shader_type spatial;
render_mode unshaded, blend_add, depth_draw_never, cull_disabled;

uniform vec3 caustic_color : source_color = vec3(0.5, 0.8, 1.0);
uniform float intensity : hint_range(0, 3) = 1.5;
uniform float scale = 8.0;
uniform float speed = 0.5;

float caustic_pattern(vec2 uv) {
	float t = TIME * speed;
	vec2 p = uv * scale;
	float c = 0.0;
	c += sin(p.x + t) * 0.5;
	c += cos(p.y + t * 0.7) * 0.5;
	c += sin(p.x * 0.7 + p.y * 0.5 + t * 1.3) * 0.3;
	c = abs(c);
	c = smoothstep(0.2, 0.0, c);
	return c;
}

void fragment() {
	vec2 uv = UV * 2.0 - 1.0;
	float c1 = caustic_pattern(uv);
	float c2 = caustic_pattern(uv * 1.3 + vec2(0.5, 0.3));
	float caustics = (c1 + c2 * 0.5) * intensity;

	// Fade avec profondeur
	float depth_fade = clamp((VERTEX.y + 60.0) / 80.0, 0.0, 1.0);
	caustics *= depth_fade;

	ALBEDO = caustic_color * caustics;
	ALPHA = caustics;
}