triangle_strip.pde

triangle_strip.pde

int x;
int y;
float outsideRadius = 150;
float insideRadius = 100;


void setup()
{
	size(640, 360);
	background(204);
	x = width/2;
	y = height/2;
}


void draw()
{
	background(204);

	int numPoints = int(map(mouseX, 0, width, 6, 60));
	float angleStep = PI / numPoints;

	beginShape(TRIANGLE_STRIP);
	for (int i = 0; i <= numPoints; i++)
	{
		float angle = angleStep * (i * 2);
		float px = x + cos(angle) * outsideRadius;
		float py = y + sin(angle) * outsideRadius;
		vertex(px, py);

		angle = angleStep * (i * 2 + 1);
		px = x + cos(angle) * insideRadius;
		py = y + sin(angle) * insideRadius;
		vertex(px, py);
	}
	endShape();
}