[Solved] CSCI 1100 A Bird in the Hand

Part 1: CS 1 BirdsComputer games such as Angry Birds are based on simulating the basic rules of physics, or at leastsome rough approximation to these rules. These simulations involve a simple basic loop where ineach iteration1. The positions and sometimes the velocities of moving objects are both updated by a smallamount.2. Objects are checked for collisions, and changes are made to the simulation based on thesecollisions.While never 100% accurate, realistic looking results and physically useful predictions (for scienti csimulations) can be obtained by making sure the changes in each loop iteration are small.We will apply this idea to a simple version of angry birds called CS 1 Birds. Along the way youwill get practice writing classes and using dictionaries.The simulation occurs over a rectangular region whose lower left and upper right corners arelocations (0; 0) and (1000; 1000). Take note of the playing eld. This is dierent than we usedfor the pokemon homeworks. It now corresponds to the upper right quadrant of a graph. Thesimulation will include birds, pigs, and barriers all represented by circles. Bird, pig and barrierpositions are in oats and correspond to points in cartesian or (x,y) coordinates. The pigs andbarriers are stationary, but the birds will move along a line (no gravity!). Each bird will move inturn, slowing down or stopping when it strikes a pig or a barrier, and stopping when it becomestoo slow or when any part of it goes outside the game rectangle. When a bird strikes a pig, thepig will pop and disappear from the simulation. When it strikes a barrier, the barrier will takedamage, but may or may not disappear depending on its initial strength and how many times ithas been hit. The simulation ends when either all pigs have been popped or when all birds havestopped, whichever occurs rst.We can summarize the possible behaviors as follows: Bird1. y Update the current position by dx and dy2. collide with a pig Decrease x velocity by a factor of 23. collide with a barrier Total speed becomes 04. stops total speed becomes < 6, or the bird circle leaves the eld. Pig1. bird collides with it Pops! Barrier1. collide with a bird Takes mass times speed squared damage. Do not let the strengthgo below 02. crumbles if strength is reduced to 0Input FilesThe input for the exercise will be stored in a single json le. The le encodes a dictionary ofentries for birds, pigs, and barriers. Where each entry is an array of the correct type,birds, pigs, or barriers, and where the elements of each array are a dictionaries of attributes for anindividual. This sounds complicated, but it is not. The code below reads in the le and thenprints out the information for the birds. You can get the information for the pigs by replacing thekey birds with pigs and can get the information on the barriers by using the key barriers.You only need to read the le once.

A simple program to illustrate the use of json and dictionariesfor using the pig, bird and barrier json data.

import jsonfilename = input(Enter the name of the data file => )print(filename)f = open(filename.strip())data = f.read().strip()dictionary = json.loads(data)print()print({} contains the following birds:.format(filename))for bird in dictionary[ birds ]:print({}:
{}.format(bird[ name ], bird))Running this with scenario4.json gives the following output:scenario4.json contains the following birds:Tweety:{ y0 : 12, name : Tweety , mass : 0.5, dy : 5.1, x0 : 10, dx : 4.2, radius : 9}Hawk:{ y0 : 800, name : Hawk , mass : 10.0, dy : -6, x0 : 100, dx : 8, radius : 20}Eddie:{ y0 : 300, name : Eddie , mass : 15, dy : 5.5, x0 : 200, dx : 3.3, radius : 19}Super Chicken:{ y0 : 90, name : Super Chicken , mass : 8, dy : 8.2, x0 : 400, dx : 8, radius : 19}Humming:{ y0 : 400, name : Humming , mass : 0.1, dy : 4.3, x0 : 80, dx : 4.3, radius : 6.1}2We recommend that you run this and play with it to see how it works. You may liberally copyfrom this in generating your own program.Each entry in a bird array will have entries for name, mass, radius, x0, y0, dx anddy, where the entry for name is a string giving the name of the bird, mass is the birds mass (usedto calculate damage to barriers), x0 and y0 specify the birds initial position (center of the circle),radius is the birds radius, and dx and dy specify how far the bird moves in each time step. Allvalues other than name are oats.The entries in the pig array will have a similar format with entries for name, radius, xc,and yc, where name is a string giving the name of the pig, xc and yc specify the pigs centerposition, and radius is the pigs radius. All values other than name are oats.And nally each entry of the barrier array will have entries for name, strength, radius,xc, and yc, where name is a string giving the name of the structure, strength is a measureof how much damage it can take before being destroyed, xc and