#version 450

uniform mat4 mview;
uniform mat4 mmviewproj;
uniform mat4 mmod;

uniform float t;
const float half_height = 0.855;

varying vec3 pos;
// varying vec3 normal;
// varying vec3 ldir;
varying vec2 tex_coord;
varying vec3 world_normal;

// const vec3 lpos = vec3(0.0, 100.0, -10.0);

/* attributes */
layout(location = 1) in vec3 attr_pos;
layout(location = 2) in vec3 attr_normal;
layout(location = 3) in vec2 attr_tex;

void main()
{
	vec3 sph_pos = normalize(vec3(attr_pos.x, attr_pos.y - half_height, attr_pos.z));

	vec3 sph_normal = sph_pos;
	sph_pos.y += half_height;

	vec3 p = mix(attr_pos, sph_pos, t);
	vec3 n = mix(attr_normal, sph_normal, t);

	gl_Position = mmviewproj * vec4(p, 1.0);

	pos = (mview * vec4(p, 1.0)).xyz;
	// ldir = (mview * vec4(lpos, 1.0)).xyz;

	// mat3 normal_matrix = mat3(mview);
	// normal = normal_matrix * n;

	tex_coord = attr_tex;
	world_normal = (mmod * vec4(attr_normal, 1.0)).xyz;
}