Posts: 2,693
Threads: 326
Joined: Apr 2022
Reputation:
217
10-12-2024, 09:07 PM
(This post was last modified: 10-13-2024, 03:08 AM by SMcNeill.)
As Terry pointed out elsewhere, CIRCLE has always been broken when it comes to doing arcs for us to fill. I thought I'd give a quick shot at tossing something together to work for us, and here's what I came up with. (Not tested extensively so may break with various angles/combos. I hope not.)
Code: (Select All)
Screen _NewImage(1280, 720, 32)
$Color:32
PieSlice 100, 100, 100, 45, 0, Red
PieSlice 200, 200, 50, 270, 120, Green
PieSlice 300, 300, 50, 120, 270, Gold
Sub PieSlice (cx As Long, cy As Long, r As Long, startAngle As Long, endAngle As Long, c As _Unsigned Long)
Dim As Long x, y, x1, y1
If startAngle > endAngle Then endAngle = endAngle + 360
x1 = Sin(_D2R(startAngle + 90)) * r
y1 = Cos(_D2R(startAngle + 90)) * r
Line (cx, cy)-Step(x1, y1), c
For i = startAngle To endAngle Step Sgn(endAngle - startAngle)
x = Sin(_D2R(i + 90)) * r
y = Cos(_D2R(i + 90)) * r
Line -(cx + x, cy + y), c
If x <> x1 And y <> y1 And xt = 0 Then 'chose a point inside the arc to fill
xt = Sin(_D2R(i + 90)) * r / 2
yt = Cos(_D2R(i + 90)) * r / 2
End If
Next
Line -(cx, cy), c
Paint (cx + xt, cy + yt), c
End Sub
Posts: 3,932
Threads: 175
Joined: Apr 2022
Reputation:
215
Posts: 3,932
Threads: 175
Joined: Apr 2022
Reputation:
215
Ah now I see where North = 0 probably started. I never messed around much with arcs from the Circle Sub.
b = b + ...
Posts: 3,932
Threads: 175
Joined: Apr 2022
Reputation:
215
10-13-2024, 02:53 AM
(This post was last modified: 10-13-2024, 02:54 AM by bplus.)
@SMcNeill your code had a typo on line 17
Line -(cx + x, cx + y), c
should be cy + y
The error didn't show up because your test code used same x, y center point.
And I can't for the life of me figure out what compass you are using for start and finish angles???
It's not Terry's North = 0 nor my Basic East = 0
Code: (Select All) $Color:32
Screen _NewImage(1200, 600, 32)
_ScreenMove 40, 60
Dim degree10, xc1, xc, yc, xc2, r, a, x1, y1, at, sa$, xoff, yoff, x2, y2
degree10 = _Pi(2 / 36) ' like hours on clock
xc1 = 300: xc2 = 900: yc = 300: r = 200
_PrintString (xc1 - _PrintWidth("Regular East = 0 Deg/Rads Calcs") / 2, 292), "Regular East = 0 Deg/Rads Calcs"
_PrintString (xc2 - _PrintWidth("Terry's North = 0 Deg/Rads Calcs") / 2, 292), "Terry's North = 0 Deg/Rads Calcs"
For a = 0 To _Pi(1.999) Step degree10
' Regular East = 0 calcs
x1 = xc1 + r * Cos(a)
y1 = yc + r * Sin(a)
at = Int(_R2D(_Atan2(y1 - yc, x1 - xc1)) + .0001)
If at < 0 Then at = at + 360
sa$ = _Trim$(Str$(at))
xoff = _PrintWidth(sa$) / 2
yoff = 16 / 2
_PrintString (x1 - xoff, y1 - yoff), sa$
' North = 0 calcs
x2 = xc2 + r * Sin(a)
y2 = yc + r * -Cos(a)
at = Int(_R2D(ATan4North0(y2 - yc, x2 - xc2)) + .0001)
If at < 0 Then at = at + 360
sa$ = _Trim$(Str$(at))
xoff = _PrintWidth(sa$) / 2
yoff = 16 / 2
_PrintString (x2 - xoff, y2 - yoff), sa$
