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- Committer: Josh C
- Date: 2013-04-27 16:36:06 UTC
- Revision ID: josh@9ix.org-20130427163606-0eef0f5v9wbzoi0j
zoetrope 1.4
- files added:
- zoetrope
- zoetrope/core
- zoetrope/input
- zoetrope/sprites
- zoetrope/ui
- zoetrope/utils
added
removed
zoetrope/core/group.lua
1
-- Class: Group
2
-- A group is a set of sprites. Groups can be used to
3
-- implement layers or keep categories of sprites together.
4
--
5
-- Extends:
6
-- <Class>
7
--
8
-- Event: onUpdate
9
-- Called once each frame, with the elapsed time since the last frame in seconds.
10
--
11
-- Event: onBeginFrame
12
-- Called once each frame like onUpdate, but guaranteed to fire before any others' onUpdate handlers.
13
--
14
-- Event: onEndFrame
15
-- Called once each frame like onUpdate, but guaranteed to fire after all others' onUpdate handlers.
16
17
Group = Class:extend
18
{
19
-- Property: active
20
-- If false, none of its member sprites will receive update-related events.
21
active = true,
22
23
-- Property: visible
24
-- If false, none of its member sprites will be drawn.
25
visible = true,
26
27
-- Property: solid
28
-- If false, nothing will collide against this group, nor will this group
29
-- displace any other sprite. This does not prevent collision checking
30
-- against individual sprites in this group, however.
31
solid = true,
32
33
-- Property: sprites
34
-- A table of member sprites, in drawing order.
35
sprites = {},
36
37
-- Property: timeScale
38
-- Multiplier for elapsed time; 1.0 is normal, 0 is completely frozen.
39
timeScale = 1,
40
41
-- Property: translate
42
-- This table's x and y properties shift member sprites' positions when drawn.
43
-- To draw sprites at their normal position, set both x and y to 0.
44
translate = { x = 0, y = 0 },
45
46
-- Property: translateScale
47
-- This table's x and y properties multiply member sprites'
48
-- positions, which you can use to simulate parallax scrolling. To draw
49
-- sprites at their normal position, set both x and y to 1.
50
translateScale = { x = 1, y = 1 },
51
52
-- Method: add
53
-- Adds a sprite to the group.
54
--
55
-- Arguments:
56
-- sprite - <Sprite> to add
57
--
58
-- Returns:
59
-- nothing
60
61
add = function (self, sprite)
62
assert(sprite, 'asked to add nil to a group')
63
assert(sprite ~= self, "can't add a group to itself")
64
65
if STRICT and self:contains(sprite) then
66
local info = debug.getinfo(2, 'Sl')
67
print('Warning: adding a sprite to a group it already belongs to (' ..
68
info.short_src .. ' line ' .. info.currentline .. ')')
69
end
70
71
table.insert(self.sprites, sprite)
72
end,
73
74
-- Method: remove
75
-- Removes a sprite from the group. If the sprite is
76
-- not in the group, this does nothing.
77
--
78
-- Arguments:
79
-- sprite - <Sprite> to remove
80
--
81
-- Returns:
82
-- nothing
83
84
remove = function (self, sprite)
85
for i, spr in ipairs(self.sprites) do
86
if spr == sprite then
87
table.remove(self.sprites, i)
88
return
89
end
90
end
91
92
if STRICT then
93
local info = debug.getinfo(2, 'Sl')
94
print('Warning: asked to remove a sprite from a group it was not a member of (' ..
95
info.short_src .. ' line ' .. info.currentline .. ')')
96
end
97
end,
98
99
-- Method: moveToFront
100
-- Moves a sprite in the group so that it is drawn on top
101
-- of all other sprites in the group.
102
--
103
-- Arguments:
104
-- sprite - <Sprite> to move, should already be a member of the group
105
--
106
-- Returns:
107
-- nothing
108
109
moveToFront = function (self, sprite)
110
for i, spr in ipairs(self.sprites) do
111
if spr == sprite then
112
table.remove(self.sprites, i)
113
table.insert(self.sprites, sprite)
114
return
115
end
116
end
117
118
if STRICT then
119
print('Warning: asked to move sprite to front of group, but is not a member: ' .. sprite)
120
end
121
end,
122
123
-- Method: moveToBack
124
-- Moves a sprite in the group so that it is drawn below
125
-- all other sprites in the group.
