Scanline Texture for Godot 3.1 altha 5

scanline_texture

shader_type canvas_item;
uniform sampler2D source;

void vertex() {
  vec2 texCoord;
}

void fragment() {
  vec4 rgba = texture(source, UV);
	vec4 intensity;
	if (fract(FRAGCOORD.y * (0.5 * 4.0 / 3.0)) > 0.5){
    intensity = vec4(0);
	} else {
		intensity = smoothstep(0.2, 0.8, rgba) + normalize(rgba);
	}
	COLOR = intensity * -0.25 + rgba *1.1;
}