yc specify the structures position(center of the circle), and radius is the structures radius. All values other than name are oats.Simulation and OutputAt the start of the simulation ask for the scenario le, read in the data, and use it to create lists ofbird, pig and barrier objects. Note that these must be objects, not just the arrays formthe input le. Write classes for birds, pigs and barriers; and use the data from the le to initializeobjects of the classes. You may assume all input is properly formatted, all birds are entirely insidethe bounding rectangle at the start, and none of the birds or pigs intersect each other at the start.You may also assume that each birds movement (dx; dy) is much smaller than the radii of the pigsand barriers so that you do not need to worry about a bird completely passing through a pig or abarrier in one time step.After processing the le your program should have three lists, one of Bird objects, one of Pigobjects and one of Barrier objects. At this point print out the number of birds, the name of eachbird and its starting center location, the number of pigs, and the name of each pig and its centerlocation, the number of barriers, the name of each barrier and its center location. The order shouldbe the order the birds/pigs/barriers were read in. Follow the format of the output examples wehave provided in the separate les.The simulation starts at time 0 and runs until either there are no more pigs, or until all birds haveleft the eld or stopped. All position output should be accurate to 1 decimal place. Please followthe output precisely as shown | it should be fairly straightforwardIn each time step:1. Only one bird will be on the eld at a time. If there is no bird currently on the eld, choosethe next bird and enter it into play. Print a message. For example,Time 0: Tweety starts at (10.0,12.0)2. Increment the time counter3. Move the current bird by its dx and dy values. (To be clear, the rst birds rst step will beat time 1.)4. Check to see if the birds circle intersects the circle of a pig that has not yet been popped.(Intersection occurs when the distance between the two circle centers is less than or equal tothe sum of the two circle radii.) If so,3(a) Print one line giving the time, the name of the bird, the position of the bird, and thename of the pig. For example,Time 25: Freddie at (15.3,19.1) pops Wilbur(b) Pop the pig. One easy thing to do is to remove the pig from the list of pigs.(c) Decrease the dx value (the x speed ONLY) of the bird by 50% (Throughout your codeyou might want to make sure that Python knows that the speed is a oat) Note thatthis changes the direction the bird is heading. Print one more line,Time 25: Freddie at (15.3,19.1) has (dx,dy) = (4.5,5.0)(d) The data we provide is arranged such that only one pig will be struck at a given timestep. Once you have popped the rst pig, you can stop reviewing the rest of the pig list.5. Check to see if the birds circle intersects the circle of a barrier that has not yet crumbled.(Again, intersection occurs when the distance between the two circle centers is less than orequal to the sum of the two circle radii.) If so,(a) Print one line giving the time, the name of the bird, the position of the bird, the nameof the barrier and the barriers strength after the collision. Note that the barrier takesthe birds mass times its speed squared in damage when hit, but be sure to not let thebarrier go below 0 strength.Time 25: Freddie at (15.3,19.1) hits Picket, Strength 0.0(b) If the barriers strength is dropped to 0, the barrier crumbles and an additional messageshould be printedTime 25: Picket crumbles(c) Decrease the dx and dy of the bird to 0. Print one more line,Time 25: Freddie at (15.3,19.1) has (dx,dy) = (0.0,0.0)(d) Again, the data we provide is arranged such that only one barrier will be struck at agiven time step. Once you have struck the rst barrier, you can stop reviewing the restof the barrier list.6. Check two more things in the following order:(a) If the bird reaches a speed below MINSPEED==6, stop moving the bird, remove it fromthe simulation, and move on to the next bird. (Note that the speed ispdx2 + dy2.)When this occurs output the time, the name, the location and the speed the bird, e.g.Time 281: Super Chicken at (668.0,364.7) with speed 4.6 stops(b) If any part of the birds circle has gone outside the rectangle (its x position minus itsradius is less than 0 or its x position plus its radius is greater than 1000, or its y positionminus its radius is less than 0 or its y position plus its radius is greater than 1000) thebird has left the playing eld. When this occurs, output the time, the name and locationof the bird. For example,Time 25: Big-Bird at (975.0,234.0) has left the gameWhen a bird stops or leaves the eld and there are more birds and more pigs left, start thenext bird immediately at its initial location. Output something