Default fragment shader

precision mediump float;

//uniform vec4 gl_FragCoord;
uniform vec2 u_resolution;  // screen size (px) {width, height}
uniform vec2 u_mouse;       // mouse cursor position (px) {x, y}
uniform float u_time;       // time in milliseconds since the beginning
uniform float u_deltaTime;  // time in milliseconds since the last frame

varying vec2 vUV;

void main() {
    gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}