Hi !
Featured games (84)
games approved by the League of Dukes
Games in Showcase (549)
Games in Android Showcase (135)
games submitted by our members
Games in WIP (593)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  Copying a 2 Dim Array into a 1 dim array  (Read 1682 times)
0 Members and 1 Guest are viewing this topic.
Offline Mojomonkey

Senior Devvie

ooh ooh eee eeee

« Posted 2003-07-09 19:27:34 »

Is there any speedier ways to copy a uniform (i.e. square) two dimesional array into a single dimesional array?

Something faster than:
float[][] source = new float[size][size];
float[] target = new float[size * size];

// .... source is filled

for(int i = size; i < size; i++) {
    for(int j = size; j < size; j++) {
        target[j*size + i] = source[i][j];

Don't send a man to do a monkey's work.
Offline nickdotjava

Junior Devvie

I have fallen to the dark side. &nbsp;I'm using DX9

« Reply #1 - Posted 2003-07-09 19:41:37 »

As far as I know, that's the way to do it.

And is that the actual code, or something quickly written for the post?  There are a few bugs (loops never entered)...


"Oh ya, that's trivial.  I should have it done in an hour."
Offline Mojomonkey

Senior Devvie

ooh ooh eee eeee

« Reply #2 - Posted 2003-07-09 19:45:29 »

just wrote something up real quick for the post.

Don't send a man to do a monkey's work.
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline mik

Senior Newbie

Java games rock everywhere!

« Reply #3 - Posted 2003-07-09 20:41:40 »

and a System.arraycopy instead of the second loop?
like :
for (int i = 0; i < size; i++)
  System.arraycopy(source, 0, target, i*size, size);

as the source and the target have same type


Offline tortoise

Junior Devvie

<3 Shmups

« Reply #4 - Posted 2003-07-12 00:49:15 »

Sun would claim arraycopy is faster. I don't remember the details on that method but it uses some native trickery to boost its speed.
Offline princec

« JGO Spiffy Duke »

Medals: 452
Projects: 3
Exp: 16 years

Eh? Who? What? ... Me?

« Reply #5 - Posted 2003-07-12 05:07:19 »

Arraycopy only has to do one bounds check.
The server VM should eliminate the bounds checks and also remove the native call overhead but it's probably neck and neck. But because almost no-one has the server VM (grrr!) you'll be better off with the arraycopy method I suspect.

Cas Smiley

Pages: [1]
  ignore  |  Print  
You cannot reply to this message, because it is very, very old.


Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

Robo11 (9 views)
2015-01-25 06:14:26

basil_ (25 views)
2015-01-17 22:29:32

wxwsk8er (21 views)
2015-01-16 21:42:21

wxwsk8er (19 views)
2015-01-16 20:44:20

basil_ (25 views)
2015-01-14 09:46:59

basil_ (20 views)
2015-01-14 09:46:52

wxwsk8er (30 views)
2015-01-13 20:42:16

wxwsk8er (33 views)
2015-01-13 03:23:59

vctt (53 views)
2015-01-12 03:21:07

wxwsk8er (31 views)
2015-01-12 03:11:59
2D Dynamic Lighting
by ThePixelPony
2015-01-01 20:25:42

How do I start Java Game Development?
by gouessej
2014-12-27 19:41:21

Resources for WIP games
by kpars
2014-12-18 10:26:14

Understanding relations between setOrigin, setScale and setPosition in libGdx
by mbabuskov
2014-10-09 22:35:00

Definite guide to supporting multiple device resolutions on Android (2014)
by mbabuskov
2014-10-02 22:36:02

List of Learning Resources
by Longor1996
2014-08-16 10:40:00

List of Learning Resources
by SilverTiger
2014-08-05 19:33:27

Resources for WIP games
by CogWheelz
2014-08-01 16:20:17 is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!