Java-Gaming.org    
Featured games (81)
games approved by the League of Dukes
Games in Showcase (497)
Games in Android Showcase (114)
games submitted by our members
Games in WIP (563)
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  
  Keeping two objects on the screen?  (Read 1176 times)
0 Members and 1 Guest are viewing this topic.
Offline CyanPrime
« Posted 2009-05-16 01:19:24 »

I'm trying to make it so that no matter how far apart two objects are they'll both remain on screen.
This is what I got so far:

float distance = (float) ((Math.sqrt((p1.x - p2.x) + (p1.y - p2.y))));
float camx = (float)((p1.x + p2.x) * 0.5);
float camy = (float)((p1.y + p2.y) * 0.5);
float camz = (float) (distance * 5);

What is the math I need so the Z zooms in and out correctly?
Offline lhkbob

JGO Knight


Medals: 32



« Reply #1 - Posted 2009-05-16 04:05:16 »

One that should help is that distance should be:
1  
float distance = (float) Math.sqrt( (p1.x - p2.x)*(p1.x - p2.x) + (p1.y - p2.y)*(p1.y - p2.y) );


To calculate the distance needed, try this:
1  
2  
3  
4  
5  
float width = Math.abs(p1.x - p2.x) + PADDING;
float camx = (float) ( (p1.x + p2.x) * .5);
float camy = (float) ( (p1.y + p2.y) * .5);

float camz = (float) (.5 * width * Math.tan(.5 * fov));


The only things I've added are PADDING (which would be a constant that just affects how much space between the edges of the screen you want), and the variable fov.  fov is the field of view angle that you're using when rendering.  If you're using JOGL, it's one of the values used in gluPerspective(), probably 60 degrees.

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.

BurntPizza (24 views)
2014-09-19 03:14:18

Dwinin (39 views)
2014-09-12 09:08:26

Norakomi (68 views)
2014-09-10 13:57:51

TehJavaDev (93 views)
2014-09-10 06:39:09

Tekkerue (47 views)
2014-09-09 02:24:56

mitcheeb (68 views)
2014-09-08 06:06:29

BurntPizza (51 views)
2014-09-07 01:13:42

Longarmx (38 views)
2014-09-07 01:12:14

Longarmx (44 views)
2014-09-07 01:11:22

Longarmx (40 views)
2014-09-07 01:10:19
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!