Spherical Lissajous Shader

I implemented the spherical Lissajous curve as a shader with Shadertoy.

https://www.shadertoy.com/view/3f2yRK

Procedural Texture Filter System Variables

 Affinity Photo's Procedural Texture Filter System Variables

x, y, rx, ry, w, h, pi

x is the horizontal pixel coordinate position beginning with 0 at the left edge of the document and increasing toward the right by 1 for each pixel.

y is the vertical pixel coordinate position beginning with 0 at the top edge of the document and increasing downward by 1 for each pixel.

rx and ry are relative pixel coordinates. These coordinates allow repositioning of the coordinate system in two ways. Double-clicking the mouse on the document moves the origin (0,0) to the current position of the mouse. Click and dragging moves the coordinate system from the current position to the position you drag it to.

w is the width of the document in pixels, ie 1024

h is the height of the document in pixels, ie 768

pi is the geometric constant 3.14159265...

RGBA inputs

R contains the pixel information for the red channel in the document. It is not possible to access current image pixels individually from this variable. It is possible to modify the image using the channel outputs.

G contains the pixel information for the green channel.

B contains the pixel information for the blue channel.

A contains the pixel information for the alpha channel.

If the document is in CMYK mode, the letters C, M, Y, and K represent the color pixel information for the document. Note that you won't be able to access your RGB filters if the document is set to CMYK color mode.

p cannot be used as a custom input or as a variable name. p followed by a digit may not be used as a custom input but may be used to define a var variable. This includes p1, p2a, p304, etc.

Variable names must begin with a letter may only consist of numbers and letters, and _ (underscore) characters. Upper and lower case letters are allowed and a1 is not the same variable as A1. Space is not allowed nor are other special characters.

A 1024 x 768 landscape document would have an x value ranging from 0 to 1024, with 0 just to the left of the first pixel and 1024 just to the right of the last pixel. A value of x centered on the first pixel would be .5.

Affinity Photo Procedural Texture Filter: Seigaiha

Seigaiha Pattern

• var v=vec2(x,y)*a/w+vec2(of/2,of/4); // Coordinates with offset
• var v1=fraction(v)-.5; // Mask 1 Coordinates
• var m1=smoothstepn(.5-s1/10,.5+s1/10,length(v1))*osci(v.y); // Mask 1 Positive
• var v2=fraction(v+vec2(0,.5))-.5;  // Mask 2 Coordinates
• var m2=1-smoothstepn(.5-s1/10,.5+s1/10,length(v2))*osci(v.y-.5); // Mask 2 Negative
• var v3=fraction(v+vec2(.5,.75))-.5; // Mask 3 Coordinates
• var m3=1-smoothstepn(.5-s1/10,.5+s1/10,length(v3))*osci(v.y-.25); // Mask 3 Negative
• m1*m2*m3*smoothosc(b*length(v1),s2) // Mask with lines

Affinity Photo Procedural Texture Filter

Affinity Photo Procedural Texture Filter Examples

Affinity Help for PTF

List of PTF Functions

This is a list of all of the PTF functions I am aware of. Those used in linked videos are in bold.

Sign Related Functions

abs sign copysign

Rounding Related Functions

ceil floor fmod fraction irem idiv round roundup rounddown trunc truncate whole

Trig Functions

sin cos tan acos asin atan atan2 pi

Power Related Functions

pow powr sq sqrt 

Statistical Functions

average max mid min

Specialized Math Functions

dim fma rgbtoi

Numeric Range Related Functions

tocui tohcui clamp clampmin clampmax saturate

Geometry and Vector Related Functions

cross dist dist_sq distance dot length length_squared norm normalise normalize

vec2 vec3 vec4 vec5 vec6 tovec3 tovec4 tovec5 tovec6

rev rotl rotr

swap 12 swap 13 swap23 swapxy swapxz swapyz swaprg swaprb swapgb

neg1 neg2 neg3 neg12 negx negy negz negxy negr negg negb negrg

debump

Interpolation Functions

lerp mix scurveinterp scerp sininterp serp cubicinterp cerp cubic scurveinterpolant

scint sininterpolant sint

Step Functions

mapcui step smoothstep smoothsteplin smoothstepsc smoothstepsin smoothstepcs smoothstepsq smoothstepsqi smoothstepcb smoothstepcbi smoothstepsin smoothstepsini smoothstepcr smoothstepcri smoothsteprt smoothsteprti 

stepn smoothstepn smoothstepnlin smoothstepnsc smoothstepncs smoothstepnsq smoothstepsqi smoothstepncb smoothstepncbi smoothstepnsini smoothstepncr smoothstepncri smoothstepncrt smoothstepnrti