likeTime 25: Daffy starts at (123.7,88.5)4Just to be clear, the time Day starts is the same time the previous bird (Big-Bird) leavesthe board. Day does not move until the next time, and therefore no tests against pigs orbarriers are needed.7. If all pigs are popped then output a message saying something likeTime 33: All pigs are popped. The birds win!and stop the game.8. Otherwise, if there are no more birds, output a message with the names of the surviving pigs(ordered by their order of input). For example,Time 33: No more birds. The pigs win!Remaining pigs:PorkyBrickand stop the game.The logic of this is a bit complicated, with a number of cases to check, so implement it carefully!Use of Classes and FunctionsYou must use at least three classes, one for a pig, one for a bird, and one for a barrier. The pigclass is the smallest and can be as simple as:class Pig(object):def __init__( self, n, x0, y0, r0 ):self.name = nself.x = x0self.y = y0self.radius = r0although we added other functionality to our code to make some of the reporting and printingeasier. You are welcome to use this part of the pig de nition in your code. We will not consider itin our code comparison. The barriers and birds are increasingly more complicated and we suggestthat in particular you add a lot of functionality into the Bird class to make the simulation easier.Test CasesThis is the longest and one of the most complicated assignments we have given so far. The programmatch portion (autograding) will be worth 110 of the 140 points available for the homework, andwe want you to have an opportunity to get substantial parital credit even if you are having troublecompleting all three classes correctly. To achieve this, we will be providing you with four scenariosof varying diculty: Scenario 1 (example scenario1.json) will be worth 20 points. The scenario will include birdsand barriers, but no pigs and should terminate immediately after reporting the le contentswithout executing the simulation loop at all and without having to move the birds.5 Scenario 2 (example scenario1.json) will be worth 30 points and will not include anycollisions. You will need to read in and report on the birds, pigs and barriers, but whenthe simulation starts the birds will y without hitting anything to the end of the board.Obviously, the pigs will win. Scenario 3 (example scenario3.json), worth 35 points, will add collisions between birds andpigs, but not striking of barriers by birds. Scenario 4 (example scenario4.json), worth 25 points, will also include birds striking bar-riers.Thus, if you just implement the code for scenarios 1 and 2 you can earn up to 45% of the autogradepoints. Adding in collisions with pigs can get you all the way up to 77% of the autograded points.Two important notes:1. Some of the tests we use on Submitty will be dierent from these example les.2. Do not ask for help on a later scenario until you can prove that your code works for anearlier scenario. In other words, get Scenario 1 working before you even consider moving onto Scenario 2, and get Scenario 2 working before you even consider Scenario 3Module Organization and Submission InstructionsPlease follow these instructions carefully: Your program should be split across four les,Pig.py, Bird.py, Barrier.py and hw7.py. hw7.py should start withfrom Pig import *from Bird import *from Barrier import *and include the rest of your code. All code should follow our coding guidelines. If you need arefresher, look at HW6.We recommend that when you program your solution you start simple and build up:1. Create the three class les, Bird.py, Pig.py, and Barrier.py les and write initializers forthem.2. Write the code to ask for the lename, create the lists, and report on the initial list contents.3. Test against the rst scenario to make sure your input is working correctly. At this point youhave earned 20 of 110 points.4. Add ying to the bird and write the simulation loop without worrying about collisions5. Test and verify that you correctly solve the second scenario. At this point you haveearned 50 of the 110 autograding points. Save this le as a backup.6. Without breaking scenario 2, add in code to let birds collide with pigs.7. Test and verify that you correctly solve the rst and second scenarios. At this point youhave earned 85 of the 110 autograding points. Save this le as a backup.8. Without breaking scenario 3, add in code to let birds collide with barriers.9. Test and verify that you correctly solve the rst, second and third scenarios. At this pointyou have earned 110 of the 110 autograding points. Save this le as a backup.The output from the scenarios and the scenario input les can all be found in hw07files.zip. Inorder to submit your solution: You will need to submit your homework by dragging all four ofthe les Bird.py, Pig.py, Barrier.py and hw7.py into the Submitty submission block. Be carefulto name them correctly.6