CloudFlare suffered a massive security issue affecting all of its customers, including Rosetta Code. All passwords not changed since February 19th 2017 have been expired, and session cookie longevity will be reduced until late March.--Michael Mol (talk) 05:15, 25 February 2017 (UTC)

Polyspiral

From Rosetta Code
Task
Polyspiral
You are encouraged to solve this task according to the task description, using any language you may know.

A Polyspiral is a spiral made of multiple line segments, whereby each segment is larger (or smaller) than the previous one by a given amount. Each segment also changes direction at a given angle.


Task

Animate a series of polyspirals, by drawing a complete spiral then incrementing the angle, and (after clearing the background) drawing the next, and so on. Every spiral will be a frame of the animation. The animation may stop as it goes full circle or continue indefinitely. The given input values may be varied.

If animation is not practical in your programming environment, you may show a single frame instead.


Pseudo code
    set incr to 0.0

    // animation loop
    WHILE true 

        incr = (incr + 0.05) MOD 360
        x = width / 2
        y = height / 2
        length = 5
        angle = incr

        // spiral loop
        FOR 1 TO 150
            drawline
            change direction by angle
            length = length + 3
            angle = (angle + incr) MOD 360
        ENDFOR
    



C++[edit]

This Windows programm has no animation, it will simply save 100 bitmaps onto your harddrive

 
#include <windows.h>
#include <sstream>
#include <ctime>
 
const float PI = 3.1415926536f, TWO_PI = 2.f * PI;
class vector2
{
public:
vector2( float a = 0, float b = 0 ) { set( a, b ); }
void set( float a, float b ) { x = a; y = b; }
void rotate( float r ) {
float _x = x, _y = y,
s = sinf( r ), c = cosf( r ),
a = _x * c - _y * s, b = _x * s + _y * c;
x = a; y = b;
}
vector2 add( const vector2& v ) {
x += v.x; y += v.y;
return *this;
}
float x, y;
};
class myBitmap
{
public:
myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {}
~myBitmap(){
DeleteObject( pen );
DeleteObject( brush );
DeleteDC( hdc );
DeleteObject( bmp );
}
bool create( int w, int h ){
BITMAPINFO bi;
ZeroMemory( &bi, sizeof( bi ) );
bi.bmiHeader.biSize = sizeof( bi.bmiHeader );
bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
bi.bmiHeader.biCompression = BI_RGB;
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biWidth = w;
bi.bmiHeader.biHeight = -h;
 
HDC dc = GetDC( GetConsoleWindow() );
bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 );
if( !bmp ) return false;
 
hdc = CreateCompatibleDC( dc );
SelectObject( hdc, bmp );
ReleaseDC( GetConsoleWindow(), dc );
 
width = w; height = h;
return true;
}
void clear( BYTE clr = 0 ){
memset( pBits, clr, width * height * sizeof( DWORD ) );
}
void setBrushColor( DWORD bClr ){
if( brush ) DeleteObject( brush );
brush = CreateSolidBrush( bClr );
SelectObject( hdc, brush );
}
void setPenColor( DWORD c ){
clr = c; createPen();
}
void setPenWidth( int w ){
wid = w; createPen();
}
void saveBitmap( std::string path ){
BITMAPFILEHEADER fileheader;
BITMAPINFO infoheader;
BITMAP bitmap;
DWORD wb;
 
GetObject( bmp, sizeof( bitmap ), &bitmap );
DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight];
ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) );
ZeroMemory( &infoheader, sizeof( BITMAPINFO ) );
ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) );
 
infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
infoheader.bmiHeader.biCompression = BI_RGB;
infoheader.bmiHeader.biPlanes = 1;
infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader );
infoheader.bmiHeader.biHeight = bitmap.bmHeight;
infoheader.bmiHeader.biWidth = bitmap.bmWidth;
infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD );
 
fileheader.bfType = 0x4D42;
fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER );
fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage;
 
GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS );
 
HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL );
WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL );
WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL );
WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL );
CloseHandle( file );
 
delete [] dwpBits;
}
HDC getDC() const { return hdc; }
int getWidth() const { return width; }
int getHeight() const { return height; }
private:
void createPen(){
if( pen ) DeleteObject( pen );
pen = CreatePen( PS_SOLID, wid, clr );
SelectObject( hdc, pen );
}
HBITMAP bmp; HDC hdc;
HPEN pen; HBRUSH brush;
void *pBits; int width, height, wid;
DWORD clr;
};
int main( int argc, char* argv[] ) {
srand( unsigned( time( 0 ) ) );
myBitmap bmp;
bmp.create( 600, 600 ); bmp.clear();
HDC dc = bmp.getDC();
float fs = ( TWO_PI ) / 100.f;
int index = 0;
std::string a = "f://users//images//test", b;
float ang, len;
vector2 p1, p2;
 
for( float step = 0.1f; step < 5.1f; step += .05f ) {
ang = 0; len = 2;
p1.set( 300, 300 );
bmp.setPenColor( RGB( rand() % 50 + 200, rand() % 300 + 220, rand() % 50 + 200 ) );
for( float xx = 0; xx < TWO_PI; xx += fs ) {
MoveToEx( dc, (int)p1.x, (int)p1.y, NULL );
p2.set( 0, len ); p2.rotate( ang ); p2.add( p1 );
LineTo( dc, (int)p2.x, (int)p2.y );
p1 = p2; ang += step; len += step;
}
std::ostringstream ss; ss << index++;
b = a + ss.str() + ".bmp";
bmp.saveBitmap( b );
bmp.clear();
}
return 0;
}
 

Gnuplot[edit]

Works with: gnuplot version 5.0 (patchlevel 3) and above

Plotting a polyspiral file-function for the load command[edit]

plotpoly.gp file for the load command is the only possible imitation of the fine function in the gnuplot.

 
## plotpoly.gp 1/10/17 aev
## Plotting a polyspiral and writing to the png-file.
## Note: assign variables: rng, d, clr, filename and ttl (before using load command).
## Direction d (-1 clockwise / 1 counter-clockwise)
reset
set terminal png font arial 12 size 640,640
ofn=filename.".png"
set output ofn
unset border; unset xtics; unset ytics; unset key;
set title ttl font "Arial:Bold,12"
set parametric
c=rng*pi; set xrange[-c:c]; set yrange[-c:c];
set dummy t
plot [0:c] t*cos(d*t), t*sin(d*t) lt rgb @clr
set output
 

Plotting many versions of a polyspiral.[edit]

Note: only 6 versions have pictures here on RC.

File:PS0gp.png
Output PS0gp.png
File:PS1gp.png
Output PS1gp.png
File:PS3gp.png
Output PS3gp.png
File:PS4gp.png
Output PS4gp.png
File:PS5gp.png
Output PS5gp.png
File:PS6gp.png
Output PS6gp.png
 
## PSpirals.gp 1/10/17 aev
## Plotting many polyspiral pictures.
## Note: assign variables: rng, d, clr, filename and ttl (before using load command).
## Direction d (-1 clockwise / 1 counter-clockwise)
#cd 'C:\gnupData'
 
##PS0 smooth spiral (not a polyspiral)
reset
set terminal png font arial 12 size 640,640
set output "PS0gp.png"
set title "Smooth spiral #0 rng=10" font "Arial:Bold,12"
set parametric
c=10*pi; set trange [0:c]; set xrange[-c:c]; set yrange[-c:c];
set samples 1000
plot t*cos(t), t*sin(t) lt rgb "red"
set output
 
##PS1 A polyspiral (Same size as PS0).
rng=10; d=1; clr = '"dark-green"';
filename = "PS1gp"; ttl = "Polyspiral #1 rng=10";
load "plotpoly.gp"
 
##PS3 A polyspiral
rng=20; d=-1; clr = '"red"';
filename = "PS3gp"; ttl = "Polyspiral #3 rng=20";
load "plotpoly.gp"
 
##PS4 A polyspiral having 4 secondary spirals.
rng=50; d=-1; clr = '"navy"';
filename = "PS4gp"; ttl = "Polyspiral #4 rng=50";
load "plotpoly.gp"
 