Next
pieSliceFill 80, 90, 80, _D2R(45), 0, Red
pieSliceFill 200, 200, 50, _D2R(270), _D2R(120), Green
pieSliceFill 400, 400, 50, _D2R(120), _D2R(270), Gold
PieSliceSteve 620, 90, 80, 45, 0, Red
PieSliceSteve 800, 200, 50, 270, 120, Green
PieSliceSteve 1000, 400, 50, 120, 270, Gold
Locate 33, 1: Print "pieSliceFill 80, 90, 80, _D2R(45), 0, Red";
Locate 34, 1: Print "pieSliceFill 200, 200, 50, _D2R(270), _D2R(120), Green";
Locate 35, 1: Print "pieSliceFill 400, 400, 50, _D2R(120), _D2R(270), Gold";
Locate 33, 76: Print "PieSliceSteve 620, 90, 80, 45, 0, Red";
Locate 34, 76: Print "PieSliceSteve 800, 200, 50, 270, 120, Green";
Locate 35, 76: Print "PieSliceSteve 1000, 400, 50, 120, 270, Gold";
Sub PieSliceSteve (cx As Long, cy As Long, r As Long, startAngle As Long, endAngle As Long, c As _Unsigned Long)
Dim As Long x, y, x1, y1
If startAngle > endAngle Then endAngle = endAngle + 360
x1 = Sin(_D2R(startAngle + 90)) * r
y1 = Cos(_D2R(startAngle + 90)) * r
Line (cx, cy)-Step(x1, y1), c
For i = startAngle To endAngle Step Sgn(endAngle - startAngle)
x = Sin(_D2R(i + 90)) * r
y = Cos(_D2R(i + 90)) * r
Line -(cx + x, cy + y), c ' <<< bplus fixed cy + y not cx + y !!!!
If x <> x1 And y <> y1 And xt = 0 Then 'chose a point inside the arc to fill
xt = Sin(_D2R(i + 90)) * r / 2
yt = Cos(_D2R(i + 90)) * r / 2
End If
Next
Line -(cx, cy), c
Paint (cx + xt, cy + yt), c
End Sub
Function ATan4North0 (dy, dx)
ATan4North0 = _Pi - _Atan2(dx, dy) ' this was totally unexpected!
End Function
Sub pieSlice (x, y, r, raStart, raStop, c As _Unsigned Long)
Dim px As Single, py As Single
arcC x, y, r, raStart, raStop, c ' this does check raStart and raStop
px = x + r * Cos(raStart): py = y + r * Sin(raStart)
Line (x, y)-(px, py), c
px = x + r * Cos(raStop): py = y + r * Sin(raStop)
Line (x, y)-(px, py), c
End Sub
Sub pieSliceFill (x, y, r, raStart, raStop, c As _Unsigned Long)
Dim As Single px, py, raMid
arcC x, y, r, raStart, raStop, c ' this does check raStart and raStop
px = x + r * Cos(raStart): py = y + r * Sin(raStart)
Line (x, y)-(px, py), c
px = x + r * Cos(raStop): py = y + r * Sin(raStop)
Line (x, y)-(px, py), c
raMid = (raStop + raStart) / 2
px = x + r * Cos(raMid): py = y + r * Sin(raMid)
If Point(px, py) <> c Then
raMid = raMid + _Pi
px = x + r / 2 * Cos(raMid): py = y + r / 2 * Sin(raMid)
Else
px = x + r / 2 * Cos(raMid): py = y + r / 2 * Sin(raMid)
End If
Paint (px, py), c
End Sub
Sub arcC (x, y, r, raStart, raStop, c As _Unsigned Long) ' updated 2021-09-09 checks raBegin and raEnd
' raStart is first angle clockwise from due East = 0 degrees
' arc will start drawing there and clockwise until raStop angle reached
'x, y origin, r = radius, c = color
Dim p, p2 ' update 2021-09-09 save some time by doing _pi function once
p = _Pi: p2 = p * 2
Dim dStart, dStop, al, a
' Last time I tried to use this SUB it hung the program, possible causes:
' Make sure raStart and raStop are between 0 and 2pi.
