summaryrefslogtreecommitdiff
path: root/heyllama.scm
blob: 6a71a0dfd2947fcd65a9713a131f9a9686363bce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
(use-modules (chickadee)
             (chickadee math vector)
             (chickadee math rect)
             (chickadee math grid)
             (chickadee render font)
             (chickadee render sprite)
             (chickadee render texture)
             (chickadee render tiled)
             (chickadee render color)
             (chickadee render shapes)
             (oop goops))

(define-class <animal> (<object>)
  (pos #:init-keyword #:pos
       #:getter get-pos)

  (size #:init-keyword #:size
        #:getter get-size)

  (draw-offset #:init-keyword #:draw-offset
               #:getter get-draw-offset)

  (y-vel #:init-value 0.0
       #:getter get-y-vel
       #:setter set-y-vel!)

  (face-direction
   #:init-keyword #:face-dir
   #:setter set-face-direction!
   #:getter get-face-direction)

  (animation-step #:init-value 0
                  #:getter get-animation-step
                  #:setter set-animation-step!)

  (sprite #:init-keyword #:sprite
          #:getter get-sprite))


(define (draw-animal animal)

  (define (face-row dir)
    (if (> 0 dir) 4 12))

  (draw-sprite (texture-atlas-ref (get-sprite animal)
                                  (+ (face-row (get-face-direction animal))
                                     (truncate (/ (get-animation-step animal) 4))))
               (vec2- (get-screen-pos animal)
                      (get-draw-offset animal))))


;; -------------- Initial game state --------------

(define llama #f)
(define tile-map #f)
(define view-pos #v(0.0 0.0))
(define grid (make-grid 16))
(define show-hitboxes #f)

(define (load)
  (set! llama (make <animal>
                #:pos #v(200.0 200.0)
                #:size #v(128.0 128.0)
                #:draw-offset #v(15 12)
                #:face-dir 1
                #:sprite (split-texture (load-image "llama_walk.png")
                                        80 80
                                        #:spacing 48
                                        #:margin 24)))

  (grid-add grid 'llama 200.0 200.0 50.0 64.0)

  (set! tile-map (load-tile-map "llama.tmx"))

  ;; Add objects from map to grid

  (define (add-to-grid obj)
    (let ((shape (map-object-shape obj)))
      (grid-add grid
                (map-object-id obj)
                (rect-x shape)
                (- (rect-y shape) (rect-height shape))
                (rect-width shape)
                (rect-height shape))))


  (let ((objects (object-layer-objects
                  (vector-ref (tile-map-layers tile-map)
                              1))))
    (for-each (lambda (obj)
                (add-to-grid obj))
              objects)))



;; ------------------------------------------------

(define (draw alpha)

  (draw-tile-map tile-map
                 #:position (vec2* view-pos -1.0))

  (draw-animal llama)

  (when show-hitboxes
    (let ((col (make-color 0.0 0.0 0.7 0.8)))
      (for-each-item (lambda (item rect)
                       (draw-filled-rect (rect-move-by-vec2 rect
                                                            (vec2* view-pos -1))
                                         col))
                     grid))))


(define (get-screen-pos animal)
  (vec2- (get-pos animal) view-pos))


(define (rect-xy rect)
  #v((rect-x rect) (rect-y rect)))


(define (get-screen-rect animal)
  (let ((screen-pos (get-screen-pos animal)))
    (make-rect (vec2-x screen-pos)
               (vec2-y screen-pos)
               (vec2-x (get-size animal))
               (vec2-y (get-size animal)))))


(define (overshoot small-rect big-rect)
  (let ((moved-small-rect (rect-clamp small-rect big-rect)))
    (vec2- (rect-xy small-rect)
           (rect-xy moved-small-rect))))


(define (update tstep)

  (let ((x-vel 0.0))

    (define (slide-llama-only a b)
       (if (eq? a 'llama) slide #f))

    (when (key-pressed? 'right)
      (set-face-direction! llama 1)
      (set! x-vel 1.0)
      (set-animation-step! llama
                           (floor-remainder
                            (+ (get-animation-step llama) -1)
                            16)))

    (when (key-pressed? 'left)
      (set-face-direction! llama -1)
      (set! x-vel -1.0)
      (set-animation-step! llama
                           (floor-remainder
                            (- (get-animation-step llama) 1)
                            16)))

    (vec2-add! (get-pos llama)
               #v((* x-vel tstep 0.2) 0.0))

    (grid-move grid
               'llama
               (get-pos llama)
               slide-llama-only))

  ;; Gravity
  (define (slide-llama-only-and-zero-yvel a b)
    (if (eq? a 'llama)
        (lambda (item item-rect other other-rect goal)
          (set-y-vel! llama 0.0)
          (slide item item-rect other other-rect goal))
        #f))

  (set-y-vel! llama
              (- (get-y-vel llama) 0.4))

  (vec2-add! (get-pos llama)
             #v(0.0 (get-y-vel llama)))

  (grid-move grid
             'llama
             (get-pos llama)
             slide-llama-only-and-zero-yvel)

  ;; Ensure llama is near centre of screen
  (let ((fovea (make-rect 150.0 150.0 350.0 350.0))
        (llama-rect (get-screen-rect llama)))
    (unless (rect-within? llama-rect fovea)
      (vec2-add! view-pos (overshoot llama-rect fovea)))))


(define (key-press key scancode modifier repeat?)
  (case key
    ((q) (abort-game))
    ((f1) (set! show-hitboxes (not show-hitboxes)))
    ((space) (unless repeat?
               (set-y-vel! llama 8.0)))))


(run-game #:window-title "Hey Llama!"
          #:load load
          #:draw draw
          #:key-press key-press
          #:update-hz 60
          #:update update)