##PS5 Not a polyspiral, but has 8 secondary spirals.
rng=75; d=-1; clr = '"navy"';
filename = "PS5gp"; ttl = "Polyspiral #5 rng=75";
load "plotpoly.gp"
 
##PS6 Not a polyspiral, just a nice figure (seen in zkl).
rng=100; d=-1; clr = '"navy"';
filename = "PS6gp"; ttl = "Polyspiral #6 rng=100";
load "plotpoly.gp"
 
##==============================
#### NO PICTURES on RC starting from here, test it yourself
 
##PS2 A polyspiral
rng=20; d=1; clr = '"red"';
filename = "PS2gp"; ttl = "Polyspiral #2 rng=20";
load "plotpoly.gp"
 
##PS7 Looks like PS5, but has 5 secondary spirals (not 8)
rng=120; d=-1; clr = '"green"';
filename = "PS7gp"; ttl = "Polyspiral #7 rng=120";
load "plotpoly.gp"
 
##PS8 Looks like PS4, but more distortion.
rng=150; d=-1; clr = '"green"';
filename = "PS8gp"; ttl = "Polyspiral #8 rng=150";
load "plotpoly.gp"
 
##PS9 Looks like PS2, but less loops..
rng=175; d=-1; clr = '"green"';
filename = "PS9gp"; ttl = "Polyspiral #9 rng=175";
load "plotpoly.gp"
 
##PS10 One loop of a spiral
rng=200; d=-1; clr = '"green"';
filename = "PS10gp"; ttl = "Polyspiral #10 rng=200";
load "plotpoly.gp"
 
##PS11 Polyspiral with line segments crossing other line segments.
rng=30; d=-1; clr = '"navy"';
filename = "PS11gp"; ttl = "Polyspiral #11 rng=30";
load "plotpoly.gp"
 
##PS12 Looks like PS4, but has 5 secondary spirals.
rng=40; d=-1; clr = '"navy"';
filename = "PS12gp"; ttl = "Polyspiral #12 rng=40";
load "plotpoly.gp"
 
##PS13 Looks like PS5, but has 8 secondary spirals.
rng=60; d=-1; clr = '"navy"';
filename = "PS13gp"; ttl = "Polyspiral #13 rng=60";
load "plotpoly.gp"
 
##PS14 Looks like PS4, but has 5 secondary spirals.
rng=80; d=-1; clr = '"navy"'
filename = "PS14gp"; ttl = "Polyspiral #14 rng=80";
load "plotpoly.gp"
 
##PS15 Not a polyspiral. Hmmm, just a star?
rng=90; d=-1; clr = '"navy"';
filename = "PS15gp"; ttl = "Polyspiral #15 rng=90";
load "plotpoly.gp"
 
##PS16 Not a polyspiral. Hmmm, just another star?
rng=300; d=-1; clr = '"navy"';
filename = "PS16gp"; ttl = "Polyspiral #16 rng=300";
load "plotpoly.gp"
 
## Continue plotting starting with a range rng=110 to 400+ step 10 to discover new figures.
## END ##
 
Output:
1. All PSpirals.gp file commands.
2. First 6 plotted png-files: PS0gp.png - PS6gp.

Plotting a polyspiral file-function for the load command (for animation)[edit]

plotpolya.gp file for the load command is the only possible imitation of the fine function in the gnuplot.

 
## plotpolya.gp 1/19/17 aev
## Plotting a polyspiral and writing to the png-file. Simple plot for animation.
## Note: assign variables: rng, d, clr, filename (before using load command).
## ==== NO ttl (title) in this version.
reset
set terminal png font arial 12 size 640,640
ofn=filename.".png"
set output ofn
unset border; unset xtics; unset ytics; unset key;
set parametric
c=rng*pi; set xrange[-c:c]; set yrange[-c:c];
set dummy t
plot [0:c] t*cos(d*t), t*sin(d*t) lt rgb @clr
set output
 

Plotting many polyspiral and other pictures for animation.[edit]

Note: No generated pictures here on RC.

