'draw_polyFT

' by James D.  Jarvis  , August 20,2023

'draw filled  polygons

'

'HEADER

Dim Shared xmax, ymax

xmax = 800: ymax = 500

Screen _NewImage(xmax, ymax, 32)

Dim Shared pk& 'must be included in a program that uses polyFT

pk& = _NewImage(3, 3, 32) 'must be included in a program that uses polyFT



'======================================

' demo

'======================================

' This demo draws 64000 random polygons, and then clears the screen and draws a handful of polygons  rotating



Randomize Timer



t1 = Timer

For reps = 1 To 64000

    polyFT Int(Rnd * xmax), Int(Rnd * ymax), Int(3 + Rnd * 20), Int(3 + Rnd * 12), Int(Rnd * 60), Int(1 + Rnd * 3), Int(1 + Rnd * 3), _RGB32(Int(Rnd * 256), Int(Rnd * 256), Int(Rnd * 256)), _RGB32(Int(Rnd * 256), Int(Rnd * 256), Int(Rnd * 256))

Next reps

t2 = Timer

Print "That took "; t2 - t1; " seconds to draw 64000 polygons"

Sleep

rtn = 0

Do

    _Limit 60

    Cls

    Print "Press <ESC> to quit>"

    polyFT 100, 100, 40, 3, rtn, 1, 1, _RGB32(100, 200, 50), 0

    polyFT 200, 100, 40, 4, 45 + rtn, 1, 1, _RGB32(100, 200, 250), 0

    polyFT 300, 100, 40, 5, rtn, 1, 1, _RGB32(200, 100, 250), 0

    polyFT 400, 100, 40, 6, rtn, 1, 1, _RGB32(100, 250, 150), 0

    polyFT 500, 100, 40, 7, rtn, 1, 1, _RGB32(150, 200, 200), 0

    polyFT 600, 100, 40, 8, 22.5 + rtn, 1, 1, _RGB32(200, 200, 0), 0

    _PrintString (100 - (_PrintWidth("Triangle")) / 2, 160), "Triangle"

    _PrintString (200 - (_PrintWidth("Square")) / 2, 160), "Square"

    _PrintString (300 - (_PrintWidth("Pentagon")) / 2, 160), "Pentagon"

    _PrintString (400 - (_PrintWidth("Hexagon")) / 2, 160), "Hexagon"

    _PrintString (500 - (_PrintWidth("Heptagon")) / 2, 160), "Heptagon"

    _PrintString (600 - (_PrintWidth("Octagon")) / 2, 160), "Octagon"

    rtn = rtn + 1: If rtn > 360 Then rtn = 0

    _Display 'for smooth display

Loop Until InKey$ = Chr$(27)



'==========================================================================

'subroutines

'

'  polyFT    draw a filled polygon

'

' setklr    is a sub to build the color image used by triangles in  polyFT

'====================================== ==================================

Sub polyFT (cx As Long, cy As Long, rad As Long, sides As Integer, rang As Long, ww, vv, klr As _Unsigned Long, lineyes As _Unsigned Long)

    'draw an equilateral polygon using filled triangle for each segment

    'centered at cx,cy to radius rad of sides # of face rotated to angle rang scaled to ww and vv of color klr and lineyes if there is an outline, a value 0 would create no outline

    setklr klr

    Dim px(sides)

    Dim py(sides)

    pang = 360 / sides

    ang = 0

    For p = 1 To sides

        px(p) = cx + (rad * Cos(0.01745329 * (ang + rang))) * ww

        py(p) = cy + (rad * Sin(0.01745329 * (ang + rang))) * vv

        ang = ang + pang



    Next p

    For p = 1 To sides - 1

        _MapTriangle (0, 0)-(0, 2)-(2, 0), pk& To(cx, cy)-(px(p), py(p))-(px(p + 1), py(p + 1))

        If lineyes > 0 Then Line (px(p), py(p))-(px(p + 1), py(p + 1)), lineyes

    Next p

    _MapTriangle (0, 0)-(0, 2)-(2, 0), pk& To(cx, cy)-(px(sides), py(sides))-(px(1), py(1))

    If lineyes > 0 Then Line (px(sides), py(sides))-(px(1), py(1)), lineyes







End Sub

Sub setklr (klr As Long)

    'internal routine to setup an image to copy a colored triangle from in the color klr

    'called by polyT

    _Dest pk&

    Line (0, 0)-(2, 2), klr, BF

    _Dest 0

End Sub