CODEWITHSUNDEEP
javaperformanceswingpaintevent-dispatch-thread
Audiocrow
Audiocrow

Reputation: 65

Java Swing heavy/slow paintComponent - any advice?

I'm making a scrolling 2D map/tile based game. Each tile (stored as tile[21][11] - 231 tiles total per map) can contain up to 21 values (stored as int[3][7]). While full-screen I see about 8 maps at once.

On average, each map takes about 0.03 seconds to draw (found with System.nanoTime). The problem is that as soon as more than 1 map is on the screen, the Swing event polling noticeably slows down.

Is there any solution to this? I can't draw the map a single time to save it as an image because it has transparency involving moving actors, so it changes too frequently. Also I don't think I can call a thread in paintComponent to draw the maps without it glitching out, but I'm not positive.

Upvotes: 1

Views: 726

Answers (1)

trashgod
trashgod

Reputation: 205785

My Tiles aren't any type of JComponent, they're just data. I call their container the MapPane, which draws all of the tiles in its paintComponent.

Likewise, JTable cells are just data rendered inside a JComponent; the flyweight pattern, mentioned here, is still applicable: the goal is to omit any effort to render non-visible cells. Profile and self-time with a view toward optimizing the rendering; some approaches are examined in the KineticModel cited here.

A BufferedImage that needs no scaling is best. If you must scale, experiment with RenderingHints related to interpolation type. If composition is too expensive, construct maps in the background using SwingWorker; publish() them as they become available and process() them on the EDT, as shown here.

Upvotes: 3

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