Hi !
Featured games (91)
games approved by the League of Dukes
Games in Showcase (757)
Games in Android Showcase (229)
games submitted by our members
Games in WIP (844)
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  
  alphacomposite for a 2d lightmap?  (Read 1400 times)
0 Members and 1 Guest are viewing this topic.
Offline fabel

Innocent Bystander

Java games rock!

« Posted 2004-10-03 04:27:58 »

I did a couple of searches and didnt see any answer for this so here goes. I have been playing with setting different alpha modes for blending an image and i havent been able to get the effect im looking for. I know how to do it all manually by updating pixels but i was hoping there was a way to do it without resorting to that =). I have a Buffered Image that Im using for a background. Then I have a grayscale image for a light map I want white to basically be 100% transparent and the shades of gray to black to to darken the pixels behind them. I think I have tied all the blending modes with no luck but am I just missing something? It actually looks pretty decent except blening pure white makes the background look washed out in those areas.
Offline crystalsquid

Junior Devvie

... Boing ...

« Reply #1 - Posted 2004-10-03 08:35:36 »

Not easy - what you really need is a multiplicative blend, but that needs a pixel shader.

You may get away with a 'subtractive' blend if you invert the lightmap - so black is 'clear' (no change to undlying colour) and white will end up as black. You sometimes get some funny colours appearing though, but its not too bad usually

All in all, your probably best doing it yourself with the pixels & rebuilding the image - at least that way you can do it right Smiley

- Dom
Pages: [1]
  ignore  |  Print  

EgonOlsen (76 views)
2018-06-10 19:43:48

EgonOlsen (56 views)
2018-06-10 19:43:44

EgonOlsen (76 views)
2018-06-10 19:43:20

DesertCoockie (256 views)
2018-05-13 18:23:11

nelsongames (156 views)
2018-04-24 18:15:36

nelsongames (155 views)
2018-04-24 18:14:32

ivj94 (896 views)
2018-03-24 14:47:39

ivj94 (157 views)
2018-03-24 14:46:31

ivj94 (809 views)
2018-03-24 14:43:53

Solater (173 views)
2018-03-17 05:04:08
Java Gaming Resources
by philfrei
2017-12-05 19:38:37

Java Gaming Resources
by philfrei
2017-12-05 19:37:39

Java Gaming Resources
by philfrei
2017-12-05 19:36:10

Java Gaming Resources
by philfrei
2017-12-05 19:33:10

List of Learning Resources
by elect
2017-03-13 14:05:44

List of Learning Resources
by elect
2017-03-13 14:04:45

SF/X Libraries
by philfrei
2017-03-02 08:45:19

SF/X Libraries
by philfrei
2017-03-02 08:44:05 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!