Terrain gizmo

[Josh]

This is the code I used to create the terrain gizmo the editor uses:

    auto terrainwidget = CreateModel(NULL);
    int sides = 128;
    float th = 0.5 * 0.1;
    float x, y, a;
    int i = 0;
    CreateModel(NULL)->SetParent(terrainwidget);
    CreateModel(NULL)->SetParent(terrainwidget);
    auto mtl = CreateMaterial();
    mtl->SetShaderFamily(LoadShaderFamily("Shaders/Unlit.fam"));
    mtl->SetTexture(LoadTexture(GetPath(PATH_DESKTOP) + "/terraingizmo.dds"));

    for (int i = 0; i < 2; ++i)
    {
        auto mesh = terrainwidget->kids[i]->As<Model>()->AddMesh();
        if (i == 1) terrainwidget->kids[i]->SetColor(1, 1, 0, 1);
        mesh->SetMaterial(mtl);
        for (int n = 0; n < sides; ++n)
        {
            a = float(n) / float(sides) * 360.0f;
            x = Cos(a);
            y = Sin(a);
            mesh->AddVertex(x * (1.0 - float(i) * 0.5), 0, y * (1.0 - float(i) * 0.5), 0, 1, 0, 1, 0);
            mesh->AddVertex(x * (1.0 - float(i) * 0.5 - th), 0, y * (1.0 - float(i) * 0.5 - th), 0, 1, 0, 0, 0);
            if (n > 0)
            {
                mesh->AddPrimitive(n * 2 + 1, n * 2 + 0, (n - 1) * 2 + 0);
                mesh->AddPrimitive((n - 1) * 2 + 0, (n - 1) * 2 + 1, n * 2 + 1);
                if (n == sides - 1)
                {
                    mesh->AddPrimitive(1, 0, n * 2 + 0);
                    mesh->AddPrimitive(n * 2 + 0, n * 2 + 1, 1);
                }
            }
        }
    }
    terrainwidget->Save(GetPath(PATH_DESKTOP) + "/terrain.gltf");