path: root/tools.py

#!/usr/bin/python
"""
This file is part of the 'Bridge' Project

Code:   http://git.sugarlabs.org/bridge
        git clone git://git.sugarlabs.org/bridge/mainline.git

This file was originally part of the 'Physics' Project
Physics is a 2D Physics Playground for Kids (supporting Box2D2)
Physics Copyright (C) 2008, Alex Levenson, Brian Jordan
Elements Copyright (C) 2008, The Elements Team, <elements@linuxuser.at>

Wiki:   http://wiki.laptop.org/wiki/Physics
IRC:    #olpc-physics on irc.freenode.org

Code:   http://git.sugarlabs.org/physics
        git clone git://git.sugarlabs.org/physics/mainline.git

License:  GPLv3 http://gplv3.fsf.org/
"""

import pygame
from elements import box2d
from pygame.locals import *
from helpers import *
from inspect import getmro
import math
from gettext import gettext as _

def distance(pt1, pt2):
    """Returns the L_2 norm distance between two points.
    This is the common distance formula that most people know.
    """ 
    return math.sqrt((pt1[0] - pt2[0]) ** 2 + (pt1[1] -pt2[1]) ** 2)

def distance2(pt1, pt2, amount):
    """Returns True or False if the distance between points pt1 and pt2
    is less than the squared amount. 
    """
    if amount == float('inf'): 
        return True
    return ((pt1[0] - pt2[0]) ** 2 + (pt1[1] - pt2[1]) ** 2) <= (amount**2)    

# tools that can be used superlcass
class Tool(object):
    """Tool class implements the event handling of the activity
    toolbar buttons.  It interacts with the world to add, remove,
    or move objects that appear on the screen.
    """
    name = "Tool"
    icon = "icon"
    toolTip = "Tool Tip"
    def __init__(self, gameinstance):
        self.game = gameinstance
        self.name = "Tool"

    def handleevents(self, event):
        """Default method of Handling events
        for any Tool class instances.
        """
        handled = True
        # default event handling
        if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
            # bye bye! Hope you had fun!
            self.game.running = False

        elif event.type == KEYDOWN:
            # most of these key shortcuts are not in the documentation of this
            # activity, so they need to be added.
            if event.key == K_SPACE:
                #space pauses
                self.game.bridge.create_train()
                self.game.world.run_physics = not self.game.world.run_physics  
            elif event.key == K_r:
                self.game.bridge.restart()
            elif event.key == K_t:
                self.game.bridge.create_train(force=True)
            elif event.key == K_b:
                self.game.setTool("girder")
            elif event.key == K_c:
                self.game.setTool("circle")
            elif event.key == K_j:
                self.game.setTool("bridgejoint")
            elif event.key == K_g:
                self.game.setTool("grab")
            elif event.key == K_d:
                self.game.setTool("destroy")

        elif event.type == USEREVENT:
            if hasattr(event,"action"):
                if self.game.toolList.has_key(event.action): 
                    self.game.setTool(event.action)
        elif event.type == MOUSEBUTTONDOWN and event.button == 1:
            self.game.canvas.grab_focus()
            handled = False
        else:
            handled = False
        return handled                                     
    def draw(self):
        """default drawing method doesn't draw anything
        """
        pass
    def cancel(self):
        """default cancel method doesn't do anything
        """
        pass

    def to_b2vec(self, point):
        """returns something about adding the point to a to_b2vec
        """
        return self.game.world.add.to_b2vec(point)

# The circle creation tool        
class CircleTool(Tool): 
    """The circle tool was used for testing.
    It probably should be removed
    """
    icon = "circle"
    toolTip = _("Circle")
   
    def __init__(self, gameinstance):
        Tool.__init__(gameinstance)
        self.name = "Circle"
        self.pt1 = None
        self.radius = None
    def handleevents(self, event):
        """Handles events
        """
        # look for default events, and if none are handled then
        # try the custom events 
        if not super(CircleTool, self).handleEvents(event):
            if event.type == MOUSEBUTTONDOWN:
                if event.button == 1:
                    self.pt1 = pygame.mouse.get_pos()                    
            elif event.type == MOUSEBUTTONUP:
                if event.button == 1:                    
                    if self.radius > 1: # elements doesn't like tiny shapes :(
                        self.game.world.add.ball(self.pt1, self.radius,
                        dynamic=True, density=1.0, 
                        restitution=0.16, friction=0.5)                    
                    self.pt1 = None        
                    self.radius = None            
    def draw(self):
        # draw a circle from pt1 to mouse
        if self.pt1 != None:
            self.radius = distance(self.pt1, pygame.mouse.get_pos())
            if self.radius > 3: 
                thick = 3
            else:
                thick = 0
            pygame.draw.circle(self.game.screen, (100, 180, 255), 
                self.pt1,self.radius, thick) 
            pygame.draw.line(self.game.screen, (100, 180, 255), 
                self.pt1,pygame.mouse.get_pos(), 1)  
    def cancel(self):
        self.pt1 = None  
        self.radius = None
   