126
--
127
-- Arguments:
128
-- sprite - <Sprite> to move, should already be a member of the group
129
--
130
-- Returns:
131
-- nothing
132
133
moveToBack = function (self, sprite)
134
for i, spr in ipairs(self.sprites) do
135
if spr == sprite then
136
table.remove(self.sprites, i)
137
table.insert(self.sprites, 1, sprite)
138
return
139
end
140
end
141
142
if STRICT then
143
print('Asked to move sprite to back of group, but is not a member: ' .. sprite)
144
end
145
end,
146
147
-- Method: sort
148
-- Sorts members into a new draw sequence.
149
--
150
-- Arguments:
151
-- func - function to perform the sort. This will receive two <Sprite>s as arguments;
152
-- the function must return whether the first should be drawn below the second.
153
--
154
-- Returns:
155
-- nothing
156
157
sort = function (self, func)
158
table.sort(self.sprites, func)
159
end,
160
161
-- Method: collide
162
-- Collides all solid sprites in the group with another sprite or group.
163
-- This calls the <Sprite.onCollide> event handlers on all sprites that
164
-- collide with the same arguments <Sprite.collide> does.
165
--
166
-- It's often useful to collide a group with itself, e.g. myGroup:collide().
167
-- This checks for collisions between the sprites that make up the group.
168
--
169
-- Arguments:
170
-- ... - any number of <Sprite>s or <Group>s to collide with. If none
171
-- are specified, the group collides with itself.
172
--
173
-- Returns:
174
-- nothing
175
--
176
-- See Also:
177
-- <Sprite.collide>
178
179
collide = function (self, ...)
180
local list = {...}
181
182
if #list > 0 then
183
if STRICT then
184
for _, other in pairs(list) do
185
assert(other:instanceOf(Group) or other:instanceOf(Sprite), 'asked to collide non-group/sprite ' ..
186
type(other))
187
end
188
end
189
190
Collision:check(self, ...)
191
else
192
Collision:check(self, self)
193
end
194
end,
195
196
-- Method: setEffect
197
-- Sets a pixel effect to use while drawing sprites in this group.
198
-- See https://love2d.org/wiki/PixelEffect for details on how pixel
199
-- effects work. After this call, the group's effect property will be
200
-- set up so you can send variables to it. Only one pixel effect can
201
-- be active on a group at a time.
202
--
203
-- Arguments:
204
-- filename - filename of effect source code; if nil, this
205
-- clears any existing pixel effect.
206
-- effectType - either 'screen' (applies the effect to the entire
207
-- group once, via an offscreen canvas), or 'sprite'
208
-- (applies to the effect to each individual draw operation).
209
-- Screen effects use more resources, but certain effects
210
-- need to work on the entire screen to be effective.
211
--
212
-- Returns:
213
-- whether the effect was successfully created
214
215
setEffect = function (self, filename, effectType)
216
effectType = effectType or 'screen'
217
218
if love.graphics.isSupported('pixeleffect') and
219
(effectType == 'sprite' or love.graphics.isSupported('canvas'))then
220
if filename then
221
self.effect = love.graphics.newPixelEffect(Cached:text(filename))
222
self.effectType = effectType
223
else
224
self.effect = nil
225
end
226
227
return true
228
else
229
return false
230
end
231
end,
232
233
-- Method: count
234
-- Counts how many sprites are in this group.
235
--
236
-- Arguments:
237
-- subgroups - include subgroups?
238
--
239
-- Returns:
240
-- integer count
241
242
count = function (self, subgroups)
243
if subgroups then
244
local count = 0
245
246
for _, spr in pairs(self.sprites) do
247
if spr:instanceOf(Group) then
248
count = count + spr:count(true)
249
else
250
count = count + 1
251
end
252
end
253
254
return count
255
else
256
return #self.sprites
257
end
258
end,
259
260
-- Method: die
261
-- Makes the group totally inert. It will not receive
262
-- update events, draw anything, or be collided.
263
--
264
-- Arguments:
265
-- none
266
--
267
-- Returns:
268
-- nothing
269
270
die = function (self)
271
self.active = false
272
self.visible = false
273
self.solid = false
274
end,
275
276
-- Method: revive
277
-- Makes this group completely active. It will receive
278
-- update events, draw itself, and be collided.
