Simple turtle graphics library

[Deleted]

This library was initially created to work with HUG, however, as it make more sense to use it with a new canvas.bac library, it's been slightly modified. It will not work with HUG any more and SETCOLOR function has been removed.


This is a BaCon version of a simple turtle graphics library I've written for Yabasic some time ago. Commands:

FORWARD (x) - moves the turtle x pixels forward and draws the line when pen is down
BACKWARD (x) - moves the turtle x pixels backward and draws the line when pen is down
TURNRIGHT (x) - turns the turtle x degrees to the right
TURNLEFT (x) - turns the turtle x degrees to the left
PENDOWN () - puts the pen down
PENUP () - lifts the pen up
GOXY (x, y) - moves the turtle to (x, y) position
GOX (x) - moves the turtle vertically by x pixels
GOY (x) - moves the turtle horizontally by x pixels
RESETANGLE () - set the angle to 0
SETCOLOR ("#xxxxxx") - set color for drawing (use INK from canvas.bac instead)

No matter if the pen is down or up, GOXY, GOX and GOY don't draw anything on the canvas. Value of angle (in degrees) is stored in katzolwia global variable. Position of the turtle is stored in pozycjax and pozycjay global variables.

Library:


GLOBAL KATZOLWIA, POZYCJAX, POZYCJAY, RYSOWANIE
GLOBAL KOLOR$

KOLOR$ = "#000000"
KATZOLWIA = 0
POZYCJAX = 300
POZYCJAY = 300
RYSOWANIE = 1

SUB FORWARD (NUMBER DLUGOSC)
LOCAL A, B, X, Y
A = INT (SIN (KATZOLWIA * PI / 180) * DLUGOSC)
B = INT (COS (KATZOLWIA * PI / 180) * DLUGOSC)
X = POZYCJAX + A
Y = POZYCJAY - B
IF RYSOWANIE = 1 THEN
LINE (KOLOR$, POZYCJAX, POZYCJAY, X, Y)
END IF
POZYCJAX = X
POZYCJAY = Y
SYNC ()
END SUB

SUB BACKWARD (NUMBER DLUGOSC)
LOCAL A, B, X, Y
A = INT (SIN (KATZOLWIA * PI / 180) * DLUGOSC)
B = INT (COS (KATZOLWIA * PI / 180) * DLUGOSC)
X = POZYCJAX - A
Y = POZYCJAY + B
IF RYSOWANIE = 1 THEN
LINE (KOLOR$, POZYCJAX, POZYCJAY, X, Y)
END IF
POZYCJAX = X
POZYCJAY = Y
SYNC ()
END SUB

SUB TURNRIGHT (NUMBER ZMIANA)
KATZOLWIA = KATZOLWIA + ZMIANA
IF KATZOLWIA > 360 THEN
KATZOLWIA = KATZOLWIA - 360
END IF
IF KATZOLWIA < 0 THEN
KATZOLWIA = KATZOLWIA + 360
END IF
END SUB

SUB TURNLEFT (NUMBER ZMIANA)
KATZOLWIA = KATZOLWIA - ZMIANA
IF KATZOLWIA > 360 THEN
KATZOLWIA = KATZOLWIA - 360
END IF
IF KATZOLWIA < 0 THEN
KATZOLWIA = KATZOLWIA + 360
END IF
END SUB

SUB PENUP
RYSOWANIE = 0
END SUB

SUB PENDOWN
RYSOWANIE = 1
END SUB

SUB GOXY (NUMBER ZMIANAX, NUMBER ZMIANAY)
POZYCJAX = ZMIANAX
POZYCJAY = ZMIANAY
END SUB

SUB GOX (NUMBER ZMIANAX)
POZYCJAX = POZYCJAX + ZMIANAX
END SUB

SUB GOY (NUMBER ZMIANAY)
POZYCJAY = POZYCJAY + ZMIANAY
END SUB

SUB RESETANGLE
KATZOLWIA = 0
END SUB

SUB SETCOLOR (STRING NOWYKOLOR$)
KOLOR$ = NOWYKOLOR$
END SUB


An example program:


INCLUDE "/usr/lib/bacon/hug.bac"

HUGOPTIONS ("CANVAS GL")
HUGOPTIONS ("GL_FREEZE 1")

INCLUDE "turtle.bac"

FUNCTION RYSUJ
SQUARE ("#0000FF", 0, 0, 900, 600, TRUE)
RESETANGLE ()
GOXY (110, 300)
FOR X = 1 TO 100
FORWARD (250)
TURNLEFT (198)
NEXT X

RESETANGLE ()
SETCOLOR ("#FF0000")
GOXY (230, 440)
FOR K = 1 TO 10
GOX (2)
GOY (2)
FOR X = 1 TO 36
IF MOD (X, 2) = 0 THEN
PENUP ()
END IF
BACKWARD (20)
PENDOWN ()
TURNRIGHT (10)
NEXT X
NEXT K

