1+ (ns schlang.core
2+ (:require [play-cljs.core :as p]))
3+
4+ (enable-console-print! )
5+
6+ (declare menu-screen main-screen )
7+
8+ (def initial-state (let [x 12
9+ y 12
10+ x2 (int (/ x 2 ))]
11+ {:width 500
12+ :height 500
13+ :speed 400
14+ :game {:width x
15+ :height y
16+ :score 0
17+ :food [[x2 1 ]]}
18+ :snake {:body [[x2 (-> y dec dec dec)]
19+ [x2 (-> y dec dec)]
20+ [x2 (-> y dec)]]
21+ :eaten false }
22+ :player {:key-pressed :none
23+ :direction :up }}))
24+
25+ (defonce *state (atom initial-state))
26+
27+ (defonce game (let [width (:width @*state)
28+ height (:height @*state)]
29+ (p/create-game width height)))
30+
31+ (defn next-direction [direction key-pressed]
32+ (let [ctrl {:right {:up :right
33+ :right :down
34+ :down :left
35+ :left :up }
36+ :left {:up :left
37+ :left :down
38+ :down :right
39+ :right :up }}]
40+ (if (#{:up :right :down :left } key-pressed)
41+ (-> ctrl key-pressed direction)
42+ direction)))
43+
44+ (defn next-position [[x y] direction]
45+ (let [state @*state
46+ width (-> state :game :width )
47+ height (-> state :game :height )
48+ assumed-position (case direction
49+ :up [x (dec y)]
50+ :down [x (inc y)]
51+ :left [(dec x) y]
52+ :right [(inc x) y])
53+ position-checked-x (let [[new-x new-y] assumed-position]
54+ (cond (>= new-x width) [0 new-y]
55+ (< new-x 0 ) [(dec width) new-y]
56+ :default assumed-position))
57+ position-checked-y (let [[new-x new-y] position-checked-x]
58+ (cond (>= new-y height) [new-x 0 ]
59+ (< new-y 0 ) [new-x (dec height)]
60+ :default position-checked-x))]
61+ position-checked-y))
62+
63+ #_(events/listen js/window " mousedown" fn []))
64+
65+ (defn new-food [s]
66+ (let [width (-> s :game :width )
67+ height (-> s :game :height )
68+ points (repeatedly (fn [] [(rand-int width) (rand-int height)]))
69+ occupied (reduce into #{} [(-> s :game :food ) (-> s :snake :body )])]
70+ (some #(if (not (occupied %))
71+ %)
72+ points)))
73+
74+ (defn check-food [s]
75+ (let [food (into #{} (-> s :game :food ))
76+ body (-> s :snake :body )
77+ head (first body)
78+ eat (food head)]
79+ (if eat
80+ (-> s
81+ (update-in [:game :food ] (fn [food] (remove #(= % head) food)))
82+ (update-in [:game :food ] #(conj % (new-food s)))
83+ (assoc-in [:snake :eaten ] true ))
84+ s)))
85+
86+ (defn step []
87+ (let [state @*state
88+ old-direction (-> state :player :direction )
89+ key-pressed (-> state :player :key-pressed )
90+ new-direction (next-direction old-direction key-pressed)
91+ old-body (-> state :snake :body )
92+ old-head (first old-body)
93+ new-head (next-position old-head new-direction)
94+ eaten (-> state :snake :eaten )
95+ new-body (into [new-head] (if eaten
96+ old-body
97+ (drop-last old-body)))
98+ lost (not (apply distinct? new-body))]
99+ (if lost
100+ (p/set-screen game menu-screen)
101+ (swap! *state
102+ (fn [state]
103+ (if lost
104+ initial-state
105+ (-> state
106+ (assoc-in [:snake :body ] new-body)
107+ (assoc-in [:player :direction ] new-direction)
108+ (assoc-in [:snake :eaten ] false )
109+ (assoc-in [:player :key-pressed ] :move-executed )
110+ check-food)))))))
111+
112+ ; define a screen, where all the action takes place
113+ (def main-screen
114+ (reify p/Screen
115+
116+ ; runs when the screen is first shown
117+ (on-show [this]
118+ (reset! *state initial-state)
119+ (swap! *state (fn [s]
120+ (-> s
121+ (update-in [:timeoutid ]
122+ (fn [_]
123+ (js/setInterval
124+ step
125+ (:speed s))))))))
126+
127+ ; runs when the screen is hidden
128+ (on-hide [this]
129+ (js/clearInterval (:timeoutid @*state)))
130+
131+ ; runs every time a frame must be drawn (about 60 times per sec)
132+ (on-render [this]
133+ (p/render game
134+ (let [state @*state
135+ width (:width state)
136+ height (:height state)
137+ game-width (-> state :game :width )
138+ game-height (-> state :game :height )
139+ tile-width (/ width game-width)
140+ tile-height (/ height game-height)
141+ body (-> state :snake :body )