279
--
280
-- Arguments:
281
-- none
282
--
283
-- Returns:
284
-- nothing
285
286
revive = function (self)
287
self.active = true
288
self.visible = true
289
self.solid = true
290
end,
291
292
-- Method: contains
293
-- Returns whether this group contains a sprite.
294
--
295
-- Arguments:
296
-- sprite - sprite to look for
297
-- recurse - check subgroups? defaults to true
298
--
299
-- Returns:
300
-- boolean
301
302
contains = function (self, sprite, recurse)
303
if recurse ~= false then recurse = true end
304
305
for _, spr in pairs(self.sprites) do
306
if spr == sprite then return true end
307
308
if recurse and spr:instanceOf(Group) and spr:contains(sprite) then
309
return true
310
end
311
end
312
313
return false
314
end,
315
316
-- Method: loadLayers
317
-- Loads layers from a Lua source file (as generated by Tiled -- http://mapeditor.org).
318
-- Each layer is created as a <Group> belonging to this one and added to preserve its
319
-- ordering. Tile layers are created as <Map> instances; object layers will try to create
320
-- instances of a class named by the object's name property. If no class exists by
321
-- this name, or the object has no name property, a gray fill will be created instead,
322
-- as a placeholder. If the object has a property named _the, then this will set
323
-- the.[whatever] to it.
324
--
325
-- Arguments:
326
-- file - filename to load
327
-- tileClass - class to create tiles in tile layers with; constructor
328
-- will be called with properties: image, width,
329
-- height, imageOffset (with x and y sub-properties)
330
--
331
-- Returns:
332
-- nothing
333
334
loadLayers = function (self, file, tileClass)
335
local ok, data = pcall(loadstring(Cached:text(file)))
336
local _, _, directory = string.find(file, '^(.*[/\\])')
337
directory = directory or ''
338
339
if ok then
340
-- store tile properties by gid
341
342
local tileProtos = {}
343
344
for _, tileset in pairs(data.tilesets) do
345
for _, tile in pairs(tileset.tiles) do
346
local id = tileset.firstgid + tile.id
347
348
for key, value in pairs(tile.properties) do
349
tile.properties[key] = tovalue(value)
350
end
351
352
tileProtos[id] = tile
353
tileProtos[id].width = tileset.tilewidth
354
tileProtos[id].height = tileset.tileheight
355
end
356
end
357
358
for _, layer in pairs(data.layers) do
359
if self.prototype[layer.name] then
360
error('The class you are loading layers into reserves the ' .. layer.name .. ' property for its own use; you cannot load a layer with that name')
361
end
362
363
if STRICT and self[layer.name] then
364
local info = debug.getinfo(2, 'Sl')
365
print('Warning: a property named ' .. layer.name .. ' already exists in this group (' ..
366
info.short_src .. ', line ' .. info.currentline .. ')')
367
end
368
369
if layer.type == 'tilelayer' then
370
local map = Map:new{ spriteWidth = data.tilewidth, spriteHeight = data.tileheight }
371
map:empty(layer.width, layer.height)
372
373
-- load tiles
374
375
for _, tiles in pairs(data.tilesets) do
376
map:loadTiles(directory .. tiles.image, tileClass or Tile, tiles.firstgid)
377
378
-- and mix in properties where applicable
379
380
for id, tile in pairs(tileProtos) do
381
if map.sprites[id] then
382
map.sprites[id]:mixin(tile.properties)
383
end
384
end
385
end
386
387
-- load tile data
388
389
local x = 1
390
local y = 1
391
392
for _, val in ipairs(layer.data) do
393
map.map[x][y] = val
394
x = x + 1
395
396
if x > layer.width then
397
x = 1
398
y = y + 1
399
end
400
end
401
402
self[layer.name] = map
403
self:add(map)
404
elseif layer.type == 'objectgroup' then
405
local group = Group:new()
406
407
for _, obj in pairs(layer.objects) do
408
-- roll in tile properties if based on a tile
409
410
if obj.gid and tileProtos[obj.gid] then
411
local tile = tileProtos[obj.gid]
412
413
obj.name = tile.properties.name
414
obj.width = tile.width
415
obj.height = tile.height
416
417
for key, value in pairs(tile.properties) do
418
obj.properties[key] = tovalue(value)
419
end
420
421