 
## PSpirals4a.gp 1/19/17 aev
## Plotting many polyspiral and other pictures for animation
## Notes: 1. Assign variables: rng, d, clr, filename(before using load command).
## ====== 2. NO title in this version.
## 3. Primarily range is changed.
## Direction d (-1 clockwise / 1 counter-clockwise)
#cd 'C:\gnupData'
 
##====== for PolySpirsAnim.gif ==========================================
##PS0 A polyspiral (direction: counter-clockwise).
rng=10; d=1; clr = '"red"'; filename = "PS0"; load "plotpolya.gp";
 
##PS1 A polyspiral (direction: clockwise).
rng=20; d=-1; clr = '"red"'; filename = "PS1"; load "plotpolya.gp";
 
##PS2 A polyspiral. Looks like PS1, but less loops..
rng=175; d=-1; clr = '"red"'; filename = "PS2"; load "plotpolya.gp";
 
##PS3 Polyspiral with line segments crossing other line segments.
rng=30; d=-1; clr = '"red"'; filename = "PS3"; load "plotpolya.gp";
 
##PS4 A polyspiral having 4 secondary spirals.
rng=50; d=-1; clr = '"red"'; filename = "PS4"; load "plotpolya.gp";
 
##PS5 A polyspiral. Looks like PS4, but has 5 secondary spirals.
rng=40; d=-1; clr = '"red"'; filename = "PS5"; load "plotpolya.gp";
 
##PS6 A polyspiral. Looks like PS4, but has more distortion.
rng=150; d=-1; clr = '"red"'; filename = "PS6"; load "plotpolya.gp";
 
##PS7 A polyspiral. Has 8 secondary spirals and even more distortion.
rng=60; d=-1; clr = '"red"'; filename = "PS7"; load "plotpolya.gp";
 
 
##====== for NiceFigsAnim.gif ==========================================
##PS8 Not a polyspiral, but has 8 secondary spirals.
rng=75; d=-1; clr = '"navy"'; filename = "PS8"; load "plotpolya.gp";
 
##PS9 Looks like PS8, but has 5 secondary spirals.
rng=80; d=-1; clr = '"navy"'; filename = "PS9"; load "plotpolya.gp";
 
##PS10 Looks like PS8, but has 5 secondary spirals (not 8)
rng=120; d=-1; clr = '"navy"'; filename = "PS10"; load "plotpolya.gp";
 
##PS11 Not a polyspiral, just nice figure.
rng=100; d=-1; clr = '"navy"'; filename = "PS11"; load "plotpolya.gp";
 
##PS12 Not a polyspiral. Hmmm, just a star?
rng=90; d=-1; clr = '"navy"'; filename = "PS12"; load "plotpolya.gp";
 
##PS13 Not a polyspiral. Hmmm, just another star?
rng=300; d=-1; clr = '"navy"'; filename = "PS13"; load "plotpolya.gp";
 
##PS14 Not a polyspiral, but has many short secondary spirals.
rng=700; d=-1; clr = '"navy"'; filename = "PS14"; load "plotpolya.gp";
 
Output:
1. All PSpirals4a.gp file commands.
2. 15 plotted png-files: PS0.png - PS14.png.

Creating 2 animated gif-files.[edit]

Note: No gif-files. File upload still not allowed. So, test it yourself.

File:PolySpirsAnim.gif
Output PolySpirsAnim.gif
File:NiceFigsAnim.gif
Output NiceFigsAnim.gif
 
## Animation for polyspirals PS0 - PS6
reset
set terminal gif animate delay 100 loop 2 size 640,640
set output 'PolySpirsAnim.gif'
unset border; unset xtics; unset ytics; unset key;
unset autoscale
set xrange[0:640]
set yrange[0:640]
do for [i=0:6]{plot 'PS'.i.'.png' binary filetype=png with rgbimage}
set output
 
## Animation for nice figures PS8 - PS14
reset
set terminal gif animate delay 100 loop 2 size 640,640
set output 'NiceFigsAnim.gif'
unset border; unset xtics; unset ytics; unset key;
unset autoscale
set xrange[0:640]
set yrange[0:640]
do for [i=8:14]{plot 'PS'.i.'.png' binary filetype=png with rgbimage}
set output
 
Output:
2 created gif-files: PolySpirsAnim.gif and NiceFigsAnim.gif

Showing 2 animated gif-files.[edit]

Create 2 the following html-files and envoke them in browser.

