Java-Gaming.org Hi !
Featured games (83)
games approved by the League of Dukes
Games in Showcase (539)
Games in Android Showcase (132)
games submitted by our members
Games in WIP (603)
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  
  Bitmask transparency  (Read 1206 times)
0 Members and 1 Guest are viewing this topic.
Offline mudman

Junior Devvie




Here we go again...


« Posted 2006-04-11 13:35:52 »

Since hardware acceleration of Java2d supports bitmask transparency shouldn't it be possible to use it in OpenGL too?
I can't seem to find anything indicating this.
(I understand there are 2 kinds of "bitmask" transparency - one is assigning a special color as transparent, the other is using a 1 bit black/white texture as bitmask. The last option would be preferrable)
Offline darkprophet

Senior Devvie




Go Go Gadget Arms


« Reply #1 - Posted 2006-04-12 23:56:59 »

tis called alpha testing Smiley

1  
2  
GL11.glEnable(GL11.GL_ALPHA_TEST);
GL11.glAlphaFunc( GL11.GL_GREATER, 0);


what that basically does is pass fragments through the test that have a transperancy of > 0, upon which it then goes through the stencil test (if enabled), then the depth test (if enabled) before being rasterised.

DP

Friends don't let friends make MMORPGs.

Blog | Volatile-Engine
Offline mudman

Junior Devvie




Here we go again...


« Reply #2 - Posted 2006-04-13 08:48:19 »

Then I would have to use RGBA images to make it work I think?
 Is there any way I can use a 1 bit black/white image to mask out a 24 bit RGB image, or define one of the colors in a 24 bit image as translucent? I would prefer being able to use masking, since this is for isometric tiles, and 50% of the rectangle containing a tile is transparent - that way I could save 50% space if I just used the same mask texture for all tiles.
I looked at polygon stipples, but they are only 32X32.
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline darkprophet

Senior Devvie




Go Go Gadget Arms


« Reply #3 - Posted 2006-04-13 09:12:18 »

I would suggest using RGBA, but define the internal format as RGB5_A1, that gives you 5 bits for each red, green and blue components and 1 bit for alpha resulting in a combined 16 bit image...

If you really really dont want RGBA, then your going to have to use multitexturing with one channel having RGBA8 and one having Alpha4; your still going to have to deal with the overhead of seperate textures and mulitexturing.

Look here for the internal format listing.

DP

Friends don't let friends make MMORPGs.

Blog | Volatile-Engine
Offline CaptainJester

JGO Knight


Medals: 12
Projects: 2
Exp: 14 years


Make it work; make it better.


« Reply #4 - Posted 2006-04-13 12:02:40 »

You could look at the NeHe tutorial that does just what you are trying to do.  It also includes the source in LWJGL.

http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=20

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.

rwatson462 (31 views)
2014-12-15 09:26:44

Mr.CodeIt (23 views)
2014-12-14 19:50:38

BurntPizza (50 views)
2014-12-09 22:41:13

BurntPizza (84 views)
2014-12-08 04:46:31

JscottyBieshaar (45 views)
2014-12-05 12:39:02

SHC (59 views)
2014-12-03 16:27:13

CopyableCougar4 (57 views)
2014-11-29 21:32:03

toopeicgaming1999 (123 views)
2014-11-26 15:22:04

toopeicgaming1999 (114 views)
2014-11-26 15:20:36

toopeicgaming1999 (32 views)
2014-11-26 15:20:08
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

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

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