# Author: Ryan Myers
# Models: Jeff Styers, Reagan Heller


# Last Updated: 6/13/2005
#
# This tutorial provides an example of creating a character
# and having it walk around on uneven terrain, as well
# as implementing a fully rotatable camera.

import direct.directbase.DirectStart
from pandac.PandaModules import *
from direct.interval.IntervalGlobal import *
from direct.gui.DirectGui import *
from direct.actor import Actor
from direct.showbase.DirectObject import *
import random, sys, os, math

SPEED = 0.5

# Figure out what directory this program is in.
MYDIR=os.path.abspath(sys.path[0])
MYDIR=Filename.fromOsSpecific(MYDIR).getFullpath()

# Function to put instructions on the screen.
def addInstructions(pos, msg):
    return OnscreenText(text=msg, style=1, fg=(1,1,1,1),
			pos=(-1.3, pos), align=TextNode.ALeft, scale = .05)

# Function to put title on the screen.
def addTitle(text):
    return OnscreenText(text=text, style=1, fg=(1,1,1,1),
	                pos=(1.3,-0.95), align=TextNode.ARight, scale = .07)

class World(DirectObject):

    def __init__(self):
        
        self.keyMap = {"left":0, "right":0, "forward":0, "cam-left":0, "cam-right":0}
        base.win.setClearColor(Vec4(0,0,0,1))

        # Post the instructions

        self.title = addTitle("Panda3D Tutorial: Roaming Ralph (Walking on Uneven Terrain)")
        self.inst1 = addInstructions(0.95, "[ESC]: Quit")
        self.inst2 = addInstructions(0.90, "[Left Arrow]: Rotate Ralph Left")
        self.inst3 = addInstructions(0.85, "[Right Arrow]: Rotate Ralph Right")
        self.inst4 = addInstructions(0.80, "[Up Arrow]: Run Ralph Forward")
        self.inst6 = addInstructions(0.70, "[A]: Rotate Camera Left")
        self.inst7 = addInstructions(0.65, "[S]: Rotate Camera Right")
        
        # Set up the environment

        self.environ = loader.loadModel(MYDIR+"/models/world")      
        self.environ.reparentTo(render)
        self.environ.setPos(0,0,0)
        
        
        # Create the main character, Ralph

        ralphStartPos = self.environ.find("**/start_point").getPos()
        self.ralph = Actor.Actor(MYDIR+"/models/ralph",
                                 {"run":MYDIR+"/models/ralph-run",
                                  "walk":MYDIR+"/models/ralph-walk"})
        self.ralph.reparentTo(render)
        self.ralph.setScale(.2)
        self.ralph.setPos(ralphStartPos)

        # Create a floater object.  We use the "floater" as a temporary
        # variable in a variety of calculations.
        
        self.floater = NodePath(PandaNode("floater"))
        self.floater.reparentTo(render)

        # Accept the control keys for movement and rotation

        self.accept("escape", sys.exit)
        self.accept("arrow_left", self.setKey, ["left",1])
        self.accept("arrow_right", self.setKey, ["right",1])
        self.accept("arrow_up", self.setKey, ["forward",1])
        self.accept("a", self.setKey, ["cam-left",1])
        self.accept("s", self.setKey, ["cam-right",1])
        self.accept("arrow_left-up", self.setKey, ["left",0])
        self.accept("arrow_right-up", self.setKey, ["right",0])
        self.accept("arrow_up-up", self.setKey, ["forward",0])
        self.accept("a-up", self.setKey, ["cam-left",0])
        self.accept("s-up", self.setKey, ["cam-right",0])

        taskMgr.add(self.move,"moveTask")

        # Game state variables
        self.prevtime = 0
        self.isMoving = False

        # Set up the camera
        
        base.disableMouse()
        base.camera.setPos(self.ralph.getX(),self.ralph.getY()+10,2)
        
        # We will detect the height of the terrain by creating a collision
        # ray and casting it downward toward the terrain.  One ray will
        # start above ralph's head, and the other will start above the camera.
        # A ray may hit the terrain, or it may hit a rock or a tree.  If it
        # hits the terrain, we can detect the height.  If it hits anything
        # else, we rule that the move is illegal.

        self.cTrav = CollisionTraverser()
        self.environ.setCollideMask(BitMask32.bit(1))

        self.ralphGroundRay = CollisionRay()
        self.ralphGroundRay.setOrigin(0,0,1000)
        self.ralphGroundRay.setDirection(0,0,-1)
        self.ralphGroundCol = CollisionNode('ralphRay')
        self.ralphGroundCol.addSolid(self.ralphGroundRay)
        self.ralphGroundCol.setFromCollideMask(BitMask32.bit(1))
        self.ralphGroundCol.setIntoCollideMask(BitMask32.allOff())
        self.ralphGroundColNp = self.ralph.attachNewNode(self.ralphGroundCol)
        self.ralphGroundHandler = CollisionHandlerQueue()
        self.cTrav.addCollider(self.ralphGroundColNp, self.ralphGroundHandler)

        self.camGroundRay = CollisionRay()
        self.camGroundRay.setOrigin(0,0,1000)
        self.camGroundRay.setDirection(0,0,-1)
        self.camGroundCol = CollisionNode('camRay')
        self.camGroundCol.addSolid(self.camGroundRay)
        self.camGroundCol.setFromCollideMask(BitMask32.bit(1))
        self.camGroundCol.setIntoCollideMask(BitMask32.allOff())
        self.camGroundColNp = base.camera.attachNewNode(self.camGroundCol)
        self.camGroundHandler = CollisionHandlerQueue()
        self.cTrav.addCollider(self.camGroundColNp, self.camGroundHandler)