Quantization

quantize quantizelin quantizesc quantizesin quantizecs

Oscillators

osc osci oscsc oscsin osccs osccubic oscsq oscsqi osccb osccbi oscpsin oscpsini osccr osccri oscrt oscrti

smoothosc smoothosclin smoothoscsin smoothosccs

osch oschi oschsc oschsin oschcs oschcubic oschsq oschsqi oschcb oschcbi oschpsin oschpsini oschcr oschcri oschrt oschrti

smoothosch smoothoschlin smoothoschsin smoothoschcs

Noise

noise noisei noisesc noisesin noisecs noisecubic noisesq noisesqi noisecb noisecbi noisepsin noisepsini noisecr noisecri noisert noiserti

noiseh noisehi noisehsc noisehsin noisehcs noisehcubic noisehsq noisehsqi noisehcb noisehcbi noisehpsin noisehpsini noisehcr noisehcri noisehrt noisehrti

perlin perlinsc perlinsin perlincubic perlincs

perlinh perlinhsc perlinhsin perlinhcubic perlinhcs

cellnoise cellnoise2 cellnoisedist cellnoiseedge

dir diri dirsc dirsin dircs 

udiri udir udirsc udirsin udircs

dir3 dir3i dir3sc dir3sin dir3cs

udir3 udir3i udirsc udir3sin udir3cs

Other functions

var

Reserved/Internal Variable Names

w h x y rx ry R G B pi

Unknown: pc p pt px 

Cannot be used as custom inputs: p p0 p1 p2 p3 p4 p5 (p followed by any number) however, these can be used as variable names.

Operators

+ - * / ^ ( ) . = ; ,

Exponentiation has the same priority as multiplication and division: a*b^c =(a*b)^c not a*(b^c).

I am making a series of video tutorials for Affinity Photo's procedural texture filter. This page provides an index for the functions used in each video.

var vec2 clampmin dot smoothstepn abs oschsin

var vec2 length

var vec2 smoothstep osc

var vec2 perlincubic udirsc smoothstep norm debump dot pow

var vec2 clampmin clampmax osc smoothstep

var vec2 atan2 floor smoothstep length cos

var vec2 floor diri step length fraction

var fraction vec2 atan2 osci pow cos floor length

var fraction vec2 atan2 floor osc length pow cos

var vec2 atan2 floor osc length cos

var vec2 noiseh perlincubic

var vec2 vec3 sqrt fraction step max min smoothstep

var vec2 step perlincubic cellnoisedist

var vec2 fraction smoothstepcs length length max 

var vec2 atan length sin smoothstep

var vec2 atan2 length cellnoise abs dirsc smoothstep

var vec2 cos sin vec3 oscsc osccri oschsc osci dirsc

rev rotl rotr swap12 swap13 swap23 swapxy swapxz swapyz swaprg swaprb swapgb neg1 neg2 neg3 neg12 negx negy negz negxy negr negg negb negrg

var norm vec2 sqrt swapxy fraction  length step atan2 quantize 

var vec2 pow noisei smoothstep osccr osci

fraction oscsq

var vec2 noisei cos sin smoothstep osc quantize perlinhcubic osc average

var normalize vec2 sqrt fraction step length smoothstep cos sin

var vec2 cos sin step osc smoothstep  

var vec2 cellnoise cellnoise2 perlincubic perlinhcubic norm cos sin noisehcubic

var norm vec2 vec3 max oscsqi  perlincubic noisehsc noiseh

var vec2 fraction length atan2 oscsc step

var  norm vec2 cos sin perlincubic perlinhcubic noisehcubic 

var vec2 cos sin normalize perlincubic noisehi

var vec2 cos sin oscsc

osc oscsc  

var norm vec2 cellnoisedist dir noisehcubic perlinhcubic debump dot pow

var vec2 vec3 normalize floor fraction smoothstep noisei lerp cellnoise2 oscsc perlin perlincubic