RESETANGLE ()
SETCOLOR ("@FFFF00")
GOXY (350, 550)
K = 2
WHILE (K < 496)
FORWARD (500 - K)
TURNRIGHT (91)
K = K + 2
C = C + 1
WEND
SYNC ()
RETURN (FALSE)
END FUNCTION

WIN = WINDOW ("Example of turtle graphics", 920, 620)
RYSUNEK = CANVAS (900, 600)
ATTACH (WIN, RYSUNEK, 10, 10)
TIMEOUT (50, RYSUJ)
DISPLAY


EDIT: Here is a slower version:

INCLUDE "/usr/lib/bacon/hug.bac"
INCLUDE "/usr/lib/bacon/turtle.bac"

HUGOPTIONS ("CANVAS GL")
HUGOPTIONS ("GL_FREEZE 1")

FUNCTION RYSUJ
SQUARE ("#0000FF", 0, 0, 900, 600, TRUE)
RESETANGLE ()
GOXY (110, 300)
FOR X = 1 TO 20
FORWARD (250)
TURNLEFT (198)
SLEEP (500)
NEXT X

RESETANGLE ()
SETCOLOR ("#FF0000")
GOXY (230, 440)
FOR K = 1 TO 10
GOX (2)
GOY (2)
FOR X = 1 TO 36
IF MOD (X, 2) = 0 THEN
PENUP ()
END IF
BACKWARD (20)
PENDOWN ()
TURNRIGHT (10)
SLEEP (100)
NEXT X
NEXT K

RESETANGLE ()
SETCOLOR ("#FFFF00")
GOXY (350, 550)
K = 2
WHILE (K < 496)
FORWARD (500 - K)
TURNRIGHT (91)
K = K + 2
C = C + 1
SLEEP (250)
WEND
RETURN (FALSE)
END FUNCTION

WIN = WINDOW ("Example of turtle graphics", 920, 620)
RYSUNEK = CANVAS (900, 600)
ATTACH (WIN, RYSUNEK, 10, 10)
TIMEOUT (50, RYSUJ)
DISPLAY


Sources are attached.

EDIT 2: I've changed commands to capitals in description (thanx alexfish!)

Attachments:

[Pjot]

Hi Tomaaz,

We like your concept of Turtle graphics a lot!

Would you mind if I would incorporate your ideas into the canvas context (of course with the accompanying credits to you)?

Regards
Peter

[vovchik]

Dear all,

Here are a few more demos using canvas and turtle. Thanks, Tomaaz, for explaining how to get back the current the cursor position. It had excaped me. We can start writing some nice and complex turtle routines!

With kind regards,
vovchik

UPDATE: Forgot torus source in the archive - just added it and upoaded a new archive.

Attachments:

[Deleted]

Oct 4, 2015 6:48:09 GMT 1 Pjot said:

Hi Tomaaz,
Would you mind if I would incorporate your ideas into the canvas context (of course with the accompanying credits to you)?

Not at all. Please, use it the way you want. I've already modified it so it works with canvas.bac (check the first post in this topic), but was "smart" enough to forget to upload it. So, here it is:


GLOBAL KATZOLWIA, POZYCJAX, POZYCJAY, RYSOWANIE

KATZOLWIA = 0
POZYCJAX = 300
POZYCJAY = 300
RYSOWANIE = 1

SUB FORWARD (NUMBER DLUGOSC)
LOCAL A, B, X, Y
A = INT (SIN (KATZOLWIA * PI / 180) * DLUGOSC)
B = INT (COS (KATZOLWIA * PI / 180) * DLUGOSC)
X = POZYCJAX + A
Y = POZYCJAY - B
IF RYSOWANIE = 1 THEN
LINE (POZYCJAX, POZYCJAY, X, Y)
END IF
POZYCJAX = X
POZYCJAY = Y
SYNC ()
END SUB

SUB BACKWARD (NUMBER DLUGOSC)
LOCAL A, B, X, Y
A = INT (SIN (KATZOLWIA * PI / 180) * DLUGOSC)
B = INT (COS (KATZOLWIA * PI / 180) * DLUGOSC)
X = POZYCJAX - A
Y = POZYCJAY + B
IF RYSOWANIE = 1 THEN
LINE (POZYCJAX, POZYCJAY, X, Y)
END IF
POZYCJAX = X
POZYCJAY = Y
SYNC ()
END SUB

SUB TURNRIGHT (NUMBER ZMIANA)
KATZOLWIA = KATZOLWIA + ZMIANA
IF KATZOLWIA > 360 THEN
KATZOLWIA = KATZOLWIA - 360
END IF
IF KATZOLWIA < 0 THEN
KATZOLWIA = KATZOLWIA + 360
END IF
END SUB

