// Deployment area on a lane: team-coloured border, faint fill and one line per
// formation row (1.5 m apart), plus chevrons at the front that point down the lane.
// UV.x runs across the pad (-1..1), UV.y along it in metres from the rear edge.
shader_type spatial;
render_mode unshaded, blend_mix, depth_draw_never, cull_disabled, shadows_disabled;
uniform vec4 tint : source_color = vec4(.35, .66, 1.0, 1.0);
uniform float pad_length = 7.4;
uniform float row_start = 7.2;
uniform float row_spacing = 1.5;
uniform float strength = 1.0;
uniform float highlight = 0.0;
void fragment() {
	float across = abs(UV.x);
	float along = UV.y;
	// smoothstep needs edge0 < edge1 (reversed edges are undefined in GLSL).
	float border = smoothstep(.86, .93, across) + (1.0 - smoothstep(.08, .22, along)) + smoothstep(pad_length - .22, pad_length - .08, along);
	float rows = 0.0;
	for (int i = 0; i < 5; i++) {
		float at = row_start - float(i) * row_spacing;
		rows += (1.0 - smoothstep(.0, .05, abs(along - at))) * step(across, .8) * .55;
	}
	float chevron = 0.0;
	float front = along - (pad_length - 1.4);
	if (front > 0.0 && front < 1.0) {
		chevron = (1.0 - smoothstep(.0, .12, abs(front - (1.0 - across) * .7 - .15))) * step(across, .55);
	}
	float pulse = .75 + .25 * sin(TIME * 2.4);
	float alpha = clamp(.035 + .045 * highlight + border * .5 + rows * .5 + chevron * .7, 0.0, 1.0);
	// Unshaded colour stays at or below 1, so the pads never trigger bloom.
	ALBEDO = min(tint.rgb * (.8 + .2 * highlight * pulse), vec3(1.0));
	ALPHA = alpha * strength * (.8 + .2 * pulse * highlight);
}