var vec2 length

var vec2 noisei diri length atan udiri dir3i udir3i dirsc 

var vec3 vec2 smoothstep perlincubic

var normalize vec2 fraction floor step

var normalize vec2 sqrt fraction step length smoothsteplin max abs dot swap12

var vec2oscsc osci max

var vec2 fraction oscrt osc fraction  osch noisehsc max norm debump dot pow

var vec2 abs cellnoisedist perlinhcubic serp norm debump dot pow

var vec2 cellnoisedist quantize

var vec2 pow noisei smoothsteplin average cos sin osccr dirsc osc perlinhcubic

var vec2 vec3 perlinhcubic mapcui osccr step osc

var vec2 cellnoise saturate average

var vec2 perlinhcubic osch clamp

var vec2 mapcui max osccr perlinhcubic

var vec2 oscsin perlinhcubic serp

var vec2 pow cellnoise2 norm debump dot

var vec2 vec3 pow perlincubic dir dot

var vec2 perlincubic norm debump dot pow

var vec2 fraction length vec3 cos abs sin pi 

var vec2 oschsin dir perlinh fraction length

var vec2 fraction atan2 floor noisei smoothstep abs cos length sin step oscsin

var vec2 fraction atan2 length abs cos smoothstep

Race Lights

This is used for an RC racing light tree.  It stays red until you push the button, then stays yellow for 1-3 seconds (randomly), then flashes all colors twice, then stays green until you push the button.  Weak pull-ups are enabled on pin 5 for the button.

/* 
 * File:   RaceLightsMain.c
 * Author: hmikelson
 *
 * Created on June 14, 2019, 1:26 PM
 */

#if defined(__XC)
    #include <xc.h>         /* XC8 General Include File */
#elif defined(HI_TECH_C)
    #include <htc.h>        /* HiTech General Include File */
#endif

#include <stdint.h>        /* For uint8_t definition */
#include <stdbool.h>       /* For true/false definition */
#include <stdlib.h>     /*rand()*/

#pragma config MCLRE=OFF,CP=OFF,WDTE=OFF,FOSC=INTOSCIO
#define _XTAL_FREQ 4000000
uint8_t sGPIO;

void init()
{
    //Configure GPIO Port
    ANSEL =  0b00000000;  //Configure all GPIO pins as digital
    TRISIO = 0b11101000;  //Set GP3 & 5 as input and the rest as outputs
    OPTION_REGbits.nGPPU = 0;
    WPU = 0b00100000;     //Enable weak pullups on GP5
    //Configuer AD Convertor
    ADCON0 = 0x00;        //AD disabled
    ADRESH = 0x00;        //Init the AD Register
    //Configure Comparator
    CMCON0 = 0xFF;   // Comparator is turned off
    CMCON1 = 0x00;   // Comparator is turned off
    //Interrupt configuration
    INTCON = 0x00;   //Disable all interrupts
}

void vdelay(int n)
{
    int i;
    for (i=0;i<=n;i++)
    {
     __delay_ms(150);
    }
}

void main()
{
uint8_t r, db_cnt;

 init();
 GPIO = 0b00000001;
 __delay_ms(100);
 GPIO = 0b00000010;
 __delay_ms(100);
 GPIO = 0b00000100;
 __delay_ms(100);
 GPIO = 0b00000000;                                      
 while(1)
  {
   GPIO = 0b00000001;
   __delay_ms(200);
   for (db_cnt = 0; db_cnt <= 10; db_cnt++)
    {
     __delay_ms(10);
     if (GPIObits.GP5 == 1)
      db_cnt = 0;
    }
   GPIO = 0b00000010;
   r = rand()%15;
   __delay_ms(250);
   vdelay(r);
   __delay_ms(250);
   GPIO = 0b00000001;
   __delay_ms(50);
   GPIO = 0b00000010;
   __delay_ms(50);
   GPIO = 0b00000100;
   __delay_ms(50);
   GPIO = 0b00000001;
   __delay_ms(50);
   GPIO = 0b00000010;
   __delay_ms(50);
   GPIO = 0b00000100;
   __delay_ms(50);
   GPIO = 0b00000100;
   __delay_ms(200);
   for (db_cnt = 0; db_cnt <= 10; db_cnt++)
    {
     __delay_ms(10);
     if (GPIObits.GP5 == 1)
      db_cnt = 0;
    }   
  }
}