SUB TURNLEFT (NUMBER ZMIANA)
KATZOLWIA = KATZOLWIA - ZMIANA
IF KATZOLWIA > 360 THEN
KATZOLWIA = KATZOLWIA - 360
END IF
IF KATZOLWIA < 0 THEN
KATZOLWIA = KATZOLWIA + 360
END IF
END SUB

SUB PENUP
RYSOWANIE = 0
END SUB

SUB PENDOWN
RYSOWANIE = 1
END SUB

SUB GOXY (NUMBER ZMIANAX, NUMBER ZMIANAY)
POZYCJAX = ZMIANAX
POZYCJAY = ZMIANAY
END SUB

SUB GOX (NUMBER ZMIANAX)
POZYCJAX = POZYCJAX + ZMIANAX
END SUB

SUB GOY (NUMBER ZMIANAY)
POZYCJAY = POZYCJAY + ZMIANAY
END SUB

SUB RESETANGLE
KATZOLWIA = 0
END SUB


To use Turtle with HUG use the old version.


turtleHUG.zip (1.16 KB)
turtle.bac.zip (512 B)

[Pjot]

Thanks Tomaaz!

I have added the API with credits to you, but I slightly changed the implementation. The new canvas 2.0 can be found in the beta directory.

• PENDOWN, PENUP, TURNRIGHT, TURNLEFT, RESETANGLE were taken in the same way from your API
  
• PENXY instead of GOXY seemed to be less confusing with the existing GOTO and GOTOXY from BaCon
• DRAW instead of FORWARD/BACKWARD. For BACKWARD, just use a negative number in DRAW()
• PENTYPE to define the kind of drawing, 0=line and 1=arc

Please anybody 'shoot' at the latest changes, all is open to improvement Small demo program below.

Furthermore I changed CIRCLE and SQUARE so they use radius as 3rd and 4th argument, this seemed to make more sense in case of creating ellipses or rectangles.

Thanks again Tomaaz!
Peter

INCLUDE canvas.bac

WINDOW("Turtle test", 640, 480)

TEXT("Turtle uses arcs", 50, 50)
PENXY(100, 100)
PENTYPE(1)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
INK(100,255,100,255)
PAINT(120, 120)

INK(0,0,0,255)
TEXT("Turtle uses lines", 300, 50)
PENXY(350, 100)
RESETANGLE
PENTYPE(0)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
TURNRIGHT(45)
DRAW(60)
INK(255,80,100,255)
PAINT(320, 200)

INK(0,0,0,255)
TEXT("We don't need BACKWARD to draw, just use a negative argument in DRAW()", 10, 360)
PEN(2,0)
PENXY(150, 400)
RESETANGLE
DRAW(100)
PENXY(150, 400)
INK(0,0,255,255)
DRAW(-100)

WAITKEY


Attachments:

[vovchik]

Dear Peter,

Nice and thanks. I don't see the effect of PAINT - everything is black and white for me. I will look at the PAIN routine and see whether I can figure it out...unless you have done that already.

With kind regards,
vovchik

[Pjot]

All,

Ported some programs already:

- Aquarium
- Straw Flower
- Torus

@ vovchik: paint seems to work for me, not sure what is going wrong?

BR
Peter

EDIT: more programs can be found in the beta directory.

[vovchik]

Dear all,

Here is some nice broccoli: broccoli

With kind regards,
vovchik

Attachments:

broccoli.tar.gz (7.47 KB)

[Pjot]

Hi vovchik,

Very nice! Works without problems. It is typically the kind of demo for which the canvas was created.

Thanks!

Peter

[Pjot]

Code taken from here.

'Sir Real.bas for SmallBASIC 2015-09-29 MGA/B+
'translated and modified from Peter's "surrealism" BP.org post
'ported to BaCon 6/10/2015 by PvE

INCLUDE canvas.bac

DECLARE x, y, var, r, theta TYPE float

ScrW=320:ScrH=320
WINDOW("Surrealism", ScrW, ScrH)

FOR mx=0 TO 8 STEP 4 :'get Real
x =-8
FOR i=0 TO ScrW
y=-8
FOR j=0 TO ScrH
r=SQR((x*x)+(y*y))       :'extra () to SQR whole expression
theta = ATN(y/x)         :'different atan
IF x>0 THEN theta=-theta :'this seems needed for atan and for odd multipliers to theta
var = SIN(mx*cos(r)+5*theta)
INK((var+1)*127,0,0,255)
PIXEL(i,j)
INCR y, .05
NEXT
INCR x, .05
NEXT
NEXT

WAITKEY


Attachments:

[vovchik]

Dear Peter,

It looks great and the code is tiny. Thanks.

With kind regards,
vovchik