本文没有追求任何实际目标-我只是想知道大约15年前，开发人员如何为当时的弱电开发出功能齐全的应用程序和游戏。
, floating-point , . "3" — fixed-point . , . , j2me Android.
, j2me — java (, 1.3), .jar PC. — . , - — API j2me .
.
, , , .
Nokia 5200, " " :
- 2006
- 128x160 1.8
- 262 . ( , 6 R, G, B ).
- - bluetooth .
- ( , 7 )
- microSd , , , 256 .
- - opera mini (, , )
- 640x480 .
- MIDP 2.0 (wiki)
- usb
- -
- , , — 100 , , floating-point . , - .
, — , 50-200 .
Write once, run everywhere
java . , . , platform- , .
, — . — . . , .jar j2me .class java. , Canvas, MIDlet javax.microedition.
, . Android : .class , .dex ( , .. dex 65 ), apk, ART.
, . , . , . , Vector synchronized. Vector , ArrayList ArrayList , .
— java . (int, boolean, ...) . Vector Object, .
, go , java 1.3. go - , java 2004 1.5 . 1.3.
j2me — .jar .class ( 1.3, 20 ), Gravity defied PC. "" java javax.microedition , . , : , java.awt.Image javax.microedition.lcdui.Image.
J2ME
javax.microedition. , - , , - , , — . javax.microedition.lcdui.
MIDlet.
startApp().
— pauseApp() startApp() . destroyApp().
, notifyPaused() notifyDestroyed() — , .
, " " resumeRequest()
, notifyPaused(), , .
, lifecycle .
, Runnable - :
Thread thread;
boolean isRunning;
boolean needToDestroy = false;
public void startApp() {
isRunning = true;
if (thread != null) {
thread = new Thread(this);
thread.start();
}
}
public void pauseApp() {
isRunning = false;
}
public void destroyApp(boolean unconditional) {
needToDestroy = true;
}
, .
void run(){
while(!needToDestroy) {
while (!isRunning) {
Thread.sleep(100);
}
}
notifyDestroyed();
}
, 100 — , . , pauseApp() startApp()
Canvas
— Canvas. Canvas java.
repaint(), , . UI- paint(Graphics g). , - , Canvas — . — repaint() paint(...) .
, :
hasPointerEvents(), hasPointerMotionEvents(), hasRepeatEvents(), true. pointerDragged(int x, int y) ( ), pressed( ) released( ).
— , .
, — , . . , , . , 240360 . — — .
- , "" , . j2me - , , .., . , nokia 5800 , .
MIDlet Pascal
- , . java2me , , MIDlet pascal . j2me — , , java.
?
, , , Gravity Defied 64 .
-, .jar — zip , 122.1 kB
- META-INF MANIFEST.MF 3.8 kB, SHA-1 MD5 . .
- levels.mrg 5.1 kB 30 . 170 . .
- 11 . 10.8 kB.
- .class , 98.3 kB, 15 . — 127 , 24.3 kB. :
- , (4 ), 127 174 .
- — 470 .
- 9 — 1.6 6 kB.
- god-like :
. fernflower — , intelliJ IDEA. — , . .
IDEA — , .
: /gradlew jar, build .jar
: mkdir decompiled && java -jar fernflower.jar -ren=1 GravityDefied_java decompiled
ren , if for. , java . ren=1 field_42 method_135 — , .
2004 — , , :
- - , . .class .
else, int ..- . "" Micro, .
- , fixed-point , . ,
(int)((long)a * b >> 16) - , , .
— , . , , -. , .
- Netbeans, j2me SDK. , , ant. .
, Linux. gradle . — javax.microedition.*. — PC- java. . , .
watch ./gradlew run . ctrl+S .
.
19 :
- 8 javax.microedition.rms.
- 10 .lcdui, , , Canvas ..).
- MIDlet — , .
, .
Micro, . - , startApp MIDlet .
:
protected void pauseApp() {
c = true;
if (!b) {
this.gameToMenu();
}
System.gc();
}
, c isPaused.
"" :
public void a() {
if (this.recordStore != null) {
try {
this.e.closeRecordStore();
return;
} catch (RecordStoreException var1) {
}
}
}
- closeMethodStore.
, intelliJ IDEA - . — , , Image.loadImage(name):
this.p = Image.createImage("/splash.png");
, p splashImage.
- — , . , … Jetbrains — , — . , , .
- . — loadImage()… null . .
: , Image:
public class Image {
public final java.awt.Image image;
private Image(java.at.Image image) {
this.image = image;
}
public Graphics getGraphics() {
throw new RuntimeException();
}
public int getWidth() {
return image.getWidth(null);
}
public static Image createImage(int w, int h) {
return new Image(new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB));
}
...
}
, API , .
CanvasImpl, JPanel. Canvas.
, c :
public void paintComponent(Graphics g) {
if (upscale == 1) {
canvas.paint(new javax.microedition.lcdui.Graphics(g));
} else {
canvas.paint(new javax.microedition.lcdui.Graphics(screen.getGraphics()));
g.drawImage(screen, 0, 0, width * upscale, height * upscale, Color.WHITE, null);
}
}
javax.microedition.lcdui.Graphics(g) — awt.Graphics, .
