>Segment3
 : Cy Booker
 : 86 Church View
 : Main Road
 : Crockenhill
 : Swanley
 : Kent
 : BR8 8 JW
     Test algorithm for drawing an hsv cone dynamically
 Instead of drawing curves, we draw quadrangles
 We pre-calculate all trig multiplications
 The circle is split into NT% = 8*2^N% angles [N% = 0, 1, 2, 3]
 The outer radius is R [= Radius * Value]
 Each annulus is DR% wide
 There are NA% annuli = floor(R / DR%)
 Note tried just storing points at corners of each quadrangle
 but this results in too much screen overwriting, so now going
 to store for each quadrangle the four points, suitably grown
 in one half pixel
 No, this leaves some gaps, so trying to align to 2 OS unit "pixel" grid
 No, if align all up to 2 pixel grid, at least leaves no gaps
     Note that for radius R, the max distance between straight line and
     actual radius occurs when N% = 0, and get d = r*(1-COS(PI/8))
     which for r= 128 => d= 9.74
 The above means when try blanking out need to add 10 OS units to radius
 to ensure blank all
  This produces a nice demo of the finnished program
     The lhs is the value bar, click with mouse to set value
$+ " {"+ 
)+ "}"
"7Value = -1                      :
 0 <= Value < 1.0
#BRadius = 127.5                  :
 Radius of cone, in OS units
$AN% = 0                          :
 measure of accuracy [0, 3]
%4HalfPixel% = 1                  :
 min(x,y half)
&$EigthHue%   = (360 * &10000) / 8
RadiusFudge = 10
SegmentPartsPerFrame% = 13
 X%(8-1, 32-1, 3)
 Y%(8-1, 32-1, 3)
 Hue%(8-1)
 Saturation%(32-1)
 Drawn%(32*8*8 - 1)
/5DisplayedRadius = -1            :
 sentinel value
 "Wimp_SetColour", 1
 512, 512
 -512, -512, 40, 1024
_Change_Value(1.00)
 x%, y%, b%
9+   
_Change_Value((y%+512)/1024)
_Update_HSV
_Update_HSV
 n%, i%, j%
 NA% = 0 
 NToDraw% = 0 
 N% = 3 
    N% += 1
_Calc_HSV_Constants
F   n% = SegmentPartsPerFrame%
 n% > NToDraw% 
 n% = NToDraw%
 n%=0 
 1, "ASSERT"
 i%= 1 
JC    j%= 
(NT%*NA%) - 2                :
 now in range [-1, n-1)
K	    
      j% += 1
M'    
 j%=(NT%*NA%-1) 
 Drawn%(j%)
 Drawn%(j%) 
O$      j%=0:
 Drawn%(j%):j%+=1:
P'      
 j%>=NT%*NA% 
 1, "ASSERT"
Q	    
R.    
_Draw_SegmentPart(j% 
 NT%, j% 
 NT%)
    Drawn%(j%) = 
  NToDraw% -= n%
W	:    
_Change_Value(v)
 v%, c%, x0, x1, x2, x3, y0, y1, y2, y3
 Value=v 
  Value = v
 "Wimp_SetColour", 12
  v% = Value * 1024
 -512, -512, 40, v%
 "Wimp_SetColour", 11
 -512, -512+v%, 40, 1024
  R = Radius * Value
bG  N% = 0                                        :
 start off coarse
_Calc_HSV_Constants
 DisplayedRadius > R 
e(    
 now must immediately blank out
 "Wimp_SetColour", 1
 NA% >= 1 
h(      x0 = R                : y0 = 0
i(      x1 = DisplayedRadius  : y1 = 0
      
 t%= 1 
        t = 2*
*(t%/15)
        cos = 
        sin = 
n1        x2 = R*cos               : y2 = R*sin
o?        x3 = DisplayedRadius*cos : y3 = DisplayedRadius*sin
        
