edge.fs

precision highp float;

varying vec3 v_position;
varying float v_opacity;

uniform vec2 mouse;
uniform float elapsed;

void main() {
  float change = 0.0008;

  float r = cos(elapsed * change);
  float g = sin(elapsed * change);
  float b = sin(elapsed * change);

  float signR = r / abs(r);
  float signG = g / abs(g);
  float signB = b / abs(b);

  float mouseX = abs(mouse.x);
  float mouseY = abs(mouse.y);

  r = (r / 2.0 + 0.5) * v_position.x * mouseX;
  g = (g / 2.0 + 0.5) * v_position.y * mouseY;
  b = (b / 2.0 + 0.5) * v_position.x * mouseX;

  // r = pow(r, 1.2) * signR;
  // g = pow(g, 1.2) * signG;
  // b = pow(b, 1.2) * signB;

  float mouseDistance = distance(mouse, v_position.xy);
  r += max(0.0, 0.1 - mouseDistance) * (sin(elapsed / 10.0) / 2.0 + 0.5);
  g += max(0.0, 0.1 - mouseDistance) * (cos(elapsed / 9.0) / 2.0 + 0.5);
  b += max(0.0, 0.1 - mouseDistance) * (sin(elapsed / 8.0) / 2.0 + 0.5);

  r = max(0.05, min(0.85, r));
  g = max(0.1, min(0.9, g));
  b = max(0.15, min(0.95, b));

  float opacity = v_opacity * 2.0;

  gl_FragColor = vec4(r, g, b, opacity);
}