// shaders/my_gradient.frag
#version 460 core
#include <flutter/runtime_effect.glsl>

uniform vec2 uSize; // The size of the area being drawn
uniform float uTime;

out vec4 fragColor;

uniform vec3 uColor;

void main() {
  // FlutterFragCoord() gives the pixel coordinate.
  // Divide by uSize to get normalized coordinates (uv) between 0.0 and 1.0.
  vec2 uv = FlutterFragCoord().xy / uSize;

  // Define two colors for the gradient.
  vec4 color1 = vec4(1.0, 0.0, 0.0, 1.0); // Dark Blue
  vec4 color2 = vec4(uColor, 1.0); // Orange/Red

  fragColor = mix(color1, color2, sin(-uTime));
}