Back Up Robot

Code for autonomous robot with PIR motion detection and ultrasound distance sensor.  Distance sensing decreases the chance of the robot getting stuck.  Robot also plays sounds while moving.

/* 
 * File:   BackupBotMain.c
 * Author: hmikelson
 *
 * Created on January 12, 2019, 11:32 AM
 * 
 * This program is used to control a robot with PIC16f1825 microcontroller
 * Uses a customized circuit board with a 1 watt amplified speaker
 * high intensity LED
 * Ultrasound sensor, and PIR sensor
 * Two motors: Forward, backward, right, left, stop
 * 6V battery power
 * Gear driven wheels
 */

#include <xc.h>
#include <stdio.h>
#include <stdlib.h>

#pragma config MCLRE=OFF,CP=OFF,WDTE=OFF,FOSC=INTOSC
#define _XTAL_FREQ 16000000
unsigned char sPORTA=0b00000000, sPORTC=0b00000000, pwmax=63;

void init()
{
 //Configure GPIO Port
 //RA0=BI2,RA1=BI1,RA2=Stby,RC0=AI1,RC1=AI2,RC2=PWMA&B
 //RC3=PIR,RC4=Trig,RC5=Echo,RA3=NA,RA4=Audio,RA5=LED
 //ANSELC= 0b00000000; //Must disable analog inputs to read digital in
 TRISA = 0b11000000;  //O=all
 TRISC = 0b11101000; //I=3,5
 OSCCONbits.IRCF = 0b1111;
 OSCCONbits.SCS = 0b00;
 //Enable analog input on C3
 ANSELCbits.ANSC3 = 1;
 ADCON0 = 0b00011101; //Channel (CHS4:0 bits 6-2),ADON bit 1 enable Analog
 ADCON1bits.ADCS = 0b111; // clock select dedicated osc 
 ADCON1bits.ADNREF = 0; //neg ref
 ADCON1bits.ADPREF = 0; //config + voltage with vdd
 ADCON1bits.ADFM = 1; //format left justified
 ADRESH = 0x00;        //Init the AD Register
}

void vdelay(int n)
 {
  int i;
  for (i=0;i<=n;i++)
   {
    __delay_us(5);
   }
 }

// Read voltage from input
int read_v()
 {
  int val,v1,v2;
  __delay_ms(1);
  ADCON0bits.GO_nDONE = 1;
  while(ADCON0bits.GO_nDONE == 1);
  return (ADRESH<<8) + ADRESL;
 }

/* 
 * Get distance from ultra sound sensor
 * Sensor on pins C4 Trig, C5 Echo
 * 
 */
int getdist()
 {
  int i=0;
  sPORTC = sPORTC & 0b11101111;
   PORTC = sPORTC;
   __delay_us(40);
  sPORTC = sPORTC | 0b00010000;
   PORTC = sPORTC;
   __delay_us(10);
  sPORTC = sPORTC & 0b11101111;
   PORTC = sPORTC;
  while((PORTCbits.RC5 == 0) && (i<5000)) //Wait but not forever
   {
    i++;
   }
  i=0;
  while ((PORTCbits.RC5 == 1) && (i<1000)) //Wait but not forever
   {
    i++;
   }
  return i;
 }