 
<!-- PolySpirsAnim.html -->
<html><body>
<h3>Gnuplot: Polyspirals animation >>
<a href="NiceFigsAnim.html">Next: Nice figures animation</a></h3>
<img src="PolySpirsAnim.gif">
</body></html>
 
 
<!-- NiceFigsAnim.html -->
<html><body>
<h3>Gnuplot: Nice figures animation >>
<a href="PolySpirsAnim.html">Next: Polyspirals animation</a></h3>
<img src="NiceFigsAnim.gif">
</body></html>
 
Output:
2 pages with animation.

J[edit]

J-polyspiral.gif
Translation of: java
require 'gl2 trig media/imagekit'
coinsert 'jgl2'
 
DT =: %30 NB. seconds
ANGLE =: 0.025p1 NB. radians
DIRECTION=: 0 NB. radians
 
POLY=: noun define
pc poly;pn "Poly Spiral";
minwh 320 320; cc isi isigraph;
)
 
poly_run=: verb define
wd POLY,'pshow'
wd 'timer ',":DT * 1000
)
 
poly_close=: verb define
wd 'timer 0; pclose'
)
 
sys_timer_z_=: verb define
recalcAngle_base_ ''
wd 'psel poly; set isi invalid'
)
 
poly_isi_paint=: verb define
drawPolyspiral DIRECTION
)
 
recalcAngle=: verb define
DIRECTION=: 2p1 | DIRECTION + ANGLE
)
 
drawPolyspiral=: verb define
glclear''
x1y1 =. (glqwh'')%2
a=. -DIRECTION
len=. 5
for_i. i.150 do.
glpen glrgb Hue a % 2p1
x2y2=. x1y1 + len*(cos,sin) a
gllines <.x1y1,x2y2
x1y1=. x2y2
len=. len+3
a=. 2p1 | a - DIRECTION
end.
)
 
poly_run''

Note that we're using a lot of wd commands here. You'll need to be running jqt for this to work.

Java[edit]

Polyspiral java2.png
Works with: Java version 8
import java.awt.*;
import java.awt.event.ActionEvent;
import javax.swing.*;
 
public class PolySpiral extends JPanel {
double inc = 0;
 
public PolySpiral() {
setPreferredSize(new Dimension(640, 640));
setBackground(Color.white);
 
new Timer(40, (ActionEvent e) -> {
inc = (inc + 0.05) % 360;
repaint();
}).start();
}
 
void drawSpiral(Graphics2D g, int len, double angleIncrement) {
 
double x1 = getWidth() / 2;
double y1 = getHeight() / 2;
double angle = angleIncrement;
 
for (int i = 0; i < 150; i++) {
 
g.setColor(Color.getHSBColor(i / 150f, 1.0f, 1.0f));
 
double x2 = x1 + Math.cos(angle) * len;
double y2 = y1 - Math.sin(angle) * len;
g.drawLine((int) x1, (int) y1, (int) x2, (int) y2);
x1 = x2;
y1 = y2;
 
len += 3;
 
angle = (angle + angleIncrement) % (Math.PI * 2);
}
}
 
@Override
public void paintComponent(Graphics gg) {
super.paintComponent(gg);
Graphics2D g = (Graphics2D) gg;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
 
drawSpiral(g, 5, Math.toRadians(inc));
}
 
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setTitle("PolySpiral");
f.setResizable(true);
f.add(new PolySpiral(), BorderLayout.CENTER);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}

Kotlin[edit]

