Graphing 2D Equations
/**
* Graphing 2D Equations
* by Daniel Shiffman.
*
* Graphics the following equation:
* sin(n*cos(r) + 5*theta)
* where n is a function of horizontal mouse location.
*/
void setup() {
size(640, 360);
}
void draw() {
loadPixels();
float n = (mouseX * 10.0f) / width;
float w = 16.0f; // 2D space width
float h = 16.0f; // 2D space height
float dx = w / width; // Increment x this amount per pixel
float dy = h / height; // Increment y this amount per pixel
float x = -w / 2.0f; // Start x at -1 * width / 2
for (int i = 0; i < width; i++) {
float y = -h / 2.0f; // Start y at -1 * height / 2
for (int j = 0; j < height; j++) {
float r = sqrt(x * x + y * y); // Convert cartesian to polar
float theta = atan2(y, x); // Convert cartesian to polar
// Compute 2D polar coordinate function
float val = sin(n * cos(r) + 5.0f * theta); // Results in a value between -1 and 1
//float val = cos(r);
//float val = sin(theta);
// Map resulting value to grayscale value
pixels[i + j * width] = color((val + 1.0f) * 255.0f / 2.0f);
y += dy; // Increment y
}
x += dx; // Increment x
}
updatePixels();
}