        # Uncomment this line to see the collision rays
        #self.ralphGroundColNp.show()
        #self.camGroundColNp.show()
       
        #Uncomment this line to show a visual representation of the 
        #collisions occuring
        #self.cTrav.showCollisions(render)
       

    
    #Records the state of the arrow keys
    def setKey(self, key, value):
        self.keyMap[key] = value
    

    # Accepts arrow keys to move either the player or the menu cursor,
    # Also deals with grid checking and collision detection
    def move(self, task):

        elapsed = task.time - self.prevtime

        # If the camera-left key is pressed, move camera left.
        # If the camera-right key is pressed, move camera right.

        base.camera.lookAt(self.ralph)
        camright = base.camera.getNetTransform().getMat().getRow3(0)
        camright.normalize()
        if (self.keyMap["cam-left"]!=0):
            base.camera.setPos(base.camera.getPos() - camright*(elapsed*20))
        if (self.keyMap["cam-right"]!=0):
            base.camera.setPos(base.camera.getPos() + camright*(elapsed*20))

        # save ralph's initial position so that we can restore it,
        # in case he falls off the map or runs into something.

        startpos = self.ralph.getPos()

        # If a move-key is pressed, move ralph in the specified direction.

        if (self.keyMap["left"]!=0):
            self.ralph.setH(self.ralph.getH() + elapsed*300)
        if (self.keyMap["right"]!=0):
            self.ralph.setH(self.ralph.getH() - elapsed*300)
        if (self.keyMap["forward"]!=0):
            backward = self.ralph.getNetTransform().getMat().getRow3(1)
            backward.setZ(0)
            backward.normalize()
            self.ralph.setPos(self.ralph.getPos() - backward*(elapsed*5))

        # If ralph is moving, loop the run animation.
        # If he is standing still, stop the animation.

        if (self.keyMap["forward"]!=0) or (self.keyMap["left"]!=0) or (self.keyMap["right"]!=0):
            if self.isMoving is False:
                self.ralph.loop("run")
                self.isMoving = True
        else:
            if self.isMoving:
                self.ralph.stop()
                self.ralph.pose("walk",5)
                self.isMoving = False

        # If the camera is too far from ralph, move it closer.
        # If the camera is too close to ralph, move it farther.

        camvec = self.ralph.getPos() - base.camera.getPos()
        camvec.setZ(0)
        camdist = camvec.length()
        camvec.normalize()
        if (camdist > 10.0):
            base.camera.setPos(base.camera.getPos() + camvec*(camdist-10))
            camdist = 10.0
        if (camdist < 5.0):
            base.camera.setPos(base.camera.getPos() - camvec*(5-camdist))
            camdist = 5.0

        # Now check for collisions.

        self.cTrav.traverse(render)

        # Adjust ralph's Z coordinate.  If ralph's ray hit terrain,
        # update his Z. If it hit anything else, or didn't hit anything, put
        # him back where he was last frame.

        entries = []
        for i in range(self.ralphGroundHandler.getNumEntries()):
            entry = self.ralphGroundHandler.getEntry(i)
            entries.append(entry)
        entries.sort(lambda x,y: cmp(y.getSurfacePoint(render).getZ(),
                                     x.getSurfacePoint(render).getZ()))
        if (len(entries)>0) and (entries[0].getIntoNode().getName() == "terrain"):
            self.ralph.setZ(entries[0].getSurfacePoint(render).getZ())
        else:
            self.ralph.setPos(startpos)

        # Keep the camera at one foot above the terrain,
        # or two feet above ralph, whichever is greater.
        
        entries = []
        for i in range(self.camGroundHandler.getNumEntries()):
            entry = self.camGroundHandler.getEntry(i)
            entries.append(entry)
        entries.sort(lambda x,y: cmp(y.getSurfacePoint(render).getZ(),
                                     x.getSurfacePoint(render).getZ()))
        if (len(entries)>0) and (entries[0].getIntoNode().getName() == "terrain"):
            base.camera.setZ(entries[0].getSurfacePoint(render).getZ()+1.0)
        if (base.camera.getZ() < self.ralph.getZ() + 2.0):
            base.camera.setZ(self.ralph.getZ() + 2.0)
            
        # The camera should look in ralph's direction,
        # but it should also try to stay horizontal, so look at
        # a floater which hovers above ralph's head.
        
        self.floater.setPos(self.ralph.getPos())
        self.floater.setZ(self.ralph.getZ() + 2.0)
        base.camera.lookAt(self.floater)

        # Store the task time and continue.
        self.prevtime = task.time
        return Task.cont


w = World()
run()
