Sine Wave
/**
* Sine Wave
* by Daniel Shiffman.
*
* Render a simple sine wave.
*/
int xspacing = 16; // How far apart should each horizontal location be spaced
int w; // Width of entire wave
float theta = 0.0; // Start angle at 0
float amplitude = 75.0; // Height of wave
float period = 500.0; // How many pixels before the wave repeats
float dx; // Value for incrementing X, a function of period and xspacing
float* yvalues; // Using an array to store height values for the wave
void setup() {
size(640, 360);
w = width + 16;
dx = (TWO_PI / period) * xspacing;
yvalues = new float[w / xspacing];
}
void draw() {
background(0);
calcWave();
renderWave();
}
void calcWave() {
// Increment theta (try different values for 'angular velocity' here
theta += 0.02;
// For every x value, calculate a y value with sine function
float x = theta;
for (int i = 0; i < w / xspacing; i++) {
yvalues[i] = sin(x) * amplitude;
x += dx;
}
}
void renderWave() {
noStroke();
fill(255);
// A simple way to draw the wave with an ellipse at each location
for (int x = 0; x < w / xspacing; x++) {
ellipse(x * xspacing, height/2 + yvalues[x], 16, 16);
}
}