用processing画李萨如曲线

有没有对示波器上变化曲线产生过兴趣，它叫做李萨如曲线：

数学上，利萨茹(Lissajous)曲线（又称利萨茹图形、李萨如图形或鲍迪奇(Bowditch)曲线）是两个沿着互相垂直方向的正弦振动的合成的轨迹

//int n=4;

int p=17;

int q=15;

4:

int a = displayWidth /2 ;

//displayHeight /2 ;

7:

int radius = 2;

//PI / 2 / p;

float miu_max = TWO_PI;

float miu_delta = miu_max / 100;

12:

void setup() {

  14:   size(displayWidth, displayHeight);

  15:   background(0);

  16:   frameRate(2);

17:

  18:   a = displayWidth / 5 ;

  19:   b = a ;

  20: }

21:

void draw() {

23:

  24:     miu += miu_delta;

if (miu >= miu_max)

  26:         miu = 0;

//    if (miu >= miu_max)

//    {

//        miu_delta = -miu_delta;

//        miu += miu_delta;

//    }

//    else if (miu < 0)

//    {

//        miu_delta = -miu_delta;

//        miu += miu_delta;

//    }

37:

  38:     fill(0,0,0,250);

  39:     rect(-1,-1, displayWidth+1, displayHeight+1);

40:

int last_x = -1;

int last_y = -1;

43:

float theta=0;theta<TWO_PI;theta+=TWO_PI/360)

  45:     {

int) (a * sin(p * theta)) + displayWidth /2;

int) (b * sin(q * theta + (miu))) + displayHeight /2;

48:

  49:         colorMode(HSB, 255);

  50:         stroke(90, 255, 255);

  51:         fill(90, 255, 255);

52:

if (last_x != -1 >> last_y != -1)

  54:         {

  55:             line(last_x, last_y, x, y);

  56:             line(last_x-1, last_y, x-1, y);

  57:         }

58:

  59:         last_x = x;

  60:         last_y = y;

61:

//ellipse(x, y, radius, radius);

  63:     }

64:

  65: }