-- Tiled tile-based objects measure their y
422
-- position at their lower-left corner, instead
423
-- of their upper-left corner as usual
424
425
obj.y = obj.y - obj.height
426
end
427
428
-- create a new object if the class does exist
429
430
local spr
431
432
if _G[obj.name] then
433
obj.properties.x = obj.x
434
obj.properties.y = obj.y
435
obj.properties.width = obj.width
436
obj.properties.height = obj.height
437
438
spr = _G[obj.name]:new(obj.properties)
439
else
440
spr = Fill:new{ x = obj.x, y = obj.y, width = obj.width, height = obj.height, fill = { 128, 128, 128 } }
441
end
442
443
if obj.properties._the then
444
the[obj.properties._the] = spr
445
end
446
447
group:add(spr)
448
end
449
450
self[layer.name] = group
451
self:add(group)
452
else
453
error("don't know how to create a " .. layer.type .. " layer from file data")
454
end
455
end
456
else
457
error('could not load layers from file: ' .. data)
458
end
459
end,
460
461
-- passes startFrame events to member sprites
462
463
startFrame = function (self, elapsed)
464
if not self.active then return end
465
elapsed = elapsed * self.timeScale
466
467
for _, spr in pairs(self.sprites) do
468
if spr.active then spr:startFrame(elapsed) end
469
end
470
471
if self.onStartFrame then self:onStartFrame(elapsed) end
472
end,
473
474
-- passes update events to member sprites
475
476
update = function (self, elapsed)
477
if not self.active then return end
478
elapsed = elapsed * self.timeScale
479
480
for _, spr in pairs(self.sprites) do
481
if spr.active then spr:update(elapsed) end
482
end
483
484
if self.onUpdate then self:onUpdate(elapsed) end
485
end,
486
487
-- passes endFrame events to member sprites
488
489
endFrame = function (self, elapsed)
490
if not self.active then return end
491
elapsed = elapsed * self.timeScale
492
493
for _, spr in pairs(self.sprites) do
494
if spr.active then spr:endFrame(elapsed) end
495
end
496
497
if self.onEndFrame then self:onEndFrame(elapsed) end
498
end,
499
500
-- Method: draw
501
-- Draws all visible member sprites onscreen.
502
--
503
-- Arguments:
504
-- x - x offset in pixels
505
-- y - y offset in pixels
506
507
draw = function (self, x, y)
508
if not self.visible then return end
509
x = x or self.translate.x
510
y = y or self.translate.y
511
512
local scrollX = x * self.translateScale.x
513
local scrollY = y * self.translateScale.y
514
local appWidth = the.app.width
515
local appHeight = the.app.height
516
517
if self.effect then
518
if self.effectType == 'screen' then
519
if not self._canvas then self._canvas = love.graphics.newCanvas() end
520
self._canvas:clear()
521
love.graphics.setCanvas(self._canvas)
522
elseif self.effectType == 'sprite' then
523
love.graphics.setPixelEffect(self.effect)
524
end
525
end
526
527
for _, spr in pairs(self.sprites) do
528
if spr.visible then
529
if spr.translate then
530
spr:draw(spr.translate.x + scrollX, spr.translate.y + scrollY)
531
elseif spr.x and spr.y and spr.width and spr.height then
532
local sprX = spr.x + scrollX
533
local sprY = spr.y + scrollY
534
535
if sprX < appWidth and sprX + spr.width > 0 and
536
sprY < appHeight and sprY + spr.height > 0 then
537
spr:draw(sprX, sprY)
538
end
539
else
540
spr:draw(scrollX, scrollY)
541
end
542
end
543
end
544
545
if self.effect then
546
if self.effectType == 'screen' then
547
love.graphics.setPixelEffect(self.effect)
548
love.graphics.setCanvas()
549
love.graphics.draw(self._canvas)
550
end
551
552
love.graphics.setPixelEffect()
553
end
554
end,
555
556
__tostring = function (self)
557
local result = 'Group ('
558
559
if self.active then
560
result = result .. 'active'
561
else
562
result = result .. 'inactive'
563
end
564
565
if self.visible then
566
result = result .. ', visible'
567
else
568
result = result .. ', invisible'
569
end
570
571
if self.solid then
572
result = result .. ', solid'
573
else
574
result = result .. ', not solid'
575
end
576
577
return result .. ', ' .. self:count(true) .. ' sprites)'
578
end
579
}
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