// Drive robot forward
void RobotFd(int time, unsigned char speed)
 {
  int i, j;
  for (i=0;i<time;i++)
   {
    for (j=0;j<pwmax;j++)
     {
      if (j<speed)
       {
         PORTA = 0b00111110;  // LED,Aud,MCLR,En,BI2,BI1
        sPORTC=0b00000110 | sPORTC;
        sPORTC=0b11111110 & sPORTC;
         PORTC = sPORTC;  // Eco,Trg,PIR,PWM,AI1,AI2
        vdelay(pwmax/speed);
       }
      else
       {
         PORTA = 0b00000110;
        sPORTC = 0b00000010 | sPORTC;
        sPORTC = 0b11111010 & sPORTC;
         PORTC = sPORTC;
        vdelay(pwmax/speed);
       }       
     }    
   }
 }

// Move Robot backward
void RobotBk(int time, unsigned char speed)
 {
  int i, j;
  for (i=0;i<time;i++)
   {
    for (j=0;j<pwmax;j++)
     {
      if (j<speed)
       {
         PORTA = 0b00111101;
        sPORTC = 0b00000101 | sPORTC;
        sPORTC = 0b11111101 & sPORTC;
         PORTC = sPORTC;
        vdelay(pwmax/speed);
       }
      else
       {
         PORTA  = 0b00000101;
        sPORTC = 0b00000001 | sPORTC;
        sPORTC = 0b11111001 & sPORTC;
         PORTC = sPORTC;
        vdelay(pwmax/speed);
       }       
     }      
   }
 }

// Move the robot right for time at speed.
void RobotRt(int time, unsigned char speed)
 {
  int i, j;
  for (i=0;i<time;i++)
   {
    for (j=0;j<pwmax;j++)
     {
      if (j<speed)
       {
         PORTA = 0b00111110;
        sPORTC = 0b00000101 | sPORTC;
        sPORTC = 0b11110101 & sPORTC;
         PORTC = sPORTC;
        vdelay(pwmax/speed);
       }
      else
       {
         PORTA = 0b00000110;
        sPORTC = 0b00000001 | sPORTC;
        sPORTC = 0b11111001 & sPORTC;
         PORTC = sPORTC;
        vdelay(pwmax/speed);
       }        
     }        
   }
 }

//Move the Robot Left for given time and speed.
void RobotLt(int time, unsigned char speed)
{
 int i, j;
 for (i=0;i<time;i++)
  {
   for (j=0;j<pwmax;j++)
    {
     if (j<speed)
      {
        PORTA = 0b00111101;
       sPORTC = 0b00000110 | sPORTC;
       sPORTC = 0b11111110 & sPORTC;
        PORTC = sPORTC;
       vdelay(pwmax/speed);
      }
     else
      {
        PORTA = 0b00000101;
       sPORTC = 0b00000010 | sPORTC;
       sPORTC = 0b11111010 & sPORTC;
        PORTC = sPORTC;        
       vdelay(pwmax/speed);
      }      
    }     
  }
}

// Robot stops for the given amount of time
void RobotSt(int time)
{
    int i;
    for (i=0;i<time;i++)
     {
      PORTA = 0b00000100;
      sPORTC = 0b00000100 | sPORTC;
      sPORTC = 0b11111100 & sPORTC;
      PORTC = sPORTC;
      __delay_ms(10);
     }

}

void main()
 {
  int mt=100,dist=1000,i;
  unsigned char rspeed, raction, rtime, nacts=30, pir;
  init();

  RobotFd(200,pwmax/1.5);
  RobotRt(200,pwmax/1.5);
  RobotBk(200,pwmax/1.5);
  RobotLt(200,pwmax/1.5);
  while(1)
   {
    while (nacts==0)
     {
      RobotSt(200);
      pir = read_v();
      if (pir>50)
       {
        nacts = 30;
       }           
     }
    dist = getdist();
    if (dist<300)
     {
      RobotBk(mt,pwmax/2);
      RobotRt(mt,pwmax/2);
     }
    else
    {
     RobotFd(mt,pwmax/2);
    }
    nacts = nacts - 1;
    raction=(rand() % 5);
    rtime=(rand() % mt)/2+mt/2;
    rspeed=pwmax/((rand() % 15)+1)+pwmax/5;
    switch (raction)
     {
      case 1:
       RobotFd(rtime,rspeed);
       break;
      case 2:
       RobotBk(rtime,rspeed);
       break;
      case 3:
       RobotLt(rtime,rspeed);
       break;
      case 4:
       RobotRt(rtime,rspeed);
       break;
      default:
       RobotSt(rtime);
       break;
      }
  }
 }