Translation of: Java
// version 1.1.0
 
import java.awt.*
import java.awt.event.ActionEvent
import javax.swing.*
 
class PolySpiral() : JPanel() {
private var inc = 0.0
 
init {
preferredSize = Dimension(640, 640)
background = Color.white
Timer(40) {
inc = (inc + 0.05) % 360.0
repaint()
}.start()
}
 
private fun drawSpiral(g: Graphics2D, length: Int, angleIncrement: Double) {
var x1 = width / 2.0
var y1 = height / 2.0
var len = length
var angle = angleIncrement
for (i in 0 until 150) {
g.setColor(Color.getHSBColor(i / 150f, 1.0f, 1.0f))
val x2 = x1 + Math.cos(angle) * len
val y2 = y1 - Math.sin(angle) * len
g.drawLine(x1.toInt(), y1.toInt(), x2.toInt(), y2.toInt())
x1 = x2
y1 = y2
len += 3
angle = (angle + angleIncrement) % (Math.PI * 2.0)
}
}
 
override protected fun paintComponent(gg: Graphics) {
super.paintComponent(gg)
val g = gg as Graphics2D
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)
drawSpiral(g, 5, Math.toRadians(inc))
}
}
 
fun main(args: Array<String>) {
SwingUtilities.invokeLater {
val f = JFrame()
f.defaultCloseOperation = JFrame.EXIT_ON_CLOSE
f.title = "PolySpiral"
f.setResizable(true)
f.add(PolySpiral(), BorderLayout.CENTER)
f.pack()
f.setLocationRelativeTo(null)
f.setVisible(true)
}
}

Lua[edit]

Library: LÖVE

LÖVE defaults to animating at sixty frames per second, so the patterns become very complex very quickly.

function love.load ()
love.window.setTitle("Polyspiral")
incr = 0
end
 
function love.update (dt)
incr = (incr + 0.05) % 360
x1 = love.graphics.getWidth() / 2
y1 = love.graphics.getHeight() / 2
length = 5
angle = incr
end
 
function love.draw ()
for i = 1, 150 do
x2 = x1 + math.cos(angle) * length
y2 = y1 + math.sin(angle) * length
love.graphics.line(x1, y1, x2, y2)
x1, y1 = x2, y2
length = length + 3
angle = (angle + incr) % 360
end
end

Love2dPolyspiral.jpg

PARI/GP[edit]

Works with: PARI/GP version 2.7.4 and above

Plotting helper functions[edit]

Both versions #1 and #2 are based on using my own small plotting helper functions. You can find a few others on OEIS Wiki and here on RC Wiki.

 
\\ Plot the line from x1,y1 to x2,y2.
plotline(x1,y1,x2,y2,w=0)={plotmove(w, x1,y1);plotrline(w,x2-x1,y2-y1);}
\\ Convert degrees to radians.
rad2(degs)={return(degs*Pi/180.0)}
\\ Convert Polar coordinates to Cartesian.
cartes2(r,a,rndf=0)={my(v,x,y); x=r*cos(a); y=r*sin(a);
if(rndf==0, return([x,y]), return(round([x,y])))}
 

Version #1. Polyspiral (a spiral made of multiple line segments).[edit]

In this version function plotpspiral() was translated from Java and J. Some tweaks and options were added to make it reusable and outputting differently looking polyspirals. There are no animation features in PARI/GP.

Output Polyspiral1.png
Output Polyspiral2.png
Output Polyspiral3.png
Output Polyspiral3b.png
Output Polyspiral4.png
 
\\Polyspiral (a spiral made of multiple line segments)
\\ 4/15/16 aev
plotpspiral(size,lim,ai,d,di,c)={
my(x1,y1,x2,y2,air=ai*Pi,a,sai=Strprintf("%.3f",ai));
print(" *** Polyspiral, size=",size," lim=",lim," ai=",sai," d=",d," di=",di);
x1=0; y1=0;
a=air;
for(i=0, lim,
if(c==0, x2=x1+cos(a)*d; y2=y1-sin(a)*d,
x2=x1-sin(a)*d; y2=y1+cos(a)*d;);
plotline(x1,y1,x2,y2);
x1=x2; y1=y2; d+=di; a+=air;
);\\fend i
}
 
\\ Polyspiral() - Where: ai is an angle increment (in radians), d is a distance/length,
\\ c is a direction 0/1 (clockwise/counter-clockwise); other parameters are self explanative.
\\ 4/15/16 aev Last updated: 4/18/16
polyspiral(size,lim,ai,d,di,c=0)={
plotinit(0);
plotcolor(0,3); \\blue
plotscale(0, -size,size, -size,size);
plotmove(0, 0,0);
plotpspiral(size,lim,ai,d,di,c);
plotdraw([0,size,size]);
}
 
