Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
Draw a Equilateral Polygon according to the number of vertexes in Processing language 2.1
// Size of display
int DISPLAY_WIDTH = 500;
int DISPLAY_HEIGHT = 500;
// Colours
int BLACK = 0;
int WHITE = 255;
int CENTER_X = 0;
int CENTER_Y = 0;
EquilateralPolygon polygon;
// This class saves coordinate
class Coordinate {
int x;
int y;
// The Constructor is defined with arguments.
Coordinate(float _x, float _y) {
x = int(_x);
y = int(_y);
}
public String toString() {
return x + ", " + y;
}
}
class EquilateralPolygon {
int numVertexes;
int radius;
float[] angles;
Coordinate[] vertexes;
EquilateralPolygon(int _numVertexes, int _radius) {
numVertexes = _numVertexes;
angles = new float[numVertexes];
radius = _radius;
}
public float xVertex(int i, int extra) {
return cos(angles[i]) * (radius + extra);
}
public float yVertex(int i, int extra) {
return sin(angles[i]) * (radius + extra);
}
public Coordinate[] vertexes() {
vertexes = new Coordinate[numVertexes];
float angleForSingleArc = 2 * PI / numVertexes;
for(int i = 0; i < numVertexes; i++) {
// Sum up angles
angles[i] = HALF_PI - angleForSingleArc * i;
float x = xVertex(i, 0);
float y = - yVertex(i, 0);
vertexes[i] = new Coordinate(x, y);
}
return vertexes;
}
// Put tiny circles onto each vertex
public void drawVertexes() {
smooth();
textAlign(CENTER);
int r = 20;
for (int i = 0; i < numVertexes; i++) {
// Draw black circle for the first vertex and draw gray ones for the rest
int colorValue = i == 0 ? 0 : 200;
stroke(colorValue);
strokeWeight(1);
ellipse(vertexes[i].x, vertexes[i].y, r, r);
}
}
public void drawIndexes() {
for (int i = 0; i < numVertexes; i++) {
fill(BLACK);
text(i, vertexes[i].x, vertexes[i].y);
noFill();
}
}
}
void setup() {
size(DISPLAY_WIDTH, DISPLAY_HEIGHT);
background(WHITE);
noLoop();
}
void draw() {
// Displace the drawn polygon by half width and half height of `display`, which means center.
// With `translate`, we can calculate coodinate of each vertex as distance from the center of a
// diagram, where it's coordinate is as (0, 0), and then, displace the polygon to actual coordinate
// of `display`.
translate(DISPLAY_WIDTH / 2, DISPLAY_HEIGHT / 2);
polygon = new EquilateralPolygon(6, 200);
polygon.vertexes();
polygon.drawVertexes();
polygon.drawIndexes();
saveFrame("result.jpg");
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment