SmallBasic Turtle Logo Source Code 2

The bit about Show/Hide Turtle was very time consuming. I do wish Small Basic has better Screen Buffer capabilities.



Turtle Logo in Small Basic
'by Harry Hardjono
'Turtle angle speed x1 y1 x0 y0
'Turtle move moveto penup pendown
'Turtle turn turnleft turnright
'Turtle show hide
'
' I did this in one afternoon. Could've been faster if I ignore Show/Hide Turtle

GraphicsWindow.Show()
GraphicsWindow.Clear()


beginloop:
GraphicsWindow.Clear()
cmd1="init"
Toitle()
Program.Delay(2000)
cmd1="hide"
Toitle()

For loop=1 to 50
cmd1="penup"
Toitle()
cmd1="moveto"
cmd2=Math.GetRandomNumber(sx)
cmd3=Math.GetRandomNumber(sy)
Toitle()
cmd1="pendown"
Toitle()
cmd1="color"
cmd2=GraphicsWindow.GetRandomColor()
Toitle()
cmd1="size"
cmd2=Math.GetRandomNumber(10)
Toitle()
' Show Turtle is very slow!
' If (loop=10) Then
' cmd1="show"
' Toitle()
' ElseIf (loop=30) then
' cmd1="hide"
' Toitle()
' EndIf
For loop2=1 to Math.GetRandomNumber(6)
cmd1="turn"
cmd2=Math.GetRandomNumber(360)
Toitle()
cmd1="move"
cmd2=Math.GetRandomNumber(1000)
Toitle()
endfor
endfor
Program.Delay(5000)
Goto beginloop



Sub Toitle
'cmd1=command (input)
'cmd2=param1 (input)
'cmd3=param2 (input)
If (cmd1="init") then
sy=GraphicsWindow.Height
sx=GraphicsWindow.Width
'Bug: GetPixel does not take Background color
GraphicsWindow.BrushColor="white"
GraphicsWindow.FillRectangle(0,0,sx,sy)
x1=sx/2
y1=sy/2
x0=x1
y0=y1
p=1
angle=180
col="blue"
GraphicsWindow.BrushColor=col
siz=1
ts=1
SaveBG()
elseif (cmd1="penup") then
p=0
elseif (cmd1="pendown") then
p=1
elseif (cmd1="move") then
'forward
LoadBG()
x0=x1
y0=y1
x1=x0+cmd2*Math.Sin(Math.GetRadians(angle))
y1=y0+cmd2*Math.Cos(Math.GetRadians(angle))
draw()
SaveBG()
elseif (cmd1="moveto") then
LoadBG()
x0=x1
y0=y1
x1=cmd2
y1=cmd3
draw()
SaveBG()
elseif (cmd1="turn") then
LoadBG()
angle=cmd2
SaveBG()
elseif (cmd1="turnleft") then
LoadBG()
angle=angle+cmd2
SaveBG()
elseif (cmd1="turnright") then
LoadBG()
angle=angle-cmd2
SaveBG()
elseif (cmd1="color") then
col=cmd2
elseif (cmd1="size") then
siz=math.Max(1,cmd2)
siz=math.Min(10,siz)
elseif (cmd1="show") then
if (ts<>1) then
ts=1
SaveBG()
endif
elseif (cmd1="hide") then
LoadBG()
ts=0
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
' RemBugFix2()
'x1=Math.Remainder(x1,sx)
'y1=Math.Remainder(y1,sy)
'angle=Math.Remainder(angle,360)

If (ts=1) then
DrawTurtle()
endif

endsub

Sub DrawTurtle
tx1=x1+10*Math.Sin(Math.GetRadians(angle))
ty1=y1+10*Math.Cos(Math.GetRadians(angle))
tx2=x1+10*Math.Sin(Math.GetRadians(angle+140))
ty2=y1+10*Math.Cos(Math.GetRadians(angle+140))
tx3=x1+10*Math.Sin(Math.GetRadians(angle+220))
ty3=y1+10*Math.Cos(Math.GetRadians(angle+220))
GraphicsWindow.FillTriangle(tx1,ty1,tx2,ty2,tx3,ty3)
endsub


Sub RemBugFix
While (px<0) px=px+sx EndWhile While (py<0) py=py+sy EndWhile endsub Sub RemBugFix2 While (x1<0) x1=x1+sx EndWhile While (y1<0) y1=y1+sy EndWhile While (angle<0) angle=angle+360 EndWhile endsub 'Draw Sub Draw If (p>0) then
If (x0<>x1 or y0<>y1) then
m=math.Max(math.Abs(x1-x0),math.Abs(y1-y0))
mx1=0
mx3=m
For i=0 To m
my1=x0
my3=x1
mx2=i
map()
px=my2
my1=y0
my3=y1
mx2=i
map()
py=my2
RemBugFix()
px=Math.Remainder(px,sx)
py=Math.Remainder(py,sy)
If (siz>1) then
GraphicsWindow.BrushColor=col
GraphicsWindow.FillEllipse(px,py,siz,siz)
else
GraphicsWindow.SetPixel(px,py,col)
endif
EndFor
endif
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
RemBugFix2()
x1=Math.Remainder(x1,sx)
y1=Math.Remainder(y1,sy)
angle=Math.Remainder(angle,360)

endsub

'map function
Sub map
'x1-x2-x3 y1-y2-y3
'(x2-x1)/(x3-x1)=(y2-y1)/(y3-y1)
'(y3-y1)*(x2-x1)/(x3-x1)=(y2-y1)
'y1+(y3-y1)*(x2-x1)/(x3-x1)=y2
my2=((my3-my1)*(mx2-mx1)/(mx3-mx1))+my1
EndSub


sub SaveBG
If (ts=1) then
BGc=0
BGx1=Math.Floor(Math.Max(0,x1-10))
BGx1=Math.Floor(Math.Min(sx,BGx1))
BGy1=Math.Floor(Math.Max(0,y1-10))
BGy1=Math.Floor(Math.Min(sy,BGy1))
BGx2=Math.Floor(Math.Max(0,x1+10))
BGx2=Math.Floor(Math.Min(sx,BGx2))
BGy2=Math.Floor(Math.Max(0,y1+10))
BGy2=Math.Floor(Math.Min(sy,BGy2))
For BGy=BGy1 To BGy2
For BGx=BGx1 To BGx2
BGc=BGc+1
BG_Array[BGc]=GraphicsWindow.GetPixel(BGx,BGy)
EndFor
endfor
' TextWindow.Write("SaveBG ")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
endsub

Sub LoadBG
If (ts=1) then
BGc=0
For BGy=BGy1 To BGy2
For BGx=BGx1 To BGx2
BGc=BGc+1
GraphicsWindow.SetPixel(BGx,BGy,BG_Array[BGc])
EndFor
endfor
' TextWindow.Write("LoadBG")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
EndSub