#version 330 core
in vec3 vs_in_pos;

uniform mat4 view;
uniform mat4 projection;

out vec3 WorldPos;

void main()
{
    WorldPos = vs_in_pos;

    mat4 rotView = mat4(mat3(view));
    vec4 clipPos = projection * rotView * vec4(WorldPos, 1.0);

    gl_Position = -clipPos.xyww; // without the minus sign, it is not visible

}

#version 330 core

in vec3 WorldPos;

out vec4 FragColor;

uniform samplerCube cubeTexture;

void main()
{
    FragColor = vec4(texture(cubeTexture, WorldPos).rgb, 1.0);
}

glDisable(GL_DEPTH_TEST);
glDepthMask(GL_FALSE);

skybox_program.Enable();

skybox_program.SetCubeTexture("cubeTexture", 0, env_map);
skybox_program.SetUniform("view", camera.GetView());
skybox_program.SetUniform("projection", camera.GetProj());

RenderCube();

glDepthMask(GL_TRUE);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);