c.py

#
# Copyright 2009-2012 Alex Fraser <alex@phatcore.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import bge

import bat.bmath

@bat.utils.controller
def slow_copy_rot(c):
    '''Slow parenting (Rotation only). The owner will copy the rotation of the
    'sGoal' sensor's owner. The owner must have a SlowFac property:
    0 <= SlowFac <= 1. Low values will result in slower and smoother movement.
    '''

    o = c.owner
    goal = c.sensors['sGoal'].owner
    bat.bmath.slow_copy_rot(o, goal, o['RotFac'])

@bat.utils.controller
def slow_copy_loc(c):
    '''Slow parenting (Location only). The owner will copy the position of the
    'sGoal' sensor's owner. The owner must have a SlowFac property:
    0 <= SlowFac <= 1. Low values will result in slower and smoother movement.
    '''

    o = c.owner
    goal = c.sensors['sGoal'].owner
    bat.bmath.slow_copy_loc(o, goal, o['LocFac'])

@bat.utils.all_sensors_positive
@bat.utils.controller
def copy_trans(c):
    '''Copy the transform from a linked sensor's object to this object.'''
    bat.bmath.copy_transform(c.sensors[0].owner, c.owner)

@bat.utils.owner
def ray_follow(o):
    '''Position an object some distance along its parent's z-axis. The object
    will be placed at the first intersection point, or RestDist units from the
    parent - whichever comes first.
    '''

    p = o.parent

    origin = p.worldPosition
    direction = p.getAxisVect(bat.bmath.ZAXIS)
    through = origin + direction

    hitOb, hitPoint, hitNorm = p.rayCast(
        through,        # obTo
        origin,            # obFrom
        o['RestDist'],     # dist
        'Ray',            # prop
        1,                # face normal
        1                # x-ray
    )

    targetDist = o['RestDist']
    if hitOb and (hitNorm.dot(direction) < 0):
        #
        # If dot > 0, the tracking object is inside another mesh.
        # It's not perfect, but better not bring the camera forward
        # in that case, or the camera will be inside too.
        #
        targetDist = (hitPoint - origin).magnitude

    targetDist = targetDist * o['DistBias']

    if targetDist < o['Dist']:
        o['Dist'] = targetDist
    else:
        o['Dist'] = bat.bmath.lerp(o['Dist'], targetDist, o['FollowFac'])

    o.worldPosition = origin + (direction * o['Dist'])

@bat.utils.owner
def orbit_follow(o):
    vectTo = None
    p = o.parent
    origin = p.worldPosition
    try:
        vectTo = o['LastPos'] - origin
    except KeyError:
        o['LastPos'] = o.worldPosition
        return

    zlocal = p.getAxisVect(bat.bmath.ZAXIS)
    zcomponent = vectTo.project(zlocal)
    targetDirection = vectTo - zcomponent
    targetDirection.normalize()
    through = origin + targetDirection

    hitOb, hitPoint, hitNorm = p.rayCast(
        through,        # obTo
        origin,            # obFrom
        o['RestDist'],     # dist
        'Ray',            # prop
        1,                # face normal
        1                # x-ray
    )

    targetDist = o['RestDist']
    if hitOb and (hitNorm.dot(targetDirection) < 0):
        #
        # If dot > 0, the tracking object is inside another mesh.
        # It's not perfect, but better not bring the camera forward
        # in that case, or the camera will be inside too.
        #
        targetDist = (hitPoint - origin).magnitude

    targetDist = targetDist * o['DistBias']

    if targetDist < o['Dist']:
        o['Dist'] = targetDist
    else:
        o['Dist'] = bat.bmath.lerp(o['Dist'], targetDist, o['FollowFac'])

    o['LastPos'] = origin + (targetDirection * o['Dist'])
    o.worldPosition = o['LastPos']
    o.alignAxisToVect(zlocal, 1)
    o.alignAxisToVect(targetDirection, 2)

@bat.utils.all_sensors_positive
@bat.utils.controller
def spray_particle(c):
    '''
    Instance one particle, and decrement the particle counter. The particle will
    move along the z-axis of the emitter. The emitter will then be repositioned.

    The intention is that one particle will be emitted on each frame. This
    should be fast enough for a spray effect. Staggering the emission reduces
    the liklihood that the frame rate will suffer.

    Actuators:
    aEmit:    A particle emitter, connected to its target object.
    aRot:    An actuator that moves the emitter by a fixed amount (e.g. movement
            or IPO).

    Controller properties:
    maxSpeed:    The maximum speed that a particle will have when it is created.
            Actually the particle will move at a random speed s, where 0.0 <= s
            <= maxSpeed.
    nParticles:    The number of particles waiting to be created. This will be
            reduced by 1. If less than or equal to 0, no particle will be
            created.
    '''

    o = c.owner
    if o['nParticles'] <= 0:
        return

    o['nParticles'] = o['nParticles'] - 1
    speed = o['maxSpeed'] * bge.logic.getRandomFloat()
    c.actuators['aEmit'].linearVelocity = (0.0, 0.0, speed)
    c.activate('aEmit')
    c.activate('aRot')

@bat.utils.owner
def billboard(o):
    '''Track the camera - the Z-axis of the current object will be point towards
    the camera.'''

    _, vec, _ = o.getVectTo(bge.logic.getCurrentScene().active_camera)
    o.alignAxisToVect(vec, 2)

@bat.utils.owner
def billboard_yneg_zup(o):
    '''Track the camera - the Y-axis of the current object will be point towards
    the camera.'''

    other = bge.logic.getCurrentScene().active_camera
    _, vec, _ = o.getVectTo(other)
    vec.negate()
    o.alignAxisToVect(vec, 1)
    o.alignAxisToVect(bat.bmath.ZAXIS, 2)

@bat.utils.all_sensors_positive
def makeScreenshot():
    bge.render.makeScreenshot('//Screenshot#.jpg')