142+ part-of-body (into #{} body)
143+ food (into #{} (-> state :game :food ))]
144+ [[:stroke {:color " gray"
145+ (for [x (range game-width) y (range game-height)]
146+ [:fill {:color (cond (= [x y] (first body)) " darkgray"
147+ (part-of-body [x y]) " gray"
148+ (food [x y]) " lightgreen"
149+ :default " lightblue"
150+ [:rect {:x (* x tile-width)
151+ :y (* y tile-height)
152+ :width tile-width
153+ :height tile-height}
154+ (cond (= [x y] (first body))
155+ (let [old-direction (-> state :player :direction )
156+ key-pressed (-> state :player :key-pressed )
157+ new-direction (next-direction old-direction key-pressed)
158+ eye-width (/ tile-width 4 )
159+ eye-height (/ tile-width 4 )]
160+ [:fill {:color " red"
161+ [:rect {:x (case new-direction
162+ :left 0
163+ :right (- tile-width eye-width)
164+ (- (/ tile-width 4 ) (/ eye-width 2 )))
165+ :y (case new-direction
166+ :up 0
167+ :down (- tile-height eye-height)
168+ (- (/ tile-height 4 ) (/ eye-height 2 )))
169+ :height eye-height
170+ :width eye-width}]
171+ [:rect {:x (case new-direction
172+ :left 0
173+ :right (- tile-width eye-width)
174+ (- (* 3 (/ tile-width 4 )) (/ eye-width 2 )))
175+ :y (case new-direction
176+ :up 0
177+ :down (- tile-height eye-height)
178+ (- (* 3 (/ tile-height 4 )) (/ eye-height 2 )))
179+ :height eye-height
180+ :width eye-width}]])
181+ (food [x y])
182+ (let [eye-width (/ tile-width 4 )
183+ eye-height (/ tile-width 4 )]
184+ [:fill {:color " green"
185+ [:rect {:x (+ (- (/ tile-width 4 ) (/ eye-width 2 ))
186+ (* (rand ) (/ eye-width 4 )))
187+ :y (+ (- (/ tile-height 4 ) (/ eye-height 2 ))
188+ (* (rand ) (/ eye-width 4 )))
189+ :height eye-height
190+ :width eye-width}]
191+ [:rect {:x (+ (- (* 3 (/ tile-width 4 )) (/ eye-width 2 ))
192+ (* (rand ) (/ eye-width 4 )))
193+ :y (+ (- (/ tile-height 4 ) (/ eye-height 2 ))
194+ (* (rand ) (/ eye-height 4 )))
195+ :height eye-height
196+ :width eye-width}]]))]])]]))
197+ (let [old-key (-> @*state :player :key-pressed )
198+ pressed-keys (p/get-pressed-keys game)]
199+ (swap! *state (fn [s]
200+ (cond (= old-key :move-executed ) (if (empty? pressed-keys)
201+ (assoc-in s [:player :key-pressed ] :none )
202+ s)
203+ (empty? pressed-keys) s
204+ ; (pressed-keys 87) (update :text-y dec) ;up
205+ (= pressed-keys #{68 }) (assoc-in s [:player :key-pressed ] :right )
206+ ; (pressed-keys 83) (update :text-y inc) ;down
207+ (= pressed-keys #{65 }) (assoc-in s [:player :key-pressed ] :left )
208+ :default (assoc-in s [:player :key-pressed ] :none ))))))))
209+
210+ #_(if (= (first body) [x y])
211+ (let [direction (-> state :player :direction )]
212+ [:fill {:color " red"
213+ [:rect {:x (+ (* x tile-width)
214+ (/ tile-width 3 ))
215+ :y (+ (* y tile-height)
216+ (/ tile-height 3 ))
217+ :width tile-width
218+ :height tile-height}]]))
219+
220+ #_[:fill {:color " black"
221+ [:text {:value (str " Hello, world!" p/get-pressed-keys game))
222+ :x (:text-x state)
223+ :y (:text-y state)
224+ :size 16
225+ :font " Georgia"
226+ :style :italic }]]
227+
228+ (def menu-screen
229+ (reify p/Screen
230+
231+ ; runs when the screen is first shown
232+ (on-show [this])
233+
234+ ; runs when the screen is hidden
235+ (on-hide [this])
236+
237+ ; runs every time a frame must be drawn (about 60 times per sec)
238+ (on-render [this]
239+ (p/render game
240+ [[:fill {:color " lightblue"
241+ [:rect {:x 0 :y 0 :width 500 :height 500 }]]
242+ [:fill {:color " black"
243+ [:text {:value (str " press any button to start!"
244+ :x (/ (:width @*state) 4 )
245+ :y (/ (:height @*state) 2 )
246+ :size 16
247+ :font " Georgia"
248+ :style :italic }]]])
249+ (let [pressed-keys (p/get-pressed-keys game)]
250+ (if (empty? pressed-keys)
251+ nil
252+ (p/set-screen game main-screen))))))
253+
254+
255+ ; start the game
256+ (comment
257+ (doto game
258+ (p/start )
259+ (p/set-screen menu-screen)))
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