extern crate gml;

use gml::*;

#[test]
fn triangle_normal() {
    let a = Vector3::new( 1.0,  3.0, 2.0);
    let b = Vector3::new( 5.0, 11.0, 3.0);
    let c = Vector3::new(-4.0, -8.0,-1.0);
    let triangle_normal = (c - a).cross(b - a).normalize();
    let expected_answer = Vector3::new(0.849837, -0.457604, 0.261488);

    assert!(triangle_normal.eq_approx(expected_answer , 1e-5 ));
}

#[test]
fn matrix_transform() {

    let translate = 3.0f32;
    let rotate    = Vector3f::new(4.0, 7.0, 5.0);

    let projection     = perspective(45.0f32, 4.0f32 / 3.0f32, 0.1f32, 100.0f32);
    let view_translate = Matrix4x4f::unit().translate( Vector3::new(0.0f32, 0.0f32, -translate));
    let view_rotate_x  = view_translate.rotate(rotate.y, Vector3f::new(-1.0, 0.0, 0.0));
    let view           = view_rotate_x.rotate(rotate.x, Vector3f::new(0.0, 1.0, 0.0));
    let model          = Matrix4x4f::unit().scale(Vector3f::new_s(0.5));
    let mvp            = projection * view * model;

    let expect = Matrix4x4f::new(-0.439393,  0.445646, -0.285849, -0.285278,
                                  0.0     ,  0.675719,  0.329151,  0.328493,
                                 -0.508739, -0.384901,  0.246885,  0.246392,
                                  0.0     ,  0.0     ,  3.006006,  3.0      );

    assert!(mvp.eq_approx(expect, 1e-5) );
}