Java-Gaming.org    
Featured games (81)
games approved by the League of Dukes
Games in Showcase (499)
Games in Android Showcase (118)
games submitted by our members
Games in WIP (567)
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  
  Ways to make a good tower defense tower  (Read 998 times)
0 Members and 1 Guest are viewing this topic.
Offline Slyth2727
« Posted 2013-01-17 02:58:51 »

I have been developing a simple tower defense game in plain java for the past month. I want to make my game a little better so I am adding a cannon, which needs to be able to rotate according to the enemy's position on the screen. Thats my big problem... I have made 8 images of the tower in different positions and I am not sure whether or not I can actually use Java to rotate a single image, or do I have to have a sprite sheet of the tower in different directions? Also, how do I detect which way for it to face? I was thinking about comparing the slope of the x and y coordinates of the enemy and the tower, but I wasnt sure if that was efficient, so I came here. Help is appreciated
cMp

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
Offline HeroesGraveDev

JGO Kernel


Medals: 259
Projects: 11
Exp: 2 years


┬─┬ノ(ಠ_ಠノ)(╯°□°)╯︵ ┻━┻


« Reply #1 - Posted 2013-01-17 03:02:22 »

Yes, you can use java to rotate the image.

Use Google.

Offline Agro
« Reply #2 - Posted 2013-01-17 03:03:54 »

Yeah, for this one you're going to have to use trigonometry. More specifically, the atan2 function.

So, what you need to do is get the closest enemy, and calculate the angle to it. To do this, do:

1  
double angle = Math.atan2(target.x - this.x, target.y, - this.y);


That will be in radians, of course, so put a Math.toDegrees(x) around that for degrees.

Now, it'll be easier to do in degrees, so you should convert to that. We have to divide 360 into 8 parts, which is 45. So what you're going to do is something like this

1  
2  
3  
4  
5  
if(angle >= 0 && angle < 45) {
    sprite is this
} else if(angle >= 45 && angle < 90) {
    sprite is that
}


But then again, it all matters on perspective, this way would be useful in basically all possible perspectives, but your game has a bird-eye view, it would be easier to rotate the image.

Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline Slyth2727
« Reply #3 - Posted 2013-01-17 03:06:54 »

yes, it has a birds eye view, so I am guessing that I would use the same concept but for rotation?

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
Offline HeroesGraveDev

JGO Kernel


Medals: 259
Projects: 11
Exp: 2 years


┬─┬ノ(ಠ_ಠノ)(╯°□°)╯︵ ┻━┻


« Reply #4 - Posted 2013-01-17 03:09:28 »

You can use graphics.rotate() or glRotatef() (depending on your rendering) to rotate the image.

Offline Jimmt
« League of Dukes »

JGO Kernel


Medals: 133
Projects: 4
Exp: 3 years



« Reply #5 - Posted 2013-01-17 03:16:39 »

He said "plain java" which I assume means Java2D...in that case better to use AffineTransform, then you can rotate individual images as opposed to the entire graphics object
Offline Slyth2727
« Reply #6 - Posted 2013-01-17 03:18:47 »

I will research both of the methods. Thank you very much for all of your help!

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
Offline Slyth2727
« Reply #7 - Posted 2013-01-17 03:19:34 »

Bingo. Exactly what I was searching for. Agro, I swear you are a super human genius your awesome!

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
Offline Agro
« Reply #8 - Posted 2013-01-17 03:37:22 »

Nah, its just that just 2 days ago, we learned what sin, cos, and tan were, so I got a much better understanding of it than I had before. I also worked on an isometric tower defense game before this and I had your same problems, and I just give you the solutions I got, but a bit different since I had isometric.

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.

Pippogeek (38 views)
2014-09-24 16:13:29

Pippogeek (29 views)
2014-09-24 16:12:22

Pippogeek (18 views)
2014-09-24 16:12:06

Grunnt (42 views)
2014-09-23 14:38:19

radar3301 (24 views)
2014-09-21 23:33:17

BurntPizza (61 views)
2014-09-21 02:42:18

BurntPizza (31 views)
2014-09-21 01:30:30

moogie (36 views)
2014-09-21 00:26:15

UprightPath (49 views)
2014-09-20 20:14:06

BurntPizza (53 views)
2014-09-19 03:14:18
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

Resources for WIP games
by CogWheelz
2014-08-01 16:19:50

List of Learning Resources
by SilverTiger
2014-07-31 16:29:50

List of Learning Resources
by SilverTiger
2014-07-31 16:26:06

List of Learning Resources
by SilverTiger
2014-07-31 11:54:12

HotSpot Options
by dleskov
2014-07-08 01:59:08
java-gaming.org 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‑gaming.org
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!