = 120, knob_y = 120, knob_radius = 80, finger_radius = 20
DIM INTEGER knob_fill = RGB(178, 211, 213), knob_edge = RGB(024, 087, 197)
DIM n, r, angle, tx,ty
CLS

FOR n = 0 TO 360 STEP 15
r=knob_draw(knob_x,knob_y,RAD(n))
PAUSE 100
NEXT n

DO
tx=(TOUCH(X)- knob_x)
ty=(TOUCH(Y)- knob_y)
IF ABS(tx) < (knob_radius+30) AND ABS(ty) < (knob_radius+30) THEN
SELECT CASE tx
CASE 0
IF ty<0 THEN
angle = PI
ELSE
angle = 0
ENDIF
CASE < 0
angle = ATN(ty/tx)+PI/2
CASE ELSE
angle = ATN(ty/tx)+PI*1.5
END SELECT
PRINT tx," ",ty," ", DEG(angle) 'DEBUG
r=knob_draw(knob_x,knob_y,angle)
ELSE
PAUSE 100
ENDIF
PAUSE 100
LOOP

END

FUNCTION knob_draw(x,y,a)
LOCAL fingerX, fingerY
CIRCLE x, y, knob_radius,6 , , knob_edge, knob_fill ' clear knob
fingerX=x-SIN(a)*(knob_radius-finger_radius)
fingerY=y+COS(a)*(knob_radius-finger_radius)
CIRCLE fingerX, fingerY, finger_radius, 6, , knob_edge, knob_fill ' draw marker
END FUNCTION