I’m working on an audio visualisation that’s basically supposed to be a circular spectrogram. I have a graph that shows the frequency already and an arc, that evolves based on the time passed. Now I would like to fill the arc with white points based on the amplitude of each frequency, much like here: https://vimeo.com/27135957. Apparently, I need to make a PGraphics that is filled with points, which change from white to black based on the amplitude. Then I need to texture the arc with this graphic. Does anyone know how to do this?

Basically, what I’m working on is related to this: Creating Circular Spectrogram

```
import ddf.minim.*;
import ddf.minim.analysis.*;
import ddf.minim.effects.*;
import ddf.minim.signals.*;
import ddf.minim.spi.*;
import ddf.minim.ugens.*;
Minim minim;
AudioPlayer song;
FFT fft;
PGraphics pg;
PShape arc;
float deg = 90;
float rad = radians(deg);
void setup()
{
size(1000, 1000);
minim = new Minim(this);
song = minim.loadFile("Anthology.mp3");
song.play();
fft = new FFT(song.bufferSize(), song.sampleRate());
pg = createGraphics(width, height);
}
void draw()
{
background(0);
fft.forward(song.mix);
for (int i = 0; i < fft.specSize(); i++)
{
pushMatrix();
stroke(255);
line(i, height, i, height - fft.getBand(i)*0.5);
popMatrix();
println(fft.getBand(i));
//Map Amplitude to 0 → 255, fill with points and color them
float brightness = map(fft.getBand(i), -1, 1, 0, 255);
pg.beginDraw();
pg.endDraw();
fill(255, 255, 255,);
noStroke();
float evolution = radians(map(song.position(), 0, song.length(), 90, 450));
//Put PGraphics as texture on the arc
texture(pg);
arc(height/2, height/2, height-100, height-100, rad, evolution, PIE);
}
}
```