Color Gradients 1-9

clrGrad_1_9.pde

size(512, 256, P2D);

color start = 0xff00ffff;
color stop = 0xffff00ff; 
color clear = 0x00ffff00;

float count = 64;
float centerX = width * 0.5;
float centerY = height * 0.5; 
float stopRad = max(centerX, centerY) - 2.5; 
float startRad = stopRad * 0.25; 
float radius = startRad;
float angle;
float step;

background(0xffffffff);
noStroke();

beginShape(TRIANGLE_FAN);
for (int i = 0; i < count; ++i) {
  step = i / count;
  radius = lerp(startRad, stopRad, step);
  angle = step * TWO_PI;
  fill(i % 2 == 0 ? clear
    : lerpColor(start, stop, step));
  vertex(centerX + cos(angle) * radius, 
    centerY + sin(angle) * radius);
}
endShape(CLOSE);