#type vertex

#version 330 core
layout (location = 0) in vec3 aPos;
out vec3 WorldPos;
uniform mat4 projection;
uniform mat4 view;
void main()
{
    WorldPos = aPos;
    gl_Position = projection * view * vec4(WorldPos, 1.0);
}

#type fragment

#version 330 core
out vec4 FragColor;
in vec3 WorldPos;
uniform sampler2D equirectangularMap;
const vec2 invAtan = vec2(0.1591, 0.3183);
vec2 SampleSphericalMap(vec3 v)
{
    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
    uv *= invAtan;
    uv += 0.5;
    return uv;
}
void main()
{
    vec2 uv = SampleSphericalMap(normalize(WorldPos));
    vec3 color = texture(equirectangularMap, uv).rgb;
    FragColor = vec4(color, 1.0);
}