Java-Gaming.org Hi !
 Featured games (90) games approved by the League of Dukes Games in Showcase (753) Games in Android Showcase (228) games submitted by our members Games in WIP (842) 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
 Rotate an image with AffineTransform without coordinate change.  (Read 3574 times) 0 Members and 1 Guest are viewing this topic.
.

Junior Newbie

 « Posted 2012-10-04 11:31:01 »

I have a game that i am making, where a ship is in the centre of the screen and planets scroll around it. The ship can rotate about it's centre, but can not change position.(the planets do that, for a scrolling effect) The problem is that I don't know how to move the planets in a certain direction based on where the ship is pointing. my first approach was to increment the planet's x and y coordinates based on where the ship was. example:
 1  2  3  4 `if(ships_rotation > 22.5 && ships rotation < 67.5){            planet.x-= ship.y*speed;            planet.y+= ship.y*speed;            }`
However this is very time-consuming because I have to write similar code for every direction the planet moves, as well as having very choppy movement. So I decided to attach a AffineTransform to the planet, because as i have found out earlier, AffineTransform can rotate coordinates. This next block of code shows an example of moving the ship diagonally just by incrementing x.
 1  2 `        aft.rotate(Math.toRadians(45));        aft.translate(50,0);`
However, there is one thing wrong with this code, and it is that the image rotates WITH the coordinates. My new approach is to rotate the image opposite the way I want it to go WITHOUT coordinate change, then rotate it back normally.(So the coordinates change) How can I accomplish this? I am open to other solutions, but NOT installing libraries. Thanks in advance.
ReBirth
 « Reply #1 - Posted 2012-10-04 13:04:01 »

Set/translate to the center of the image.

Roquen

JGO Kernel

Medals: 517

 « Reply #2 - Posted 2012-10-04 14:58:57 »

I'm not really understanding your description.  The ship can rotate, but is always "shown" at the center of the screen.  The ship moves, it's just the "camera" is always keeping it in the center (so planets don't move when the ship does).
 Games published by our own members! Check 'em out!
.

Junior Newbie

 « Reply #3 - Posted 2012-10-04 19:51:03 »

I'm not really understanding your description.  The ship can rotate, but is always "shown" at the center of the screen.  The ship moves, it's just the "camera" is always keeping it in the center (so planets don't move when the ship does).
The ship turns, but stays in the center. The planets go past the ship to create a "moving" effect.
Pages: [1]
 ignore  |  Print

 ivj94 (581 views) 2018-03-24 14:47:39 ivj94 (45 views) 2018-03-24 14:46:31 ivj94 (372 views) 2018-03-24 14:43:53 Solater (60 views) 2018-03-17 05:04:08 nelsongames (107 views) 2018-03-05 17:56:34 Gornova (148 views) 2018-03-02 22:15:33 buddyBro (690 views) 2018-02-28 16:59:18 buddyBro (90 views) 2018-02-28 16:45:17 xxMrPHDxx (492 views) 2017-12-31 17:17:51 xxMrPHDxx (729 views) 2017-12-31 17:15:51
 Java Gaming Resourcesby philfrei2017-12-05 19:38:37Java Gaming Resourcesby philfrei2017-12-05 19:37:39Java Gaming Resourcesby philfrei2017-12-05 19:36:10Java Gaming Resourcesby philfrei2017-12-05 19:33:10List of Learning Resourcesby elect2017-03-13 14:05:44List of Learning Resourcesby elect2017-03-13 14:04:45SF/X Librariesby philfrei2017-03-02 08:45:19SF/X Librariesby philfrei2017-03-02 08:44:05
 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