ITEC 380 2016fall ibarland

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hw-ec-game-structs
Kong I
data design

Extra credit; due Oct.27 15:00Nov.06 23:59.

For hw06, you will be writing some list-processing functions for the Kong game. I will provide code that does most of the non-list processing (including most of the program-design). However, if you want to have the pride of writing the entire game yourself, you may do this extra-credit homework.

All problems require following the design recipe.

• Create a racket struct for each of: a player, a platform, a barrel, and ladder.

  (When making examples-of-the-data for each struct, you might want to think about examples which will also be useful for writing test cases below.)

  (Even if some of these have fields in common, we will not use inheritance to factor that out. If you want to though, you can (require "student-extras.rkt"); if you look in side that file you'll see some examples.)

• For those struct-types that will be updated during the game (T = player, barrel), write a function update-T which updates the object given the fact that one tick of time has passed (one frame). These will ignore any outside-objects (like platforms or ladders); we'll write a later method which handles interaction between objects.

  Of course, these functions will return new objects (no changing/mutating fields). Happily, test-cases are made easier by copy/pasting your existing examples-of-data, and code made easier by copy/pasting your template. You might realize you need additional examples-of-data to test certain circumstances.

• For those struct-types that care about key-presses (T = player), write a function X-handle-key which takes in an T and a keypress, and returns a new, suitably-modified T.

  Library:To get access to functions like key=?, you need to (require 2htdp/universe).

  Keypresses do not correspond to any time passing, so a keypress will (presumably) not move the T in any way.

• Write functions player-handle-platform, barrel-handle-platform, and player-handle-ladder, which returns a player (or barrel) and resolves any adjustments due to the other object.

  For example player-handle-platform: if a player has been jumping/falling, and is now located inside a platform, this function would move the player so that it is exactly on top of the platform, and no longer falling-jumping.

• Finally — least important — viewing the model: For each struct T (besides the world struct), write a function draw-T which takes in one object and any background-image, and returns the object drawn on that background.

  Library:I recommend using place-image; this function crops the result to the background.

hw06 will take my solution to (most of) these tasks, and have you provide versions which work for lists of platforms, ladders, and barrels.

All the above should have their tests, as well as signatures and (brief) purpose statements. Only after all tests pass, the following should work (in racket):

(require 2htdp/universe)

(big-bang some-initial-world
          [on-key  world-handle-key]
          [on-tick update-world]
          [to-draw draw-world])

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©2016, Ian Barland, Radford University Last modified 2016.Oct.27 (Thu)

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