class World(DirectObject):
def __init__(self):
#This code puts the standard title and instruction text on screen
self.title = OnscreenText(text="Panda3D: Tutorial - Mouse Picking",
style=1, fg=(1,1,1,1), font = font,
pos=(0.8,-0.95), scale = .07)
self.escapeEvent = OnscreenText(
text="ESC: Quit", font = font,
style=1, fg=(1,1,1,1), pos=(-1.3, 0.95),
align=TextNode.ALeft, scale = .05)
self.mouse1Event = OnscreenText(
text="Left-click and drag: Pick up and drag piece",
style=1, fg=(1,1,1,1), pos=(-1.3, 0.90), font = font,
align=TextNode.ALeft, scale = .05)
self.accept('escape', sys.exit) #Escape quits
base.disableMouse() #Disble mouse camera control
camera.setPosHpr(0, -13.75, 6, 0, -25, 0) #Set the camera
self.setupLights() #Setup default lighting
#Since we are using collision detection to do picking, we set it up like
#any other collision detection system with a traverser and a handler
self.picker = CollisionTraverser() #Make a traverser
self.pq = CollisionHandlerQueue() #Make a handler
#Make a collision node for our picker ray
self.pickerNode = CollisionNode('mouseRay')
#Attach that node to the camera since the ray will need to be positioned
#relative to it
self.pickerNP = camera.attachNewNode(self.pickerNode)
#Everything to be picked will use bit 1. This way if we were doing other
#collision we could seperate it
self.pickerNode.setFromCollideMask(BitMask32.bit(1))
self.pickerRay = CollisionRay() #Make our ray
self.pickerNode.addSolid(self.pickerRay) #Add it to the collision node
#Register the ray as something that can cause collisions
self.picker.addCollider(self.pickerNP, self.pq)
#self.picker.showCollisions(render)
#Now we create the chess board and its pieces
#We will attach all of the squares to their own root. This way we can do the
#collision pass just on the sqaures and save the time of checking the rest
#of the scene
self.squareRoot = render.attachNewNode("squareRoot")
#For each square
self.squares = [None for i in range(64)]
self.pieces = [None for i in range(64)]
for i in range(64):
#Load, parent, color, and position the model (a single square polygon)
self.squares[i] = loader.loadModel("models/samples/chessboard/square")
self.squares[i].reparentTo(self.squareRoot)
self.squares[i].setPos(SquarePos(i))
self.squares[i].setColor(SquareColor(i))
#Set the model itself to be collideable with the ray. If this model was
#any more complex than a single polygon, you should set up a collision
#sphere around it instead. But for single polygons this works fine.
self.squares[i].find("**/polygon").node().setIntoCollideMask(
BitMask32.bit(1))
#Set a tag on the square's node so we can look up what square this is
#later during the collision pass
self.squares[i].find("**/polygon").node().setTag('square', str(i))
#We will use this variable as a pointer to whatever piece is currently
#in this square
#The order of pieces on a chessboard from white's perspective. This list
#contains the constructor functions for the piece classes defined below
pieceOrder = (Rook, Knight, Bishop, Queen, King, Bishop, Knight, Rook)
for i in range (8,16):
#Load the white pawns
self.pieces[i] = Pawn(i, WHITE)
for i in range (48,56):
#load the black pawns
self.pieces[i] = Pawn(i, PIECEBLACK)
for i in range(8):
#Load the special pieces for the front row and color them white
self.pieces[i] = pieceOrder[i](i, WHITE)
#Load the special pieces for the back row and color them black
self.pieces[i+56] = pieceOrder[i](i+56, PIECEBLACK)
#This will represent the index of the currently highlited square
self.hiSq = False
#This wil represent the index of the square where currently dragged piece
#was grabbed from
self.dragging = False
#Start the task that handles the picking
self.mouseTask = taskMgr.add(self.mouseTask, 'mouseTask')
self.accept("mouse1", self.grabPiece) #left-click grabs a piece
self.accept("mouse1-up", self.releasePiece) #releasing places it
#This function swaps the positions of two pieces
def swapPieces(self, fr, to):
temp = self.pieces[fr]
self.pieces[fr] = self.pieces[to]
self.pieces[to] = temp
if self.pieces[fr]:
self.pieces[fr].square = fr
self.pieces[fr].obj.setPos(SquarePos(fr))
if self.pieces[to]:
self.pieces[to].square = to
self.pieces[to].obj.setPos(SquarePos(to))
def mouseTask(self, task):
#This task deals with the highlighting and dragging based on the mouse
#First, clear the current highlight
if self.hiSq is not False:
self.squares[self.hiSq].setColor(SquareColor(self.hiSq))
self.hiSq = False
#Check to see if we can access the mouse. We need it to do anything else
if base.mouseWatcherNode.hasMouse():
#get the mouse position
mpos = base.mouseWatcherNode.getMouse()
#Set the position of the ray based on the mouse position
self.pickerRay.setFromLens(base.camNode, mpos.getX(), mpos.getY())
#If we are dragging something, set the position of the object
#to be at the appropriate point over the plane of the board
if self.dragging is not False:
#Gets the point described by pickerRay.getOrigin(), which is relative to
#camera, relative instead to render
nearPoint = render.getRelativePoint(camera, self.pickerRay.getOrigin())
#Same thing with the direction of the ray
nearVec = render.getRelativeVector(camera,
self.pickerRay.getDirection())
self.pieces[self.dragging].obj.setPos(
PointAtZ(.5, nearPoint, nearVec))
#Do the actual collision pass (Do it only on the squares for
#efficiency purposes)
self.picker.traverse(self.squareRoot)
if self.pq.getNumEntries() > 0:
#if we have hit something, sort the hits so that the closest
#is first, and highlight that node
self.pq.sortEntries()
i = int(self.pq.getEntry(0).getIntoNode().getTag('square'))
#Set the highlight on the picked square
self.squares[i].setColor(HIGHLIGHT)
self.hiSq = i
return Task.cont
def grabPiece(self):
#If a square is highlighted and it has a piece, set it to dragging mode
if (self.hiSq is not False and
self.pieces[self.hiSq]):
self.dragging = self.hiSq
self.hiSq = False
def releasePiece(self):
#Letting go of a piece. If we are not on a square, return it to its original
#position. Otherwise, swap it with the piece in the new square
if self.dragging is not False: #Make sure we really are dragging something
#We have let go of the piece, but we are not on a square
if self.hiSq is False:
self.pieces[self.dragging].obj.setPos(
SquarePos(self.dragging))
else:
#Otherwise, swap the pieces
self.swapPieces(self.dragging, self.hiSq)
#We are no longer dragging anything
self.dragging = False
def setupLights(self): #This function sets up some default lighting
lAttrib = LightAttrib.makeAllOff()
ambientLight = AmbientLight( "ambientLight" )
ambientLight.setColor( Vec4(.8, .8, .8, 1) )
lAttrib = lAttrib.addLight( ambientLight )
directionalLight = DirectionalLight( "directionalLight" )
directionalLight.setDirection( Vec3( 0, 45, -45 ) )
directionalLight.setColor( Vec4( 0.2, 0.2, 0.2, 1 ) )
lAttrib = lAttrib.addLight( directionalLight )
render.attachNewNode( directionalLight )
render.attachNewNode( ambientLight )
render.node().setAttrib( lAttrib )