 x0, y0
        
 x1, y1
        
 &55, x2, y2
        
 x3, y3
        
 &55, x1, y1
        x0 = x2 : y0 = y2
        x1 = x3 : y1 = y3
      
x	    
y%      
 0, 0, DisplayedRadius
z	    
|7  :
 draw grey center of cone (greyness is "value")
  c% = (Value*255) + 0.5
 "ColourTrans_SetGCOL", (c% * &010101) << 8,,,&100,0
 0, 0, R - DR%*NA%
'  DisplayedRadius = R + RadiusFudge
_Calc_HSV_Constants
A  OT% = 1 << N%                   :
 #divisions in one octant
C  NT% = 8 * OT%                   :
 #divisions in whole circle
:  DR% = 32 
 OT%                :
 size of each annuli
:  NA% = 
floor(R, DR%)           :
 #annuli (complete)
 NA% >= 1 
_Calc_Octant
_Calc_Octant
 a%, t%, a, cos, r, sin, t
 a%= 0 
 NA%-1
,    :
 get radius of middle of annuli a%
(    r = (R - (a% * DR%)) - (DR% / 2)
2    Saturation%(a%) = ((r / R) * &10000) + 0.5
 t%= 0 
 OT%-1
5    :
 angle in middle of segment in range (0, 1)
    t = (t% + 0.5) / OT%
1    Hue%(t%) = (360 * &10000 * (t / 8)) + 0.5
%  Value% = (Value * &10000) + 0.5
  delta = 
(HalfPixel% / R)
 t%= 0 
 OT%-1
    :
 angles {0, .., PI/4}
!    tmin = (
/4) * (t% / OT%)
#    tmax = tmin + ((
/4) / OT%)
    cosmin = 
(tmin)
    sinmin = 
(tmin)
    cosmax = 
(tmax)
    sinmax = 
(tmax)
 a%= 0 
 NA%-1
      rmax = R - (a% * DR%)
      rmin = rmax - DR%
/      X%(t%, a%, 0) = 
roundup(rmin*cosmin)
/      Y%(t%, a%, 0) = 
roundup(rmin*sinmin)
/      X%(t%, a%, 1) = 
roundup(rmax*cosmin)
/      Y%(t%, a%, 1) = 
roundup(rmax*sinmin)
/      X%(t%, a%, 2) = 
roundup(rmax*cosmax)
/      Y%(t%, a%, 2) = 
roundup(rmax*sinmax)
/      X%(t%, a%, 3) = 
roundup(rmin*cosmax)
/      Y%(t%, a%, 3) = 
roundup(rmin*sinmax)
  Drawn%() = 
  NToDraw% = NT% * NA%
 [-1 .. +1) --> 0
round(x)
((x / 2) + 0.5) * 2
roundup(x)
= 2 * 
ceiling(x, 2)
rounddown(x)
= 2 * 
floor(x, 2)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 integer round x/y towards +infinity
ceiling(x, y)
x <> 
    x = x / y
    x = 
 x <> 
    x = 1 + 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 integer round x/y towards -infinity
floor(x, y)
x <> 
    x = -
    x = x / y
_Draw_SegmentPart(a%, t%)
 x0%,x1%,x2%,x3%, y0%,y1%,y2%,y3%, hue%, saturation%
_Draw_SegmentPart_Point(x0%,y0%, a%, t%, 0)
_Draw_SegmentPart_Point(x1%,y1%, a%, t%, 1)
_Draw_SegmentPart_Point(x2%,y2%, a%, t%, 2)
_Draw_SegmentPart_Point(x3%,y3%, a%, t%, 3)
6  hue% = Hue%(t% 
 OT%) + ((t% 
 OT%) * EigthHue%)
 hue% >= 360*&10000 
 1, "ASSERT"
 hue% <= 0 
 1, "ASSERT"
#  saturation% = Saturation%(a%)
 "ColourTrans_ConvertHSVToRGB", hue%, saturation%, Value% 
 red%, green%, blue%
  red%   = 
rgb(red%) << 8
!  green% = 
rgb(green%) << 16
   blue%  = 
rgb(blue%) << 24
 "ColourTrans_SetGCOL", red% 
 green% 
 blue%,,, &100, 0
 x0%, y0%
 x1%, y1%
 &55, x2%, y2%
 x3%, y3%
 &55, x0%, y0%
   MOVE x0%, y0%
   DRAW x1%, y1%
   DRAW x2%, y2%
   DRAW x3%, y3%
   DRAW x0%, y0%
rgb(A%)
&  A% = ((A% * 255) / &10000) + 0.5
 A% < 0 
 1 , "negative"
 A% > 255 
 1, "too big"
_Draw_SegmentPart_Point(
 x%, 
 y%, a%, t%, i%)
  x% = X%(t% 
 OT%, a%, i%)
  y% = Y%(t% 
 OT%, a%, i%)
  t% = t% 
 t% > 7 
 1, "bad t%"
  t% = t% 
 (t% >> 1)
 x%, y%
 x% = -x%
 y% = -y%