c_rotate

c_rotate(ENTITY* entity, ANGLE* angle, var mode)

Performs a collision detection of the given entity against its environment while rotating it by the given Euler angles. When the entity has a non-symmetrical collision shape and obstacles are nearby, use this function to rotate an entity rather than directly modifying its angles. Otherwise the entity could end up within another object on rotation.

Parameters:

entity	Entity to be rotated
angle	Rotation angle
mode	Collision and rotation mode, see below.

The following mode combinations are available:

IGNORE_YOU	Ignores the you entity on collision detection.
IGNORE_FLAG2	A7.73 Ignores all entities with FLAG2 set.
IGNORE_PASSABLE	Ignores all passable blocks and entities
IGNORE_PASSENTS	Ignores passable model and sprite entities
IGNORE_WORLD	Ignores all level blocks and terrains (useful for doors).
IGNORE_MAPS	Ignores all map entities.
IGNORE_MODELS	Ignores all models.
IGNORE_SPRITES	Ignores all sprites.
IGNORE_PUSH	Ignores all entities with a lower push or same group value than the given entity. For ignoring certain entity groups, call c_ignore before c_rotate.
GLIDE	Attempts to displace the entity origin when hitting an obstacle, in a way that the rotation can still be performed. Useful for rotating a nonsymmetrical actor.
USE_AXIS USE_AXISR	Doesn't rotate about world coordinates, but about the entities' coordinate system. USE_AXIS rotates the entity angle by the angle parameter (like ang_add), USE_AXISR rotates the angle parameter by the entity angle (like ang_rotate). This is required for rotating an arbitrarily orientated object, like an airplane or a spaceship, with collision detection. See ang_add for details.
USE_AABB	Rotates the entity without any collision detection.

Returns:

> 0 - Rotation successful.
<= 0 - Entity could not be rotated, f.i. due to obstacles.

Modifies:

entity.pan, tilt, roll	Entity angles
entity.x, y, z	Entity position (when GLIDE is enabled) .
normal	Normal vector of hit polygon
bounce	Bounce vector of hit polygon
event_type	Type of triggered event

Remarks:

Call c_setminmax for using the object's real bounding box before rotating.
On collision, c_rotate can trigger collision events just like c_move.
For using relative rather than absolute rotation, use USE_AXIS or USE_AXISR.
If an entities' collision ellipsoid is symmetrical in x and y direction (which is the case for most actors), performing collision detection on rotation about the pan axis is not necessary. In that case set the pan angle directly.
IGNORE_YOU can be used to prevent detection of a certain entity. !! A usual beginner's mistake is setting the IGNORE_YOU flag but not setting the you pointer. This causes the collision detection to return unwanted results because you is modified by many functions, and thus can point to a different entity than expected.
Physics entities must not be rotated directly - apply a torque instead.

Speed:

Fast if USE_AABB is set and USE_AXIS / USE_AXISR is not set; otherwise slow.

Example (lite-C):

action door()
{
  c_setminmax(me);
  while (1)
  {
    if (key_space && my.pan < 180)  
      c_rotate(me,vector(time_step,0,0),IGNORE_WORLD);
    wait(1);
  }
}