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"""
This file is part of the 'Elements' Project
Elements is a 2D Physics API for Python (supporting Box2D2)
Copyright (C) 2008, The Elements Team, <elements@linuxuser.at>
Home: http://elements.linuxuser.at
IRC: #elements on irc.freenode.org
Code: http://www.assembla.com/wiki/show/elements
svn co http://svn2.assembla.com/svn/elements
License: GPLv3 | See LICENSE for the full text
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/>.
"""
from locals import *
class Camera:
""" The Camera class. We will see :)
Please also see: http://www.assembla.com/spaces/elements/tickets/31
This class currently handles:
- Scaling factor
- Screen Offset from the World Coordinate System
Inputs from the user have to be checked for them.
- Places to check for it: elements.py, drawing.py, add_objects.py
"""
scale_factor = 1.0 # All coords to the renderer are multiplied with the scale factor in elements.draw()
track_body = None # Body which means to be tracked. Offset is set at each elements.draw()
def __init__(self, parent):
self.parent = parent
def track(self, body):
""" Start tracking a specific body
"""
self.track_body = body
def track_stop(self):
""" Stop tracking a body
"""
self.track_body = None
def center(self, pos, screenCoord=True, stopTrack=True):
""" Centers the camera at given screen coordinates -- in pixel
Typical call: world.camera.center(event.pos)
Problem: Works ONLY WITH screenCoord now!
"""
x, y = pos
x -= self.parent.display_width / 2
y -= self.parent.display_height / 2
if screenCoord:
x /= self.scale_factor
y /= self.scale_factor
# Set the offset
self.inc_offset((x, y), screenCoord, stopTrack)
def set_offset(self, offset, screenCoord=True, stopTrack=True):
""" Set an offset from the screen to the world cs
-- in screen (or world) coordinates and in pixel
"""
# Stop tracking of an object
if stopTrack: self.track_stop()
# If screenCoords, we have to bring them to the world cs
if screenCoord: x, y = self.parent.to_world(offset)
else: x, y = offset
self._set_offset((x/self.parent.ppm, y/self.parent.ppm))
def inc_offset(self, offset, screenCoord=True, stopTrack=True):
""" Increment an offset from the screen to the world cs -- in world coordinates and in pixel
"""
# Stop tracking of an object
if stopTrack: self.track_stop()
# Get Current Offset
x, y = self.parent.screen_offset_pixel
dx, dy = offset
# Bring the directions into the world coordinate system
if screenCoord:
if self.parent.inputAxis_x_left: dx *= -1
if self.parent.inputAxis_y_down: dy *= -1
# Set New Offset
self._set_offset(((x+dx)/self.parent.ppm, (y+dy)/self.parent.ppm))
def _set_offset(self, offset):
""" Set the screen offset to the world coordinate system
(using meters and the world coordinate system's orientation)
"""
x, y = offset
self.parent.screen_offset = (x, y)
self.parent.screen_offset_pixel = (x*self.parent.ppm, y*self.parent.ppm)
def set_scale_factor(self, factor=1.0):
""" Zoom factor for the renderer 1.0 = 1:1 (original)
"""
self.scale_factor = factor
def inc_scale_factor(self, factor=0.0):
""" Increases the zooms for the renderer a given factor
"""
self.scale_factor += factor
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