, . "" , .
, , , , — . PC. ? - 64 * 64, , 1 * 1 , 240 * 320 . , , , , .
, . , , , , , .
, , j2me PC. — 2010 -, - . - - — .
!
, .
.jar . . , , . - Alert Canvas Displayable , Canvas. , .
gradle :
- emulator , , . , , .
- app-original, .jar
- app-from-sources - . .
, , . "" , , .
, .
Fixed-point physics
. , 16 — . , , -32768.0 32767.999984 c 1.0 / 65536.
— .
int.
: int, , "". long. 64 32 . 16 16- int.
: . long, 16 . - , 32 — 16.
sin, cos atan2.
— 64 — 0 90 . , — . . , .
, . Canvas.hasPointerEvents() true, , . — " ", " ", " " - "" . , , .
, — 170 . ? — .
, — / .., . . 0xff, int , , — dx , dy.
for (int i = 1; i < pointsCount; ++i) {
byte modeOrDx;
if ((modeOrDx = var1.readByte()) == -1) {
offsetY = 0;
offsetX = 0;
pointX = var1.readInt();
pointY = var1.readInt();
} else {
pointX = modeOrDx;
pointY = var1.readByte();
}
offsetX += pointX;
offsetY += pointY;
this.addPointSimple(offsetX, offsetY);
}
.
GPU full hd , (128*160 240*320). 3 - , api . , — 90-180-270 .
, — .
, 32 16 . 48*48 1091 .
, , - API 3 3 - 3-. , - .
— 2 3.
. — 100 "23" "64".
if (time10MsToStringCache[time10MsPart] == null) {
String zeroPadding;
if (time10MsPart >= 10) {
zeroPadding = "";
} else {
zeroPadding = "0";
}
time10MsToStringCache[time10MsPart] = zeroPadding + time10Ms % 100L;
}
, , . , -.
No-MVP
MenuManager ( ) . - , — - , .
, - , . : Android:
- layout . .
- stings.txt.
- Activity, .
- LifecycleObserver, Adapter , Activity .
- Adapter DataSource.
- " ", Bundle DataSource .
- DataSouce SQLite .
: , ? , .
, TimerOrMotoPartOrMenuElem .
, , :
, , , — .
, , 64 . , - , "" .
, , , , . ", " — .
:
public void init() {
long timeToLoading = 3000L;
Thread.yield();
this.gameCanvas = new GameCanvas(this);
Display.getDisplay(this).setCurrent(this.gameCanvas);
this.gameCanvas.requestRepaint(1);
while (!this.gameCanvas.isShown()) {
this.goLoadingStep();
}
long deltaTimeMs;
while (timeToLoading > 0L) {
deltaTimeMs = this.goLoadingStep();
timeToLoading -= deltaTimeMs;
}
this.gameCanvas.requestRepaint(2);
for (timeToLoading = 3000L; timeToLoading > 0L; timeToLoading -= deltaTimeMs) {
deltaTimeMs = this.goLoadingStep();
}
while (gameLoadingStateStage < 10) {
this.goLoadingStep();
}
this.gameCanvas.requestRepaint(0);
this.isInited = true;
}
goLoadingStep() . goLoadingStep(). goLoadingStep , .
goLoadingStep() :
private long goLoadingStep() {
++gameLoadingStateStage;
this.gameCanvas.repaint();
long startTimeMillis = System.currentTimeMillis();
switch (gameLoadingStateStage) {
case 1:
this.levelLoader = new LevelLoader();
break;
case 2:
this.gamePhysics = new GamePhysics(this.levelLoader);
this.gameCanvas.init(this.gamePhysics);
break;
case 3:
this.menuManager = new MenuManager(this);
this.menuManager.initPart(1);
break;
....
case 9:
this.menuManager.initPart(7);
break;
case 10:
this.gameCanvas.setMenuManager(this.menuManager);
this.gameCanvas.setViewPosition(-50, 150);
this.setMode(1);
break;
default:
--gameLoadingStateStage;
try {
Thread.sleep(100L);
} catch (InterruptedException var3) {
}
}
return System.currentTimeMillis() - startTimeMillis;
}
MenuManager.initPart() switch case .
, , . , .
2004 . Excitera Mobile Awards 2004 (EMA04) best-in-show. Codebrew Software :
- Tors Björn Henrik Johansson — system/game logic/interface, testing, levels design
- Set Elis Norman — graphics/physics/mathematics/system/tools programming, levels design
- Per David Jacobsson — physics programming, game graphics, levels design
此外，我们的同胞为Android制作了这个游戏的端口，但它只是使用了反编译的代码。
由于五年来一直没有对该代码的投诉，因此，我认为我尝试反编译原始应用程序并理解它不会造成任何伤害。现在，该游戏具有历史意义，可以让您更仔细地了解小型智能手机的时代。