// Radius must stay well outside the floor's footprint (a 20x20 plane has a
// corner-to-center distance of 10*sqrt(2) =~ 14.1) -- orbiting inside that
// puts parts of the floor's own geometry near/behind the camera's view
// direction, which the PSP's legacy GU pipeline can't clip properly and
// drops the whole triangle instead of clipping it.
var CAMERA_ORBIT_RADIUS = 18.0;
var CAMERA_ORBIT_HEIGHT = 10.0;
var CAMERA_ORBIT_SPEED = 0.5;

var cameraOrbitAngle = 0.0;
var cameraPosition = null;

// Orbits the camera around the world origin at a fixed radius/height/
// speed, always looking back at the origin. Called once up front (so the
// very first rendered frame is already positioned correctly) and then
// once per frame via update() below.
function updateCameraOrbit() {
  cameraOrbitAngle += Time.delta * CAMERA_ORBIT_SPEED;

  var eyeX = Math.cos(cameraOrbitAngle) * CAMERA_ORBIT_RADIUS;
  var eyeY = CAMERA_ORBIT_HEIGHT;
  var eyeZ = Math.sin(cameraOrbitAngle) * CAMERA_ORBIT_RADIUS;

  cameraPosition.lookAt(eyeX, eyeY, eyeZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}

// Called once per engine frame (see engineUpdate() -> scriptManagerCall
// Global("update")).
function update() {
  if(cameraPosition) updateCameraOrbit();
}

(function setup() {
  var scene = new Scene();
  scene.setActive();

  // Camera, orbiting the origin (see updateCameraOrbit above).
  var camera = new Entity();
  cameraPosition = camera.add(POSITION);
  camera.add(CAMERA);
  updateCameraOrbit();

  // Static ground plane. Physics ignores the entity's position component --
  // the shape's own normal/distance fully define the plane in world space.
  var plane = new Entity();
  var planePosition = plane.add(POSITION);
  planePosition.setLocalPosition(-10.0, 0.0, -10.0);
  planePosition.setLocalScale(20.0, 1.0, 20.0);

  var planePhysics = plane.add(PHYSICS);
  planePhysics.setBodyType(PHYSICS_BODY_STATIC);
  planePhysics.setShape(PHYSICS_SHAPE_PLANE, 0.0, 1.0, 0.0, 0.0);

  var planeRenderable = plane.add(RENDERABLE);
  planeRenderable.setMesh(0, MESH_PLANE);
  planeRenderable.setColor(128, 128, 128, 255);

  // Player: dynamic capsule body, moved relative to the camera by
  // PLAYER's own update callback (see entityplayer.c).
  var player = new Entity();
  var playerPosition = player.add(POSITION);
  playerPosition.setLocalPosition(0.0, 2.0, 0.0);

  var playerPhysics = player.add(PHYSICS);
  playerPhysics.setShape(PHYSICS_SHAPE_CAPSULE, 0.5, 0.5);

  var playerRenderable = player.add(RENDERABLE);
  playerRenderable.setMesh(0, MESH_CAPSULE);
  playerRenderable.setColor(0, 0, 255, 255);

  player.add(PLAYER);
})();