‹ pakt22pakt24 ›

pakt23

See /software/p5js/pakt-februari/pakt23/ for a JavaScript version and /software/supercollider/februari-pakt/pakt23/ for accompanying sound code.

#include "cinder/app/App.h"
#include "cinder/cairo/Cairo.h"

using namespace ci;
using namespace ci::app;
using namespace std;

const int WIDTH= 640;
const int HEIGHT= 480;

class pakt23App : public App {
public:
  void setup();
  void draw();
  cairo::SurfaceImage srfOff;
  cairo::Context ctxOff;
  int index;
  float w, h;
  int n;
};

void pakt23App::setup() {
  srfOff= cairo::SurfaceImage(WIDTH, HEIGHT, false);
  ctxOff= cairo::Context(srfOff);
  ctxOff.setSourceRgba(1, 1, 1, 0.02);
  ctxOff.paint();
  ctxOff.setLineWidth(1);
  index= 0;
  w= getWindowWidth();
  h= getWindowHeight();
  n= 250;
}

void pakt23App::draw() {

  float rx= sin(index*0.0024f);
  float ry= sin(index*0.0022f+1.0f);
  float tx= sin(index*0.0016f+2.0f)+rx;
  float ty= sin(index*0.0018f+3.0f)+ry;

  cairo::Context ctx(cairo::createWindowSurface());
  ctxOff.setSourceRgba(1, 1, 1, 0.02);
  ctxOff.paint();

  ctxOff.moveTo(w*0.5f, h*0.5f);
  for(int i= 50; i<n; i++) {
    float t= float(i)/n;
    if(i==50) {
      ctxOff.moveTo((cos(t*M_PI*2*rx*tx)*0.495f*t+0.5f)*w, (sin(t*M_PI*2*ry*ty)*0.495f*t+0.5f)*h);
    } else {
      float c= sin(t*M_PI*2)*0.5f+0.5f;
      ctxOff.setSourceRgba(c, 0.0, 0.0, c);
      ctxOff.lineTo((sin(t*M_PI*2*rx*tx)*0.495f*t+0.5f)*w, (cos(t*M_PI*2*ry*ty)*0.495f*t+0.5f)*h);
      ctxOff.lineTo((cos(t*M_PI*2*rx*tx)*0.495f*t+0.5f)*w, (sin(t*M_PI*2*ry*ty)*0.495f*t+0.5f)*h);
      ctxOff.stroke();
    }
  }
  index++;
  ctx.copySurface(srfOff, srfOff.getBounds());
}

CINDER_APP(pakt23App, Renderer2d, [&]( App::Settings *settings ) {
  settings->setWindowSize( WIDTH, HEIGHT );
  settings->setResizable( false );
})