# The Girder creation tool
class GirderTool(Tool):
    """The Girder tool is used to place a bridge beam
    on the screen.  This class handles the events related to the button.
    """
    #name = "girder"
    icon = "box"
    toolTip = _("Girder")

    def __init__(self, gameinstance):
        Tool.__init__(gameinstance)
        self.name = "Girder" # TODO was "box", why?
        self.pt1 = None        
        self.pt2 = None
        self.theta = None
        self.thickness = 30
        self.max = 300
        self.min = 100
        self.red = 20
        self.green = 20
        self.blue = 20
        self.colordiff = 20
        
    def handleevents(self, event):
        """Handles events
        """
        # look for default events, and if none are handled then
        # try the custom events 
        if not super(GirderTool, self).handleEvents(event):
            if event.type == MOUSEBUTTONDOWN:
                if event.button == 1:
                    self.pt1 = pygame.mouse.get_pos()                    
            elif event.type == MOUSEBUTTONUP:
                if event.button == 1:                                 
                    if self.pt2 != None:
                        self.game.world.set_color(
                            (self.red, self.green, self.blue))
                        self.red += self.colordiff
                        self.green += self.colordiff
                        self.blue += self.colordiff
                        if self.red > 200:
                            self.colordiff *= -1
                        elif self.red < 20:
                            self.colordiff *= -1
                        print self.theta, math.degrees(self.theta)
                        self.game.world.add.rect(((self.pt1[0]+self.pt2[0])/2, 
                            (self.pt1[1]+self.pt2[1])/2), # tuple concluded
                            distance(self.pt1, self.pt2)/2, 
                            self.thickness/2, angle=math.degrees(self.theta), 
                            dynamic=True, density=1.0, 
                            restitution=0.16, friction=0.5)
                        self.game.bridge.box_added()
                        self.game.world.reset_color()
                    self.pt1 = None        
                                
    def draw(self):
        # draw a box from pt1 to mouse
        if self.pt1 != None:
            self.pt2 = pygame.mouse.get_pos()
            self.theta = getAngle(self.pt1, self.pt2)
            if distance2(self.pt1, self.pt2, self.min):
                # too small! force length              
                self.pt2 = (self.pt1[0]+self.min * math.cos(self.theta),
                    self.pt1[1]-self.min*math.sin(self.theta))
            elif not distance2(self.pt1, self.pt2, self.max):
                # too big
                self.pt2 = (self.pt1[0]+(self.max * math.cos(self.theta)), 
                    self.pt1[1]-(self.max * math.sin(self.theta)))         
            pygame.draw.line(self.game.screen, (255, 255, 255),
                self.pt1, self.pt2, 30)
    def cancel(self):
        self.pt1 = None
        #self.rect = None #TODO why is this here?
           
# The grab tool        
class GrabTool(Tool):
    """The grab tool is used to move objects on the screen.
    This class handles the mouse events related to the use of the tool.
    """
    name = "grab"
    icon = "grab"
    toolTip = _("Grab")
    
    def __init__(self, gameinstance):
        Tool.__init__(gameinstance)
        self.name = "Grab"

    def handleevents(self, event):
        """Handles events
        """
        # look for default events, and if none are handled then 
        # try the custom events 
        if not super(GrabTool, self).handleEvents(event):
            if event.type == MOUSEBUTTONDOWN:
                if event.button == 1:
                    # grab the first object at the mouse pointer
                    bodylist = self.game.world.get_bodies_at_pos(
                        event.pos, include_static=False) 
                    if bodylist and len(bodylist) > 0:
                        self.game.world.add.mouseJoint(bodylist[0], 
                            event.pos)               
            elif event.type == MOUSEBUTTONUP:
                # let it go
                if event.button == 1:
                    self.game.world.add.remove_mouseJoint()
            # use box2D mouse motion
            elif event.type == MOUSEMOTION and event.buttons[0]:
                self.game.world.mouse_move(event.pos)
            
    def cancel(self):
        self.game.world.add.remove_mouseJoint()                        
    