This program creates a lighting effect that includes a very slow fade, strobe lights, and flashing lights.  It uses a 12f683 and pin 3 for input so you need to provide a pull up resistor (10k) and a pull down resistor (1k) when you push the button.  It  does not use an interrupt so you have to wait until the routine gets around to checking on the button, in other words you may have to hold the button down for a while especially during the slow cross fade.  Use a TIP31 for the LEDs (9V->LED->R->TIP31->Gnd) and a high current 7805 power regulator.  9V 2 A DC power supply.

/* 
 * File:   ls5main.c
 * Author: Hans Mikelson
 *
 * Created on December 17, 2014, 8:59 AM
 */

#if defined(__XC)
    #include <xc.h>         /* XC8 General Include File */
#elif defined(HI_TECH_C)
    #include <htc.h>        /* HiTech General Include File */
#endif

#include <stdint.h>        /* For uint8_t definition */
#include <stdbool.h>       /* For true/false definition */
#include <stdlib.h>        /* includes rand() */

#pragma config MCLRE=OFF,CP=OFF,WDTE=OFF,FOSC=INTOSCIO
#define _XTAL_FREQ 4000000
uint8_t sGPIO, gr1=0, gr2=0;  // Global shadow register and random variables

void init()
{
    //Configure GPIO Port
    ANSEL =  0b00000000;  //Configure all GPIO pins as digital
    TRISIO = 0b110001000;  //Set GP3 as input the rest as outputs
    OPTION_REGbits.nGPPU = 0;
    WPU = 0b00000000;     //Disable weak pullups
    //Configuer AD Convertor
    ADCON0 = 0x00;        //AD disabled
    ADRESH = 0x00;        //Init the AD Register
    //Configure Comparator
    CMCON0 = 0xFF;   // Comparator is turned off
    CMCON1 = 0x00;   // Comparator is turned off
    //Interrupt configuration
    INTCON = 0x00;   //Disable all interrupts
}

void vdelay(int n) //Variable time delay
{
    int i;
    for (i=0;i<=n;i++)
    {
     __delay_us(100);
    }
}

void xfade(int n)  //Cross fade between two global random #s
{                  //n controls the very slow fade time
    int j, k, i;
        for (j=0;j<255;j++)
         {
          for (i=0;i<n;i++)
           {
            for (k=0;k<255;k++)
             {
              if (j<k)
               {
                GPIO=gr2;
               }
              else
               {
                GPIO=gr1;
               }
             }
           }
         }
        gr2 = gr1;
        gr1 = rand() & rand();
}

void strobe(int n)  //Create a strobing cross fade
{
    int j, k, i;
        for (j=0;j<63;j++)
         {
          for (i=0;i<1;i++)
           {
            for (k=0;k<63;k++)
             {
              if (j<k)
               {
                GPIO=gr2;
                vdelay(n);
               }
              else
               {
                GPIO=gr1;
                vdelay(n);
               }
             }
           }
         }
        gr2 = gr1;
        gr1 = rand() & rand();
}

void main()
{
    int i=1;
    init();
    GPIO = 0b00000000;

    while(1)
    {
     if (GPIObits.GP3 == 0)
      {
       i=(i+1) % 9;
       GPIO = 0b00000000;
       vdelay(10000);
      }
     switch (i)
      {
       case 1:                  //Medium flash
        GPIO = rand() & rand(); 
        vdelay(4000);
        break;
       case 2:                  //Fast flash 
        GPIO = rand() & rand();
        vdelay(2000);
        break;
       case 3:
           xfade(1);
        break;
       case 4:
           xfade(8);
        break;
       case 5:
           xfade(32);
        break;
       case 6:
           strobe(4);
        break;
       case 7:
           strobe(8);
        break;
       case 8:
           strobe(32);
        break;
      default:                    // Slow flash
       GPIO = rand() & rand();
       vdelay(8000);
       break;
      }
    }
}