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authorWalter Bender <walter@sugarlabs.org>2013-12-11 18:24:21 (GMT)
committer Walter Bender <walter@sugarlabs.org>2013-12-11 18:24:21 (GMT)
commit445dc0cc5770f9aa62264efb37c35d5964e41c0f (patch)
tree995e3ec3d512fe6cc5773e9122b58d3ee9301713 /elements/camera.py
parentfdf37546041d212d97f7fa94dd9013589f9f1f57 (diff)
unpacking elements so as to be able to remove cjson dependency
Diffstat (limited to 'elements/camera.py')
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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
+
+ \ No newline at end of file