# The destroy tool        
class DestroyTool(Tool):
    """The DestroyTool is the button that allows for items in the game
    to be deleted.  This might be used if a part is placed incorrectly
    or to minimize the number of objects used to construct the bridge.
    """
    name = "destroy"
    icon = "destroy"
    toolTip = _("Destroy")
    
    def __init__(self, gameinstance):
        Tool.__init__(gameinstance)
        self.name = "Destroy"
        self.vertices = None
    def handleevents(self, event):
        """Event handler for the Destory tool.
        This is coded in a different style than the joint tool.
        """
        # look for default events, and if none are handled then try 
        # the custom events 
        if not super(DestroyTool, self).handleEvents(event):
            if pygame.mouse.get_pressed()[0]:
                if not self.vertices: 
                    self.vertices = []
                self.vertices.append(pygame.mouse.get_pos())
                if len(self.vertices) > 10:
                    self.vertices.pop(0)
                tokill = self.game.world.get_bodies_at_pos(
                    pygame.mouse.get_pos())
                if tokill:
                    jointnode = tokill[0].GetJointList()
                    if jointnode:
                        joint = jointnode.joint
                        self.game.bridge.joint_deleted(joint)
                        while joint.GetNext():
                            joint = joint.GetNext()
                            self.game.bridge.joint_deleted(joint)
                    self.game.world.world.DestroyBody(tokill[0])
                    self.game.bridge.box_deleted()
            elif event.type == MOUSEBUTTONUP and event.button == 1:
                self.cancel()
    def draw(self):
        # draw the trail
        if self.vertices:
            if len(self.vertices) > 1:
                pygame.draw.lines(self.game.screen, (255, 0, 0), 
                    False, self.vertices, 3)

    def cancel(self):
        self.vertices = None     

# The joint tool        
class BridgeJointTool(Tool):
    """This class is the joint tool used by the activity.
    If an event occurs, which is expected to be a mouse button release,
    then it handles adding the joint to the two world objects 
    """
    name = "bridgejoint"
    icon = "joint"
    toolTip = _("Bridge Joint")
    
    def __init__(self, gameinstance):
        Tool.__init__(gameinstance)
        self.name = "Bridge Joint"
        self.jb1 = self.jb2 = self.jb1pos = self.jb2pos = None

    def handleevents(self, event):
        """Handles all events, but really if the event is not a mouse 
        button up, then it ignores it.
        """
        # look for default events, and if none are handled then try 
        # the custom events 
        if super(BridgeJointTool, self).handleEvents(event):
            return
        if event.type != MOUSEBUTTONUP or event.button != 1:
            return

        bodies = self.game.world.get_bodies_at_pos(event.pos,
            include_static=True)
        if not bodies or len(bodies) > 2:
            return
            
        jointdef = box2d.b2RevoluteJointDef()
        if len(bodies) == 1:
            if not bodies[0].IsStatic():
                # this following if statement has something to do with checking
                # to see if the joint connects to the two sides of the ravine.
                if (event.pos[1] > 550) and (event.pos[0] < 350 or event.pos[0] > 850):
                    jointdef.Initialize(self.game.world.world.GetGroundBody(), 
                        bodies[0], self.to_b2vec(event.pos))
                else:
                    return
            else:
                return                   
        elif len(bodies) == 2: 
            if bodies[0].IsStatic():
                jointdef.Initialize(self.game.world.world.GetGroundBody(), 
                    bodies[1], self.to_b2vec(event.pos))
            elif bodies[1].IsStatic():
                jointdef.Initialize(self.game.world.world.GetGroundBody(), 
                    bodies[0], self.to_b2vec(event.pos))
            else:
                jointdef.Initialize(bodies[0], bodies[1], 
                    self.to_b2vec(event.pos))
        joint = self.game.world.world.CreateJoint(jointdef)
        self.game.bridge.joint_added(joint)

    def draw(self):
        return
    
    def cancel(self):
        self.jb1 = self.jb2 = self.jb1pos = self.jb2pos = None  

def getalltools():
    """This function builds the tool list that is used by the activity
    to construct the toolbar.
    """
    this_mod = __import__(__name__)
    all = [val for val in this_mod.__dict__.values() if isinstance(val, type)]
    alltools = []
    for thistool in all:
        if getmro(thistool).__contains__(Tool) and thistool != Tool: 
            alltools.append(thistool)
    return alltools
            

ALLTOOLS = getalltools()