import phong;

uniform Morph
{
	float morph;
};

const float PI = 3.1415926535;
const float OFFSET = 0.001;

#pragma MSP stage(vertex)
vec3 deform(vec3 p)
{
	vec3 d = cos(p*(2.0*PI)+morph)*0.05;
	return p*(1.0+(d.x+d.y+d.z)*sin(morph*0.2));
}

vec4 get_vertex_position() override
{
	return vec4(deform(vertex.xyz), 1.0);
}

vec3 get_vertex_normal() override
{
	vec3 tangent;
	if(abs(normal.x)>abs(normal.y))
		tangent = normalize(vec3(-normal.z, 0.0, normal.x));
	else
		tangent = normalize(vec3(0.0, -normal.z, normal.y));
	vec3 binormal = cross(normal, tangent);

	vec3 xn = deform(vertex.xyz-tangent*OFFSET);
	vec3 xp = deform(vertex.xyz+tangent*OFFSET);
	vec3 yn = deform(vertex.xyz-binormal*OFFSET);
	vec3 yp = deform(vertex.xyz+binormal*OFFSET);

	return normalize(cross(xp-xn, yp-yn));
}