{\\ Executing:
polyspiral(1500,1500,0.25,9,5); \\Polyspiral1.png
polyspiral(1500,1500,0.25,3,2); \\Polyspiral2.png
polyspiral(10000,10000,0.03,3,2); \\Polyspiral3.png
polyspiral(10000,10000,0.03,3,2,1); \\Polyspiral3b.png
polyspiral(100000,100000,0.03,3,2);\\Polyspiral4.png
}
 
Output:

> polyspiral(1500,1500,0.25,9,5);  \\Polyspiral1.png
*** Polyspiral, size=1500 lim=1500 ai=0.250 d=9 di=5
 
> polyspiral(1500,1500,0.25,3,2);  \\Polyspiral2.png
*** Polyspiral, size=1500 lim=1500 ai=0.250 d=3 di=2
 
> polyspiral(10000,10000,0.03,3,2);  \\Polyspiral3.png
*** Polyspiral, size=100000 lim=100000 ai=0.030 d=3 di=2

> polyspiral(10000,10000,0.03,3,2,1);  \\Polyspiral3b.png
*** Polyspiral, size=100000 lim=100000 ai=0.030 d=3 di=2

> polyspiral(100000,100000,0.03,3,2);  \\Polyspiral4.png
*** Polyspiral, size=100000 lim=100000 ai=0.030 d=3 di=2

Version #2. Multi-spiral figure translated from zkl.[edit]

This is definitely not a polyspiral, but a very nice "multi-spiral" figure similar to shown in zkl and in a few other languages. Also, there is a very nice and impressive animation created in zkl, but not possible in PARI/GP.

Translation of: zkl
Output Spiralz.png
 
\\ plotpspiralz() Multi-spiral figure translated from zkl using my own ploting functions.
\\ 4/15/16 aev
plotpspiralz(size,lim,ai,di,lim2)={
my(x1,y1,u1,v1,air=rad2(ai),a,sai=Strprintf("%.3f",ai),sdi=Strprintf("%.3f",di),
sz2=size\2,aj,inc,ao,x,y,u,v,vc,r2i=rad2(130.0),d=0.0);
print(" *** Spiralz: size=",size," lim=",lim," ai=",sai," di=",sdi," lim2=",lim2);
x1=0; y1=0; u1=0; v1=0;
for(i=1, lim,
r=0.0; a=0.0;ao=0.0;
if(i>1, inc=air+r2i, inc=air);
for(j=1, lim2,
d=r+di; aj=a+inc;
vc=cartes2(r,a); x=vc[1]; y=vc[2];
vc=cartes2(r,aj); u=vc[1]; v=vc[2];
plotline(ao+x,ao+y,ao+u,ao+v);
r=d; a=aj;
);\\fend j
air+=0.05;
);\\fend i
}
 
\\ Spiralz() - Where: ai is an angle increment (in radians), di is a distance/length
\\ increment, other parameters are self explanative.
\\ 4/15/16 aev
Spiralz(size,lim,ai,di,lim2)={
plotinit(0); plotcolor(0,3); \\blue
plotscale(0, -size,size, -size,size);
\\plotscale(0, 0,size, 0,size);
plotmove(0, 0,0);
plotpspiralz(size,lim,ai,di,lim2);
plotdraw([0,size,size]);
}
 
{\\ Executing:
Spiralz(640,2,3.0,3.0,128); \\Spiralz1.png
}
 
Output:
> Spiralz(640,2,3.0,3.0,128);  \\Spiralz1.png
 *** Spiralz: size=640 lim=2 ai=3.000 di=3.000 lim2=128

Phix[edit]

Space toggles the timer, '+' increases speed (up to 100 FPS), '-' decreases speed. 'M' toggles "mod360", which inverts the angle every 360/2PI or so, since sin/cos accept arguments in radians not degrees (and mod 2*PI changes nothing), producing non-true polyspirals, but quite interesting nevertheless.

