;; world_template.scm                         Daniel Azus                         12-4-2006

;; This program uses the world teachpack

;; This is a template for a program that uses the world teachpack that can use the mouse and keyboard
;; All default values are defined at the top of the program

;; Constants
(define WindowWidth 800)            ;; The width of the window in pixels
(define WindowHeight 640)           ;; The height of the window in pixels
(define FrameRate 30)               ;; The target rate the window is updated per second (frames per second)
(define FrameDelay (/ 1 FrameRate)) ;; The delay between frames, based on the frame rate

;; Constants
;; Default values for variables
(define InitFrame 0)
(define InitGameOver false)
(define InitPaused false)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Defining and setting the default world

;; Defining the world
;; World variables
;; Frame = Frames since the program started
;; GameOver = True if the player has lost the game
;; Paused = If the world is paused
(define-struct World [Frame GameOver Paused])

;; The first world that starts with the default values
(define InitialWorld (make-World InitFrame InitGameOver InitPaused))

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Drawing helper functions

;; Used when drawing images in a world
(define (PutImage image x y image2)
  (place-image image (+ x (/ (image-width image) 2)) (+ y (/ (image-height image) 2)) image2)
)

;; Used when drawing images in a world with out offset
(define (PutImageNorm image x y image2)
  (place-image image x y image2)
)

;; Used when drawing text in a world
(define (PutText Text TextColor x y image2)
  (PutImageNorm (text Text 12 TextColor) x y image2)
)

;; Used when drawing text in a world with a font size
(define (PutTextSized Text TextColor fontsize x y image2)
  (PutImageNorm (text Text fontsize TextColor) x y image2)
)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Everything that has to do with drawing

;; Constant drawing colors
(define ColorWhite (make-color 0 0 0))
(define ColorBlack (make-color 0 0 0))
(define ColorRed (make-color 255 0 0))
(define ColorGreen (make-color 0 255 0))
(define ColorBlue (make-color 0 0 255))
(define ColorDarkGrey (make-color 100 100 100))

;; Constants for drawing
(define Background (rectangle WindowWidth WindowHeight 'solid ColorDarkGrey))

;; This draws the game in action
(define (DrawGame aworld)
  (PutTextSized (number->string (World-Frame aworld)) ColorWhite 18 (/ WindowWidth 2) 0
  (PutImage Background 0 0
  (empty-scene WindowWidth WindowHeight)
  ))
)

;; This takes care of making sure everything gets drawn
(define (Draw-Window aworld)
  (cond
    [(World-GameOver aworld)
      (PutTextSized "GAME OVER" ColorBlue 50 (/ WindowWidth 4) (/ WindowHeight 4)
      (PutTextSized "Press 'n' to restart" ColorBlue 16 (+ (/ WindowWidth 4) 100) (- (/ WindowHeight 2) 50)
      (DrawGame aworld)))
    ]
    [(World-Paused aworld)
      (PutTextSized "PAUSED" ColorBlue 50 (+ (/ WindowWidth 4) 50) (/ WindowHeight 4)
      (DrawGame aworld))
    ]
    [else (DrawGame aworld)]
  )
)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Everything that has to do with updating

;; Takes care of updating all the world variables of the current world
(define (UpdateWorld aworld)
  (cond
    [(World-Paused aworld) aworld] ;; Check if this world is paused
    [else
      (make-World
        (+ (World-Frame aworld) 1) ;; Increment the frame count
        (World-GameOver aworld) ;; Game over
        false ;; This code will not be reached if the world is paused, so it is ok to use a constant value.
      )
    ]
  )
)

;; This takes care of making sure everything gets updated
(define (Update aworld)
  (cond
    [(World-Paused aworld) aworld] ; If world is paused nothing changes
    [else (UpdateWorld aworld)]
  )
)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Everything that has to do with mouse input

;; This is called when a mouse button is pressed.
;; It is unable to tell which button.
(define (Mouse-Button-Down x y aworld)
  aworld
)

;; This is called when a mouse button is released.
;; It is unable to tell which button.
(define (Mouse-Button-Released x y aworld)
  aworld
)

;; This is called when the mouse is moved.
;; It is unable to tell which button.
(define (Mouse-Move x y aworld)
  aworld
)

;; This is called when the mouse is dragged.
;; It is unable to tell which button.
(define (Mouse-Drag x y aworld)
  aworld
)

;; This is called anytime the mouse changes.
;; It is unable to tell which button is pressed or released.
(define (Handle-Mouse a b c d)
  (cond
    [(eqv? d 'button-down) (Mouse-Button-Down b c a)]
    [(eqv? d 'button-up) (Mouse-Button-Released b c a)]
    [(eqv? d 'drag) (Mouse-Drag b c a)]
    [(eqv? d 'move) (Mouse-Move b c a)]
    [else a]
  )
)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Everything that has to do with keyboard input

;; The up arrow key was pressed
(define (Key-UpArrow aworld)
  aworld
)

;; The down arrow key was pressed
(define (Key-DownArrow aworld)
  aworld
)

;; The W key was pressed
(define (Key-w aworld)
  aworld
)

;; The S key was pressed
(define (Key-s aworld)
  aworld
)

;; The S key was pressed
(define (Key-n aworld)
  (if (World-GameOver aworld)
    InitialWorld
    aworld
  )
)

;; This is called anytime a key to pressed or released.
;; It is unable to tell if a key is still pressed or which key was released.
;; If a key is held down then the function will get called multiple times.
(define (Handle-Keys a b)
  (cond
    [(eqv? b 'up) (Key-UpArrow a)]
    [(eqv? b 'down) (Key-DownArrow a)]
    [(eqv? b #\w) (Key-w a)]
    [(eqv? b #\s) (Key-s a)]
    [(eqv? b #\n) (Key-n a)]
    [else a]
  )
)

;; =====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*=====*
;; Sets up the window and what functions to call and when they should be called

;; Creates the window
(big-bang WindowWidth WindowHeight FrameDelay InitialWorld)

;; Set the drawing function
(on-redraw Draw-Window)

;; Set the updating function
(on-tick-event Update)

;; Set the key press function
(on-key-event Handle-Keys)

;; Set the mouse handler function
(on-mouse-event Handle-Mouse)