view src/net/kryshen/indyvon/async.clj @ 88:18abc7d66d49

Async-layer uses daemon thread. Added arg to set the thread priority.
author Mikhail Kryshen <mikhail@kryshen.net>
date Wed, 06 Oct 2010 18:45:51 +0400
parents e718a69f7d99
children dd7b8dbb20bc
line source
1 ;;
2 ;; Copyright 2010 Mikhail Kryshen <mikhail@kryshen.net>
3 ;;
4 ;; This file is part of Indyvon.
5 ;;
6 ;; Indyvon is free software: you can redistribute it and/or modify it
7 ;; under the terms of the GNU Lesser General Public License version 3
8 ;; only, as published by the Free Software Foundation.
9 ;;
10 ;; Indyvon is distributed in the hope that it will be useful, but
11 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
12 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ;; Lesser General Public License for more details.
14 ;;
15 ;; You should have received a copy of the GNU Lesser General Public
16 ;; License along with Indyvon. If not, see
17 ;; <http://www.gnu.org/licenses/>.
18 ;;
20 (ns net.kryshen.indyvon.async
21 "Asynchronous drawing."
22 (:use
23 net.kryshen.indyvon.core)
24 (:import
25 (net.kryshen.indyvon.core Size Location)
26 (java.awt Image)
27 (java.awt.image BufferedImage)
28 (java.util.concurrent ThreadFactory ThreadPoolExecutor
29 ThreadPoolExecutor$DiscardOldestPolicy
30 ArrayBlockingQueue TimeUnit)))
32 (defrecord Buffer [id image readers state])
33 ;; Buffer states:
34 ;; :front, readers > 0
35 ;; being copied on screen
36 ;; :back
37 ;; being rendered to (offscreen)
38 ;; :fresh
39 ;; most recently updated
40 ;; :free
41 ;; not in use
43 (defn- create-image [async-layer]
44 ;; TODO: support different image types.
45 (BufferedImage. (:width async-layer) (:height async-layer)
46 BufferedImage/TYPE_INT_ARGB_PRE))
48 (defn- create-buffer [async-layer]
49 (Buffer. (Object.) (create-image async-layer) 0 :free))
51 (defn- find-buffer
52 "Find a buffer with the one of the specified states given
53 in the order of preference."
54 [buffers & states]
55 (some identity
56 (for [state states]
57 (some #(if (= (:state %) state) % nil) buffers))))
59 (defn- replace-buffer [buffers buffer]
60 (conj (remove #(= (:id %) (:id buffer)) buffers)
61 buffer))
63 (defn- take-buffer [al type]
64 (dosync
65 (let [buffers @(:buffers al)
66 b (case type
67 :front (find-buffer buffers :front :fresh :free)
68 :back (find-buffer buffers :free :fresh)
69 (throw (IllegalArgumentException.)))
70 readers (if (= type :front)
71 (inc (:readers b))
72 (:readers b))
73 b (assoc b
74 :state type
75 :readers readers)]
76 (alter (:buffers al) replace-buffer b)
77 b)))
79 (defn- release-buffer [al buffer]
80 (dosync
81 (let [state (:state buffer)
82 readers (if (= state :front)
83 (dec (:readers buffer))
84 (:readers buffer))
85 fresh (delay (find-buffer @(:buffers al) :fresh))
86 state (cond
87 (pos? readers) :front
88 (= :back state) :fresh
89 @fresh :free
90 :default :fresh)]
91 (if (and (= state :fresh) @fresh)
92 ;; Change state of the prefiously fresh buffer to :free.
93 (alter (:buffers al)
94 replace-buffer (assoc @fresh
95 :state :free)))
96 (alter (:buffers al)
97 replace-buffer (assoc buffer
98 :state state
99 :readers readers)))))
101 (defmacro with-buffer
102 {:private true}
103 [al type [name] & body]
104 `(let [al# ~al
105 ~name (take-buffer al# ~type)]
106 (try
107 ~@body
108 (finally
109 (release-buffer al# ~name)))))
111 (defn- draw-offscreen [async-layer]
112 ;;(Thread/sleep 1000)
113 (with-buffer async-layer :back [b]
114 (draw-root! (:content async-layer)
115 (.getGraphics ^Image (:image b))
116 (:width async-layer)
117 (:height async-layer)
118 ;; TODO: use operational event dispatcher.
119 dummy-event-dispatcher))
120 (update async-layer))
122 (defn- draw-offscreen-async [async-layer]
123 (.execute ^ThreadPoolExecutor (:executor async-layer)
124 #(draw-offscreen async-layer)))
126 (defrecord AsyncLayer [content width height executor buffers]
127 Layer
128 (render! [layer]
129 (repaint-on-update layer)
130 (add-context-observer content (fn [_ _] (draw-offscreen-async layer)))
131 (when-not @buffers
132 ;; TODO: dynamic size, recreate buffers when size increases.
133 (let [new-buffers (repeatedly 2 (partial create-buffer layer))]
134 (dosync
135 (ref-set buffers new-buffers)))
136 (draw-offscreen-async layer))
137 (with-buffer layer :front [b]
138 (.drawImage *graphics* ^Image (:image b) 0 0 nil)))
139 (layer-size [layer]
140 (Size. width height)))
142 (defn- create-thread-factory [priority]
143 (reify
144 ThreadFactory
145 (newThread [_ runnable]
146 (let [thread (Thread. runnable)]
147 (when priority
148 (.setPriority thread priority))
149 (.setDaemon thread true)
150 thread))))
152 (defn- create-executor [priority]
153 (doto (ThreadPoolExecutor.
154 (int 1) (int 1)
155 (long 0) TimeUnit/SECONDS
156 (ArrayBlockingQueue. 1)
157 (ThreadPoolExecutor$DiscardOldestPolicy.))
158 (.setThreadFactory (create-thread-factory priority))))
160 (defn async-layer
161 "Creates layer that draws the content asynchronously using
162 offscreen buffer."
163 ([content width height]
164 (async-layer content width height nil))
165 ([content width height priority]
166 (AsyncLayer. content width height
167 (create-executor priority)
168 (ref nil))))