--
-- demo\rosetta\Polyspiral.exw
-- ===========================
--
include ..\pGUI\pGUI.e
 
Ihandle dlg, canvas, timer
cdCanvas cddbuffer, cdcanvas
 
constant TITLE = "Polyspiral"
 
atom incr = 0
bool mod360 = false
 
procedure Polyspiral(atom x1, y1)
atom angle = incr
integer len = 5
incr += 0.05
if mod360 then
incr = mod(incr,360)
end if
for i=1 to 150 do
atom x2 = x1 + cos(angle)*len
atom y2 = y1 + sin(angle)*len
cdCanvasSetForeground(cddbuffer, i*#200+i*#40+i*#10)
cdCanvasLine(cddbuffer, x1, y1, x2, y2)
{x1, y1} = {x2, y2}
len += 3
angle += incr
if mod360 then
angle = mod(angle,360)
end if
end for
end procedure
 
function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/)
integer {w, h} = IupGetIntInt(canvas, "DRAWSIZE")
cdCanvasActivate(cddbuffer)
cdCanvasClear(cddbuffer)
Polyspiral(w/2, h/2)
cdCanvasFlush(cddbuffer)
integer ms = IupGetInt(timer,"TIME")
IupSetStrAttribute(dlg, "TITLE", "%s (timer=%d [%g FPS], angle %3.2f%s)",
{TITLE,ms,1000/ms,incr,iff(mod360?" (mod360)":"")})
return IUP_DEFAULT
end function
 
function timer_cb(Ihandle /*ih*/)
IupUpdate(canvas)
return IUP_IGNORE
end function
 
function map_cb(Ihandle ih)
cdcanvas = cdCreateCanvas(CD_IUP, ih)
cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas)
cdCanvasSetBackground(cddbuffer, CD_WHITE)
cdCanvasSetForeground(cddbuffer, CD_GRAY)
return IUP_DEFAULT
end function
 
function esc_close(Ihandle /*ih*/, atom c)
if c=K_ESC then return IUP_CLOSE end if
if c=' ' then
IupSetInt(timer,"RUN",not IupGetInt(timer,"RUN"))
elsif find(c,"+-") then
-- ('+' increases speed, by decreasing TIME)
IupSetInt(timer,"TIME",max(10,IupGetInt(timer,"TIME")-(','-c)*10))
IupSetInt(timer,"RUN",0)
IupSetInt(timer,"RUN",1)
elsif upper(c)='M' then
mod360 = not mod360
end if
return IUP_CONTINUE
end function
 
procedure main()
IupOpen(join_path({"..","pGUI"},1))
 
canvas = IupCanvas(NULL)
IupSetAttribute(canvas, "RASTERSIZE", "640x640")
IupSetCallback(canvas, "MAP_CB", Icallback("map_cb"))
IupSetCallback(canvas, "ACTION", Icallback("redraw_cb"))
 
timer = IupTimer(Icallback("timer_cb"), 20)
 
dlg = IupDialog(canvas)
IupSetAttribute(dlg, "TITLE", TITLE)
IupSetCallback(dlg, "K_ANY", Icallback("esc_close"))
 
IupShow(dlg)
IupSetAttribute(canvas, "RASTERSIZE", NULL)
IupMainLoop()
IupClose()
end procedure
 
main()

zkl[edit]

PolySprial.zkl.gif

If you click on the image, it is animated.

Uses the PPM class from http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#zkl

w,h:=640,640;
bitmap:=PPM(w,h,0xFF|FF|FF); // White background
angleIncrement:=(3.0).toRad();
while(True){
r,angle:=0.0, 0.0;
ao,len,inc:=w/2, 2.5, angleIncrement+(130.0).toRad();
foreach c in (128){
s,a:=r + len, angle + inc;
x,y:=r.toRectangular(angle);
u,v:=r.toRectangular(a);
c=c.shiftLeft(21) + c.shiftLeft(10) + c*8; // convert c to a RGB
bitmap.line(ao+x,ao+y, ao+u,ao+v, c);
r,angle=s,a;
}
bitmap.writeJPGFile("polyspiral.zkl.jpg");
bitmap.fill(0xFF|FF|FF); // White background
angleIncrement=(angleIncrement + 0.05);
Atomic.sleep(3);
}