' This sub does not have to be recursive, use GOSUB to do drawing to execute arc in one call.
' changing to equivalents
While raStart < 0: raStart = raStart + p2: Wend
While raStart >= p2: raStart = raStart - p2: Wend
While raStop < 0: raStop = raStop + p2: Wend
While raStop >= p2: raStop = raStop - p2: Wend
If raStop < raStart Then
dStart = raStart: dStop = p2 - .00001
GoSub drawArc
dStart = 0: dStop = raStop
GoSub drawArc
Else
dStart = raStart: dStop = raStop
GoSub drawArc
End If
Exit Sub
drawArc:
al = p * r * r * (dStop - dStart) / p2
For a = dStart To dStop Step 1 / al
PSet (x + r * Cos(a), y + r * Sin(a)), c
Next
Return
End Sub
b = b + ...
Posts: 2,693
Threads: 326
Joined: Apr 2022
Reputation:
217
You guys are weird.
All I was ever taught in school was a simple circle with 0 = east, 90 = north, 180 = west, 270 = south. As such:
Now, isn't this the same as what everyone else was taught in school?
X axis gets larger going from right to left.
Y axis gets larger going from bottom to top.
Posts: 300
Threads: 16
Joined: Apr 2022
Reputation:
51
west virginia curriculum in full effect
Posts: 3,932
Threads: 175
Joined: Apr 2022
Reputation:
215
So your East = 0 but you go Counter-Clockwise Yikes!
Like to see an Atan2 for that! LOL
b = b + ...
Posts: 2,693
Threads: 326
Joined: Apr 2022
Reputation:
217
As you can see from below, the red circle goes from 45 degrees to 0 degrees.
The green circle goes from 270 to 120 degrees.
And the gold circle goes from 120 to 270 degrees. (to show that we can have either slice of the pie that we want.)
Compare the image below to the coordinate system above, and see if it doesn't make perfect sense.
Posts: 3,932
Threads: 175
Joined: Apr 2022
Reputation:
215
Yeah I can see it now that I know where 0 is and which way around you are going.
We are getting similar figures just rotated different or mirror images on x-axis.
b = b + ...
Posts: 2,693
Threads: 326
Joined: Apr 2022
Reputation:
217
(10-13-2024, 03:11 AM)bplus Wrote: So your East = 0 but you go Counter-Clockwise Yikes!
Like to see an Atan2 for that! LOL
Your wish is my command. It's just a little rotation of the result.
Just use the Atan command packaged here so it gives results in Degrees as you'd normally want to see and work with.
Code: (Select All)
Screen _NewImage(1280, 720, 32)
$Color:32
PieSlice 100, 100, 100, 45, 0, Red
PieSlice 200, 200, 50, 270, 120, Green
PieSlice 300, 300, 50, 120, 270, Gold
Print Atan(100, 100, 171, 29) '45 degree coordinates
Print Atan(100, 100, 100, 150) '270 degree coordinates
Print Atan(100, 100, 75, 57) '120 degree coordinates
Function Atan (x1, y1, x2, y2)
Atan = (360 - _R2D(_Atan2(y2 - y1, x2 - x1))) Mod 360
End Function
Sub PieSlice (cx As Long, cy As Long, r As Long, startAngle As Long, endAngle As Long, c As _Unsigned Long)
Dim As Long x, y, x1, y1
If startAngle > endAngle Then endAngle = endAngle + 360
x1 = Sin(_D2R(startAngle + 90)) * r
y1 = Cos(_D2R(startAngle + 90)) * r
Line (cx, cy)-Step(x1, y1), c
For i = startAngle To endAngle Step Sgn(endAngle - startAngle)
x = Sin(_D2R(i + 90)) * r
y = Cos(_D2R(i + 90)) * r
Line -(cx + x, cy + y), c
If x <> x1 And y <> y1 And xt = 0 Then 'chose a point inside the arc to fill
xt = Sin(_D2R(i + 90)) * r / 2
yt = Cos(_D2R(i + 90)) * r / 2
End If
Next
Line -(cx, cy), c
Paint (cx + xt, cy + yt), c
End Sub
|